ANTHROPOLOGICAL PAPERS OF THE AMERICAN MUSEUM OF NATURAL HISTORY

Number 98: 496 pp. June 14, 2013

Copyright © American Museum of Natural History 2013

ISSN 0065-9452

http://dx.doi.org/10.5531/sp.anth.0098

[PART 1 OF EPUB]

LIFE AMONG THE TIDES: RECENT ARCHAEOLOGY ON THE GEORGIA BIGHT

VICTOR D. THOMPSON

AND

DAVID HURST THOMAS

EDITORS AND CONTRIBUTORS

WITH CONTRIBUTIONS BY

Clark R. Alexander, Keith H. Ashley, Elliot H. Blair,

Ann S. Cordell, Kathleen A. Deagan, Chester B. DePratter, Scott M. Fitzpatrick, Ervan G. Garrison, Royce H. Hayes, Richard W. Jefferies, Deborah A. Keene, Ginessa J. Mahar, Rochelle A. Marrinan, Christopher R. Moore, Matthew F. Napolitano, Alexandra L. Parsons, Vicki L. Rolland, Matthew C. Sanger, Ryan O. Sipe, Amanda D. Roberts Thompson, Robert L. Thunen, John A. Turck, Neill J. Wallis, and Thomas G. Whitley

Proceedings of the Sixth Caldwell Conference

St. Catherines Island, Georgia

May 20–22, 2011

ABSTRACT

Although this volume covers a broad range of temporal and methodological topics, the chapters are unified by a geographic focus on the archaeology of the Georgia Bight. The various research projects span multiple time periods (including Archaic, Woodland, Mississippian, and contact periods) and many incorporate specialized analyses (such as petrographic point counting, shallow geophysics, and so forth). The 26 contributors conducting this cutting-edge work represent the full spectrum of the archaeological community, including museum, academic, student, and contract archaeologists. Despite the diversity in professional and theoretical backgrounds, temporal periods examined, and methodological approaches pursued, the volume is unified by four distinct, yet interrelated, themes.

Contributions in Part I discuss a range of analytical approaches for understanding time, exchange, and site layout. Chapters in Part II model coastal landscapes from both environmental and social perspectives. The third section addresses site-specific studies of late prehistoric architecture and village layout throughout the Georgia Bight. Part IV presents new and ongoing research into the Spanish mission period of this area.

These papers were initially presented and discussed at the Sixth Caldwell Conference, cosponsored by the American Museum of Natural History and the St. Catherines Island Foundation, held on St. Catherines Island, Georgia, May 20–22, 2011.

PARTICIPANTS IN THE SIXTH CALDWELL CONFERENCE

Clark R. Alexander (Professor, Skidaway Institute of Oceanography and Director, Applied Coastal Research Laboratory, Georgia Southern University)

Keith H. Ashley (Research Coordinator, Department of Sociology and Anthropology, University of North Florida)

Gale A. Bishop (Director, St. Catherines Island Sea Turtle Program and Professor Emeritus, Georgia Southern University)

Elliot H. Blair (Ph.D. student, Department of Anthropology, University of California, Berkeley and American Museum of Natural History)

Ann S. Cordell (Staff Archaeologist, Florida Museum of Natural History)

Scott M. Fitzpatrick (Associate Professor, Department of Anthropology, University of Oregon)

Christina M. Friberg (Ph.D. student, Department of Anthropology, University of California, Santa Barbara and American Museum of Natural History)

Royce H. Hayes (Superintendent, St. Catherines Island)

Richard W. Jefferies (Professor, Department of Anthropology, University of Kentucky)

Ginessa J. Mahar (Ph.D. student, Department of Anthropology, University of Florida and American Museum of Natural History)

Matthew F. Napolitano (Lab Supervisor, Nels Nelson North American Archaeology Laboratory, American Museum of Natural History and University of West Florida)

Alexandra L. Parsons (Archeologist, Southeast Archeological Center and Florida State University)

Lorann S.A. Pendleton (Director, Nels Nelson North American Archaeology Laboratory, American Museum of Natural History)

Diana Rosenthal (Senior Archivist/Editor, Nels Nelson North American Archaeology Laboratory, American Museum of Natural History)

Matthew C. Sanger (Ph.D. student, Department of Anthropology, Columbia University and Analyst, Nels Nelson North American Archaeology Laboratory, American Museum of Natural History)

Anna M. Semon (Ph.D. Student, Department of Anthropology, University of North Carolina, Chapel Hill and American Museum of Natural History)

Ryan O. Sipe (Master’s student, Department of Anthropology, Georgia Southern University)

David Hurst Thomas (Curator of Anthropology, American Museum of Natural History)

Victor D. Thompson (Assistant Professor, Department of Anthropology, University of Georgia)

Neill J. Wallis (Assistant Curator of Florida Archaeology, Florida Museum of Natural History)

Thomas G. Whitley (Archaeologist, Department of Archaeology, Western Australia University)

Mark Williams (Sr. Academic Professional, Director, Georgia Archaeological Site Files, Director, Laboratory of Archaeology, University of Georgia)

Participants in the Sixth Caldwell Conference, standing near an exposed sea turtle nest at South Beach, May 20–22, 2011: (left to right) Elliot Blair, Dave Thomas, Victor Thompson, Dick Jefferies, Alex Parsons, Matt Sanger, Lori Pendleton (in front), Ryan Sipe, Clark Alexander (in back), Diana Rosenthal (in front), Tom Whitley, Christa Hayes, Royce Hayes, Matt Napolitano, Anna Semon, Keith Ashley, Ann Cordell, Neill Wallis, Scott Fitzpatrick, Christina Friberg (seated in front, left), and Ginessa Mahar (seated in front).

PREFACE

Victor D. Thompson and David Hurst Thomas

LIFE AMONG THE TIDES

This book—and the conference it describes—had a somewhat different genesis from the other titles in the Caldwell Conference series.

We originally envisioned Life Among the Tides: Recent Archaeology on the Georgia Bight as a book highlighting current archaeological research along the Georgia Bight. But as we read drafts of the papers being submitted, we realized that all of us would benefit from the Caldwell format, allowing the participants to come together in a congenial setting to discuss already well-developed papers. This is how the Sixth Caldwell Conference was born. Most of the papers in this volume were presented at that conference, held May 20–22, 2011 on St. Catherines Island, cosponsored by the American Museum of Natural History and the St. Catherines Island Foundation. Due to unforeseen circumstances, a few participants could not attend the meeting, but their contributions are included here anyway.

Previous Caldwell Conference publications have focused on methodological issues (e.g., Bishop, Rollins, and Thomas, 2011) or temporal themes (e.g., Deagan and Thomas, 2009; Thomas and Sanger, 2010). The papers in the present volume, however, are tied together by a geographic focus on the Georgia Bight, covering a broad range of temporal and methodological topics. We came to realize that this approach was worthwhile because both of us had recently worked on publications that required synthesizing and digesting the voluminous scholarly publications available on the Georgia Bight (including literature from both academic and contract archaeology). For Thomas, the three-volume Native American Landscapes of St. Catherines Island, Georgia (Thomas, 2008) pulled together a multiyear, interdisciplinary archaeological project conducted by the American Museum of Natural History and situated these results into the larger context of the Sea Islands coast to consider the implications of larger anthropological issues (emphasizing the changing interrelationships among human landscapes, subsistence practices, and the emergence of social inequality). For Thompson, the inspiration was his coauthored article with John Worth (published in the Journal of Archaeological Research) in which they presented a synthesis of Native American coastal adaptations in the American Southeast (Thompson and Worth, 2011). This article draws heavily on research results along the Georgia Bight, situated within broader theoretical and methodological contexts.

In these independent efforts, we both came to appreciate the growing corpus of new archaeological research on the Georgia Bight—considerably more material than could be incorporated into our respective publications. These research projects spanned multiple time periods (including Archaic, Woodland, Mississippian, and contact periods) and many incorporated specialized analyses (such as petrographic point counting, shallow geophysics, and so forth). Since we knew most of the major players involved in these ongoing projects and had visited and/or worked on many of these sites, we came to realize that a critical mass of new and innovative research warranted a volume specifically organized around the archaeology of the Georgia Bight.

We also recognized that most of the new research efforts built upon long-term scholarly legacies and inquiries in the region. Those readers already familiar with the archaeology of the Georgia Bight will recognize a number of familiar research themes, addressed in fresh and inventive perspectives. We hope that those new to this region will find parallels and draw inspiration from these studies, many of which have theoretical, methodological, cultural, and historical implications for broader anthropological understanding.

With these thoughts in mind, we pulled together our list of potential participants for this volume. We quickly realized that those conducting cutting-edge work in the Georgia Bight represented the full spectrum of the archaeological community, including museum, academic, student, and contract archaeologists. Despite the diversity in professional and theoretical backgrounds, temporal periods examined, and methodological approaches pursued, we readily identified several interrelated themes, which generated the organizational headings of this volume.

Contributions in Part I address analytical approaches to time, exchange, and site layout. David Hurst Thomas, Matthew C. Sanger, and Royce H. Hayes begin the section by examining the marine 14C reservoir correction (ΔR) for St. Catherines Island and extending this research to other areas of the Georgia coast. This work builds on the earlier derivation of the reservoir correction based on late 19th- and early 20th-century oyster shell samples recovered from oyster factories on St. Catherines Island (Thomas, 2008: chap. 13). Chapter 1 addresses the question of geographic variability in the ΔR from St. Catherines Island and whether the value changed through time. Thomas, Sanger, and Hayes present newly dated samples of prebomb marine invertebrates in order to refine the existing ΔR estimate. They conclude that ΔR remained relatively constant during the Late Holocene in the waters surrounding St. Catherines Island. They also found that the marine reservoir was stable throughout the seasons in this part of the Georgia Bight and did not vary appreciably in the areas sampled.

In chapter 2, Alexandra L. Parsons and Rochelle A. Marrinan examine and review the available faunal data from coastal Georgia and northeast coastal Florida. They consider a long temporal span, which begins at 3000 cal b.c. and ends at a.d. 1680. Their discussion includes samples from famous sites in the region, including McQueen Shell Ring, Sapelo Shell Ring complex, Kings Bay sites, Grand Shell Ring, and the Fountain of Youth site. Overall, they observe that the faunal records reflect similar subsistence strategies that persisted for millennia in this area, albeit with some temporal and geographic variation (see Colaninno, 2010). They also make recommendations for the future of faunal studies in the Georgia Bight.

In chapter 3, Ginessa J. Mahar argues that we should consider archaeological geophysics as a primary data source for interpreting the past. Building on the work of Kvamme (2003a) and Thompson et al. (2011), she presents a nuanced approach to the use of shallow geophysics in archaeology. Specifically, Mahar uses her own work at two Late Archaic shell rings on St. Catherines Island (both dating circa 3000 cal b.c. to 1000 cal b.c.) to argue that geophysics can supplement excavation data to provide a more holistic perspective.

Chapter 4, by Ann S. Cordell and Kathleen A. Deagan, examines paste variability and clay resource use among the 16th-century aboriginal populations at the Fountain of Youth (FOY) site in St. Augustine (Florida), established in 1565 by Pedro Menéndez de Avilés, which was the location of the first permanent European town in what was to become the United States. Deagan has excavated at FOY for a number of years, recovering a diverse ceramic assemblage, which includes St. Johns, San Marcos, and San Pedro wares. The early years of Spanish occupation in La Florida substantially altered aboriginal lifeways, with major shifts in demography and population density. Cordell and Deagan argue that technological ceramic analysis provides another way of monitoring such change through time. The paste of clay and sherd samples from FOY shows considerable variability and provides insight into the multiethnic population at the site, which included groups from other areas of the coast.

In chapter 5, Neill J. Wallis and Ann S. Cordell expand on the methodological insights of chapter 4 by comparing the results of petrographic analysis of thin sections from pottery and clays from southeast Georgia and northeast Florida with results of Instrumental Neutron Activation Analysis (INAA). They examine the famous Swift Creek pottery by distinguishing Early Swift Creek (circa cal a.d. 200–500) from Late Swift Creek (circa cal a.d. 500–800) ceramics. Swift Creek pottery has long fascinated archaeologists in the Deep South, mainly due to the intricately carved paddle-stamped designs on these vessels (e.g., Williams and Elliott, 1998; Pluckhahn, 2007; Wallis, 2008, 2011). It is notable that examples of paddle-stamped Swift Creek pottery, made with the same paddle, have been identified hundreds of kilometers apart. Investigating what kind of social interaction could lead to these widespread “paddle matches,” Wallis and Cordell use multiple techniques to examine the regional variation in clay and temper sources used to make Swift Creek pottery. These results suggest that whereas the vast majority of vessels studied were produced locally, some were transported from the Altamaha River to the St. Johns River area and deposited in burial mounds. Wallis and Cordell believe that this patterning reflects gift giving associated with marriage alliances between widespread descent groups.

Part II of this volume contains papers that model coastal landscapes from both environmental and social perspectives. Chester B. DePratter and Victor D. Thompson (chap. 6) reconstruct paleoshorelines using data collected by DePratter during his 1970s shoreline survey of islands along the Georgia Bight, augmented by modern site file data. The resulting maps demonstrate the nature of shoreline change over the past 4500 years, based largely on the northern Georgia ceramic sequence. These maps document the nature of environmental change on the Georgia coast, providing a point of departure for understanding the social implications of these changes.

In chapter 7, John A. Turck and Clark R. Alexander provide a complementary study with a more detailed examination of the local geomorphology and geology of the Georgia Bight. They present the results of recent vibracoring, sediment analysis, radiocarbon, and optically stimulated luminescence dating, arguing that these coastal landscapes have evolved in complex ways, rendering the holistic modeling and human utilization of these landforms problematic. That said, Turck and Alexander demonstrate how geoarchaeological techniques can generate a more nuanced understanding of human environmental interactions. For the most part, chapter 7 corroborates the previous archaeological dating of coastal landforms (e.g., DePratter and Thompson, chap. 6, this volume) and also the observation that humans utilized new landforms shortly after they formed (see Thompson, Turck, and DePratter, 2013).

In chapter 8, Matthew F. Napolitano considers the role of small islands along the central Georgia coast, building upon the recent surveys of marsh islands near Sapelo Island (Thompson and Turck, 2010). Napolitano surveyed Bull Island with a full coverage 20 m interval shovel test program, small scale testing, and specialized analysis of excavated materials (e.g., stable isotope analysis on shellfish). Napolitano’s research documented a 4000 year history of human articulate that compares favorably with the extensive surveys conducted by the American Museum of Natural History on nearby St. Catherines Island (Thomas, 2008). The Bull Island survey demonstrates the intensive and extensive use of the broader landscape of the Georgia Bight, demanding that archaeologists consider the relative importance that small islands and landforms play in coastal economies (see also Keegan et al., 2008, for a similar example from another region).

In chapter 9, Matthew C. Sanger presents the results of the Springfield Legacy archaeology survey of 425 acres on the central Georgia coastal mainland. Sanger combines traditional shovel testing with Light Detection and Ranging (LiDAR) mapping to investigate specific landforms and the associated human settlement pattern. In his chapter, Sanger provides detailed information on several different dimensions of environmental change, subsistence, and demographic shifts, concluding that this landscape is composed of multiple connections rather than impenetrable boundaries. The surveys by Sanger and Napolitano help generate broader perspectives on the nature of coastal settlement over vast temporal periods.

Chapter 10, by Thomas G. Whitley, is a GIS modeling of seasonality and potential caloric return rates for habitats and species across the Georgia Bight. Drawing on a theoretical framework grounded in human behavioral ecology, Whitley simultaneously develops a predictive model and reveals the variability in the coastal Georgia landscape. This heterogeneity, Whitley argues, allows for modeling of spatial value as predicted by caloric returns, generating insights into the exploitation of coastal landforms with significant implications for social control and exchange of these resources. The Whitley model provides archaeologists working on the Georgia Bight with a powerful tool for exploring past subsistence practices, settlement patterning, and concomitant social relations.

The chapters in Part III address site-specific studies of late prehistoric architecture and village layout on the Georgia Bight. A variety of archaeological surveys have demonstrated that the Irene phase (circa cal a.d. 1350 to a.d. 1565) saw the greatest increase in site density (and by extension, human population) than any prior period (see Crook, 1984; Thomas, 2008; Thompson and Turck, 2010; Napolitano, chap. 8, and Sanger, chap. 9, this volume). But relatively little is known about the domestic architecture and village structure of these populations. Current knowledge is based largely on the reanalysis of landmark WPA excavation at the Irene-type site 9Ch1 (Caldwell and McCann, 1941; Thompson, 2009), but important new evidence is emerging.

In chapter 11, Deborah A. Keene and Ervan G. Garrison present a detailed analysis of the remains of Irene phase domestic architecture from the Grove’s Creek site (9Ch71) located on Skidaway Island, Georgia. Long-term excavation at this site has nearly doubled the number of Irene phase houses investigated on the Georgia coast. Keene and Garrison compile the information for all of these known structures, which are compared and contrasted with ethnohistoric descriptions of similar architecture. While there are gross similarities among these structures, these investigators emphasize the considerable diversity in the shape, size, and construction of domestic architecture, likely due to functional variability.

In chapter 12, Ryan O. Sipe reports on his large-scale excavation at Redbird Creek village site (9Bn9), an Irene phase village with an associated mortuary context. This chapter illustrates the potential for preserved features and village layout in the sandy soils of the Georgia Bight. These new data provide an important contribution to the variation in community patterning on the coastal mainland, particularly when compared to research on the barrier islands on Irene and mission period village settlements (e.g., Crook, 1984, Saunders, 2000a, 2000b; Thomas, 2008).

Part IV addresses mission period archaeology of the Georgia Bight. While considerable archaeological research has addressed this time frame, particularly on St. Catherines Island (e.g., Thomas, 1987, 1993a, 2008; Larsen, 1990, 2001a, 2001b, 2002; Blair, Pendleton, and Francis, 2009), there is still much to learn. Many of the missions and their associated Native American villages remain undiscovered or are only vaguely referred to in the historic documents. To understand the nature of initial European contact along the Georgia Bight, we need a large sample of sites, complemented by more detailed, focused studies of mission period sites previously investigated.

In chapter 13, Richard W. Jefferies and Christopher R. Moore present evidence that the village site of Sapala and its associated mission of San Joseph de Sapala are located on the northwest side of Sapelo Island, Georgia. This important site was occupied by at least four formerly independent communities by a.d. 1684, reflecting the intensified conflict during this time period. Although definitive Spanish architecture has yet to be identified, the volume of European goods (e.g., military items, ceramics, etc.) dating to the mission period is unmatched elsewhere on Sapelo Island. Jefferies and Moore use their archaeological findings to discuss the nature of Native American–Spanish interaction.

In chapter 14, Elliot H. Blair discusses community organization at Mission Santa Catalina de Guale based on geophysical, geochemical, topographic, and subsurface survey data. He investigates the nature of household distribution in the pueblo portion of the mission site, contextualizing his results into a sophisticated theoretical framework that allows for a more nuanced evaluation than such data normally receive.

In chapter 15, Keith H. Ashley, Vicki L. Rolland, and Robert L. Thunen present new data on the Spanish Mission of San Buenaventura de Guadalquini. Drawing upon both ethnohistoric and archaeological evidence, they document its move from the northern Mocama frontier (contemporaries of the Guale of the central and northern Georgia coast) to northeast Florida. They also attempt to pinpoint the exact location of the original St. Simons Island mission (in Georgia). While the original location remains unknown, the relocated mission, forced to move due to threats from English-sponsored slave raids and French corsairs, is the subject of their ongoing archaeological investigations. The relocated mission, renamed Santa Cruz y San Buenaventura de Guadalquini, is known archaeologically as the Cedar Point site (8Du81) on Black Hammock Island (Florida). They compare their work at Guadalquini with other coastal missions in an attempt to understand the variations in material culture and social life at such sites.

Chapter 16, by Victor D. Thompson, John A. Turck, Amanda D. Roberts Thompson, and Chester B. DePratter, examines the Guale landscape and the nature of interaction with Spanish arrival. These authors specifically address the degree to which traditional land use practices of the Guale changed during the early contact period. They employ shoreline survey information over a large region of the Georgia coast, having also conducted both shovel test survey of specific islands and excavation data from one small back barrier island site. They conclude that, whereas the Guale continued extensive utilization of the coastal landscape during the mission period, this utilization was not as intense as that during the late prehistoric era. They suggest that despite the relatively intense debate regarding Guale settlement patterns, few have taken a perspective using regional scale site locational data. Such studies have implications for, and can lend insight into, the way the Guale experienced and mediated colonial entanglements.

Given the regional focus of the Caldwell VI conference, we invited two discussants to participate, and all contributors benefited from their perspectives on the presentations. Mark Williams, who is intimately familiar with coastal and uplands archaeology in Georgia, shared his comments on the past and future of the archaeology of the Georgia Bight during the conference. Scott M. Fitzpatrick, an archaeologist who has worked in island and coastal settings in both the Caribbean and the Pacific, offers his thoughts on the broader place of the Georgia Bight in terms of worldwide island and coastal archaeology in chapter 17.

A WORD ABOUT RADIOCARBON DATING

All radiocarbon evidence presented in this volume has been calibrated according to the protocols set out by Bishop et al. (2011). Specifically, we uphold the standards established by the journal Radiocarbon in their “Instructions for Authors” (promulgated 22 August, 2005, and updated 28 August, 2006). The standard reference on the calculations and terminology follows Stuiver and Polach (1977). Whenever possible, calibrated dates are reported using the latest available international calibration curve (currently INTCAL09 and MARINE9).

• Uncalibrated Ages: In this volume, “b.p.” is understood to signify “conventional radiocarbon years before a.d. 1950.”

• Calibrated Ages: The symbol “cal” is used to express calibrated radiocarbon ages (with “cal” understood as “calibrated,” not “calendar”). In this volume, authors are free to use either “cal b.p.” or “cal b.c./a.d.” (or both). Similarly, the use of 1σ and/or 2σ confidence intervals is left to the author’s discretion.

• Reservoir Correction: see discussion in Thomas, Sanger, and Hayes (chapter 1, this volume).

• Rounding Conventions: We employ the rounding conventions advocated by Stuiver and Polach (1977: 362).

ACKNOWLEDGMENTS

We express our sincere thanks to the Trustees of the St. Catherines Island and Edward John Noble foundations for their unstinting support of the Caldwell Conference series, cosponsored by the American Museum of Natural History and the St. Catherines Island Foundation and held on St. Catherines Island (Georgia). We are especially grateful to Ms. June Noble Gibson for her friendship, guidance, and willingness to stick with us over the decades. We are also grateful to Mr. Jeremy Smith (president, St. Catherines Island Foundation), Mr. Noble Smith (executive director, St. Catherines Island Foundation), Mr. David Smith (director, St. Catherines Island Foundation), and the late Mr. Bradford Smith (cochair, St. Catherines Island Foundation); each has made unique contributions to our archaeology program.

Special and sincere thanks go to Mr. Royce H. Hayes (superintendent of St. Catherines Island) who facilitated the Sixth Caldwell Conference in countless ways. We are likewise grateful to the members of the St. Catherines Island staff, past and present, who helped out in the hundreds of ways that made our archaeological investigations more productive (and more fun). In particular, we thank Ms. Jenifer Hilburn and Ms. Mary-Margaret Macgill for on-island assistance and support. We are also extremely grateful to the staff of the St. Catherines Island Archaeological Project: Mr. Elliot Blair, Ms. Rachel Cajigas, Ms. Elizabeth Cottrell, Ms. Christina Friberg, Ms. Ginessa Mahar, Mr. Matthew Napolitano, Ms. Lori Pendleton, Ms. Diana Rosenthal, Mr. Matthew Sanger, and Ms. Anna Semon; each made numerous behind-the-scenes contributions that made the Sixth Caldwell Conference and subsequent publication run so smoothly.

We thank Dr. Torben Rick, Dr. Christopher Rodning, and Dr. Thomas Pluckhahn for their thoughtful and critical reviews of the entire draft manuscript.

Ms. Hannah Cain took the photograph that is featured on the cover, which depicts Mr. Martin Walker, Mr. Matthew Sanger, and Ms. Elizabeth Drolet. We also thank Mr. Elliot Blair, Ms. Rachel Cajigas, Ms. Elizabeth Cottrell, Ms. Christina Friberg, Ms. Ginessa Mahar, Mr. Matthew Napolitano, Ms. Lori Pendleton, Ms. Diana Rosenthal, Mr. Matthew Sanger, and Ms. Anna Semon for assistance with the manuscript production. We acknowledge the important contributions of Ms. Brenda Jones and Dr. Mary Knight for their editorial efforts.

Finally, we dedicate this volume to Travis and Rose Collins for their long-term support of Thompson’s work along the Georgia coast and to the Edward John Noble and St. Catherines Island foundations for their support of Thomas’s research on St. Catherines Island.

PART I: ANALYTICAL APPROACHES TO TIME AND EXCHANGE

CHAPTER 1: REVISING THE 14C RESERVOIR CORRECTION FOR ST. CATHERINES ISLAND, GEORGIA

David Hurst Thomas, Matthew C. Sanger, and Royce H. Hayes[1]

Radiocarbon dating has long been important to archaeologists working on St. Catherines Island and, to date, more than 300 “cultural” 14C determinations have been processed on island samples (Thomas, 2008: table 13.4). The recently published Geoarchaeology of St. Catherines Island presents an additional 60 noncultural radiocarbon dates (Bishop, Rollins, and Thomas, 2011: appendix I; see also Thomas, 2008: chap. 29, table 29.1).

The vast majority of these radiocarbon determinations were processed on marine shell, and for good reason. Speaking specifically of St. Catherines Island, we have argued that shell samples tend to provide more reliable results than charcoal samples from the same context. Not only are shell samples vastly more abundant, but, unlike charcoal, Holocene-age marine shells are not subject to contamination by organic carbon from modern vegetation decay (thereby reducing the importance of chemical cleaning). Large shell fragments do not move as readily through the stratigraphic column and do not have the problem of rootlet contamination (a difficulty with charcoal samples). Excreted by short-lived organisms, these shells are more abundant than reliable charcoal samples found in most shell middens. With the advent of high-precision radiocarbon techniques emphasizing short-lived terrestrial organisms, our thinking has changed somewhat, but we still believe that 14C dating of marine shells will always be important for archaeological chronologies along the Georgia coast and elsewhere.

More than four decades ago, Joseph Caldwell recognized the importance of combining radiocarbon dating with ceramic analysis to establish the cultural chronology of the Georgia coast. In a paper presented at the Southeastern Archaeological Conference in October 1970, he reported 13 new radiocarbon dates from his excavations on St. Catherines Island (Caldwell, 1971). Aware of some potential problems relating to the radiocarbon dating of marine shells, Caldwell deliberately paired some charcoal and shell determinations. Assessing the results from his first two field seasons of research on the island, he concluded that “radiocarbon determinations made from oyster shell do not appear to differ significantly from determinations made from charred wood. In this connection, some of you will recall that a few years ago modern oyster shells from adjacent Sapelo Island collected in 1955 were run at the University of Michigan (M-614) and did not differ significantly from Michigan’s wood standard” (Caldwell, 1971: 1). But later in the same paper, Caldwell admitted his suspicion that “our shell determinations, while compatible with charred wood determinations, may be running slightly later.” He wisely reassured that “of course we shall continue to look for an oyster shell correction factor and other factors based on the available amount of radiocarbon in the biosphere at a particular time.”

A decade later, while reporting the results of new excavations at several Refuge/Deptford period burial mounds on St. Catherines Island, Thomas and Larsen (1979: 138) presented 29 additional radiocarbon dates, nearly one-quarter of them processed on marine shell. Although referencing potential “reservoir effects,” these investigators basically relied on Caldwell’s previous intuition and ignored the problem.

We now realize that assumption was wrong. A significant reservoir effect is clearly operating here because, relative to the atmosphere, ocean water is depleted in 14C, transmitting this deficiency to marine organisms. This means that the apparent radiocarbon ages of marine samples can be several hundred years older than contemporaneous atmospheric 14C samples. Dissolved inorganic carbon in the upper ocean is influenced by the exchange with both the atmosphere and the radiocarbon-depleted deep ocean, with a 14C content intermediate between the two (Broecker, Ewing, and Heezen, 1960; Broecker and Olson, 1961; Berger, Taylor, and Libby, 1966; Taylor, 1987: 34). Reservoir effects—the incorporation of ancient carbonates in living organisms—are today attributed primarily to upwelling, in which water from deeper ocean contexts is periodically brought upward and mixed with surface ocean water. Marine shell species can also be heavily influenced by the effects of estuaries, bayous, inland waterways, and bay environments. In such environments, living shell can also be seriously affected by the discharge of carbonate-rich freshwater, which causes variability in apparent ages of up to a millennium.

Clearly then, 14C dating of zooarchaeological marine shells continues to play a prominent role in understanding the cultural chronologies of St. Catherines Island (and elsewhere), and we must correct for the reservoir effects involved in these analyses. When dating marine materials, it is essential to separate the 14C of the ocean surface from that of atmospheric CO2. Regional patterning is controlled by diverse factors, including localized circulation patterns, the relative inflow off freshwater sources (presumably carrying older carbonates), spatial variations in upwelling, water mass mixing, and variable air–sea gas exchange. ΔR values can likewise vary in marine mollusc samples due to species, habitat, and/or substrate (Dye, 1994; Forman and Polyak, 1997; Hogg, Higham, and Dahm, 1998; Reimer and Reimer, 2001; Masteller, Thieler, and Horton, 2011). In areas where waters are continuously exchanged with open ocean water and vertically well mixed (with concentrated upwelling offshore), reservoir effects tend to increase. Estuarine processes and dilution by freshwater most likely reduce reservoir effects within tidal waters.

REDEFINING RESERVOIR EFFECTS ON ST. CATHERINES ISLAND

We began developing a local reservoir correction by dating a series of known-age prebomb (< a.d. 1950) molluscs curated in various museum collections (Thomas, 2008: chap. 13, 348–353). The initial sample consisted of nine molluscs, spanning several species and approximately 800 km of coastline, from Beaufort (North Carolina) to Cocoa Beach (Florida). Although relevant comparable values are still scarce (see Masteller, Thieler, and Horton, 2011, and Rick et al., 2011 for recent advances), the mean ΔR value for the Carolina–Florida subsample (106 ± 26 14C years) compared favorably with the other available regional average ΔR values (available at the time in the online Marine Reservoir Correction Database (http://calib.qub.ac.uk/marine/) for the Bahamas and Florida (36 ± 14 years), Long Island Sound, New York (165 ± 78), and the Gulf of Maine (38 ± 40 years). But because none of the available prebomb, known-age molluscs came from the Georgia coast, we needed a better way to create the modern control sample.

Knowing (1) that a commercial oyster industry had once flourished in the waters surrounding St. Catherines Island during the late 19th century and (2) this industry ceased operation during the 1920s, we reasoned that their massive spoil heaps on St. Catherines Island could provide a new, more specifically localized source of modern control samples. Specifically, because virtually all of the shells within these factory middens derived from Crassostrea virginica that were harvested between about 1900 and 1920, we anticipated that such known-age molluscs might be a useful addition to the reservoir-effect study (fig. 1.1). We estimated the age of harvest for each sample to be a.d. 1910 ± 10 years.

We processed numerous 14C determinations on Crassostrea virginica collected from the oyster boiling factories of St. Catherines Island and found that these “modern” oyster shells produced an extraordinarily negative mean ΔR value of –134 ± 26—one of the most extreme values yet recorded (Thomas, 2008: chap. 13, 357–259). It is clear that the intertidal species Crassostrea found on St. Catherines Island were sampling a different 14C reservoir than the surface mixed layer commonly assumed for such marine samples (perhaps due to intense wave action or exposure during low tide that caused atmospheric mixing in shallow and estuarine waters). When we applied this reservoir correction to 11 charcoal-marine shell pairs, we found that in each case the charcoal and marine shell dates overlap significantly, reinforcing the conclusion that the local reservoir factor satisfactorily resolves the discrepancy between atmospheric and marine samples on St. Catherines Island (Thomas, 2008: table 13.3, fig. 13.9).

Although the St. Catherines Island reservoir correction does indeed seem to “correct” marine dates to comparable ages derived from terrestrial samples, Thomas (2011a: 50–52) raised several potential problems with these procedures, and this paper attempts to address the most important of these.

Expanding the Sample

The extreme reservoir correction previously derived for St. Catherines Island might result from the positioning of the island relative to carbonate sources draining from the Piedmont. Of all the Georgia barrier islands, St. Catherines is currently farthest from a major river; neither Sapelo Sound to the south nor St. Catherines Sound to the north communicates directly with a major freshwater source. Rather, the Medway, South Newport, and Sapelo rivers are salt marsh estuaries situated north of St. Catherines, Sapelo, and Wolf islands, respectively, and are dominated by ebb tides, with very little freshwater inflow (Howard and Frey, 1975). Griffin and Henry (1984: 43) suggest that this isolation from major deltaic systems may account for the extreme rates of erosion observed on St. Catherines Island during the historic period. Even a cursory look at coastal geomorphology shows that St. Catherines Island lies near the southern extent of the destructive delta bulge built by the Savannah and Ogeechee rivers to the north. Perhaps this diminished freshwater sourcing reduces the number of carbonates entering the marine catchment. Further, the headwaters of the Ogeechee and Altamaha rivers extend far into the coastal plain and distributary systems that aggrade north of Ossabaw and Little St. Simons islands, respectively. Perhaps also, barrier island sources closer to these major rivers would contain a greater load of imported carbonates, thereby making their apparent age more extreme (and, of course, requiring a different reservoir correction).

Thomas (2011a: 51) hypothesized that distance to major deltaic systems might influence the reservoir effect: the closer to the major freshwater source, the greater the carbonate load reflected in the ΔR. Recent research in the mid-Atlantic has further reinforced this hypothesis as ΔR values were positively affected by proximity to freshwater sources (Masteller, Thieler, and Horton, 2011, and Rick et al., 2011). To test the hypothesis of lateral, facieslike variability, we expanded our small-scale sampling programs on late 19th- and early 20th-century oyster factories along the Georgia Bight. The attempt has been to locate known-age oyster samples and derive independent ΔR values to compare with the St. Catherines Island results (see table 1.1).

Here, we report the results from reservoir correction experiments at five additional oyster factories located along the central Georgia Bight (fig. 1.2).

South End Boiler, St. Catherines Island: Previous research on the St. Catherines Island reservoir correction sampled three separate oyster factories (fig. 1.1, see also Thomas, 2008: chap. 13). The results from King New Ground Field and Hoke’s Dock boilers proved to be satisfactory. But earlier work at the South End yielded mixed results because three of the four samples produced 14C determinations that were a millennium too old (clearly reflecting the use of ancient archaeological middens in constructing the causeway at South End).

In the winter of 2009, Hayes collected three additional samples from the South End boiler. Careful to collect only shells from the spoil pile directly associated with the boiler, Hayes’s new samples produced results entirely consistent with early 20th-century oyster collection, and these new dates appear in table 1.1.

Coffin Oyster Boiler, Sapelo Island: Working with Buddy Sullivan (former manager, Sapelo Island National Estuarine Research Reserve), we attempted to sample oysters from the cannery operated by island owner Howard Coffin about 1920–1930, located on Barn Creek, along the southwest side of Sapelo Island (fig. 1.2). Mr. Sullivan noted that whereas only minimal shell residue remained near the boiler itself (fig. 1.3), there was sufficient shell along the eroding bank and three samples were submitted for radiocarbon dating. As indicated on table 1.1, these three 14C dates are clearly a millennium too old and we conclude (per our earlier experience at the South End boiler on St. Catherines Island) that we had inadvertently sampled an ancient archaeological midden, and these too-old dates are not helpful in computing the reservoir correction operating in the waters surrounding Sapelo Island. We now suspect that Mr. Coffin was using the oyster shell debris created by his oyster cannery to improve the roads of Sapelo Island, meaning that an oyster factory-related midden did not occur near the boiler.

Shell Bluff Canning Company, Valona: Sullivan also recommended that we sample the shell deposits at the commercial fishing village of Valona, located on a bend in Shellbluff Creek, about 10 mi north of Darien, Georgia (fig. 1.2). Serious commercial harvesting of oysters in McIntosh County began in the 1890s with the opening of the Valona factory (fig. 1.4), which continued operations into the very first part of the 20th century (Sullivan, 2000a: 99; see also Sullivan, 2008: 15); this site later became the Durant shrimp docks (and subsequently the King Seafood docks). This purely saltwater locality was important for the reservoir correction study because it contained the oldest commercial oyster shell deposits in McIntosh County. When Hayes and Thomas visited Valona in May 2009, they found ample shell deposits on the banks of the creek. The single, highly satisfactory AMS date was processed from the Valona shell deposits (table 1.1).

Yellow Bluff Fishing Camp, Colonel’s Island: In his history of Liberty County, Robert Long Groover (1987) notes that the Yellow Bluff fishing camp was established in 1924, along with an associated oyster factory (fig. 1.2; see also Devendorf, 2009: 39). Assisted by Jeff Woods, Hayes and Thomas collected an oyster sample from the spoil pile associated with the former oyster boiler.

Bluff Creek, Colonel’s Island: Assisted by Jeff Woods, Hayes, and Thomas collected a shell sample from the oyster factory that once operated here, adjacent to the property of Jack Waters (fig. 1.2); we assume that this oyster factory is contemporary with those operated by Augustus Oemler on St. Catherines Island (see table 1.1).

Sunbury: Assisted by Jeff Woods, Hayes, and Thomas collected a shell sample from the oyster factory spoils in downtown Sunbury (fig. 1.2). We have no specific information about the dates of the Sunbury factory, but we assume that it is contemporaneous with those operated by Augustus Oemler on St. Catherines Island (see table 1.1).

Recomputing the Reservoir Age and ΔR

We have now generated an expanded control sample of prebomb molluscs that have been dated by 16 independent 14C determinations on Crassostrea virginica samples from St. Catherines Island and surrounding waters (table 1.1). Following Reimer and Reimer (2001: 461), we will compute a correction for the regional variation from marine reservoir age (ΔR), then calibrate using the standard marine calibration curve (originally proposed by Stuiver, Pearson, and Braziunas, 1986 [and revised in Stuiver et al., 1998], per procedures outlined in Stuiver and Braziunas, 1993). Table 1.1 employs the following definitions, adopted from the Marine Reservoir Correction Database website (http://www.calib.org/marine; see also Reimer and Reimer, 2001):

14C age b.p. = conventional radiocarbon age (half-life = 5568 years; corrected for isotopic fractionation) as defined by Stuiver and Polach (1977)

Reservoir age = measured marine 14C–atmospheric 14C at time t (as defined by Stuiver, Pearson, and Braziunas, 1986)

ΔR = difference between the regional and global marine 14C = measured marine 14C – marine model 14C age at time t.

These terms and conventions, employed in table 1.1 are discussed in considerable detail elsewhere (Thomas, 2008: chap. 13); the previous estimates have been updated (below) using the newest available atmospheric and marine datasets.

The Measured 14C Age: We must first derive a measured 14C estimate for each modern, prebomb marine sample. Such conventional age estimates take the apparent 14C age normalized to a Δ13C value of –25% of the PDB standard (Stuiver and Polach, 1977).

The Atmospheric 14C Age: The atmospheric age is derived from the IntCal04 calibration dataset (Reimer et al., 2004).

The Global Marine 14C Age: The global marine 14C age is available from the decadal marine calibration dataset, Marine04 (Hughen et al., 2004).

The Reservoir Age: The reservoir age, R, is the difference between the measured marine 14C age and the atmospheric 14C for the year of collection for each modern sample. The error term in this case is based on counting statistics and the uncertainty in the marine calibration dataset (Reimer and McCormac, 2002: 163).

As before, the error term is given by the square root of the summed variances. Following current 14C protocols, we compute the central tendency of ΔR values as the weighted mean of the individual ΔR values (e.g., Reimer and Reimer, 2001; Reimer and McCormac, 2002).[2]Additionally, following Reimer and Reimer (2001: 461) and Reimer and Reimer (2001: 131), we define the uncertainty around the regional mean ΔR as the maximum of (1) the standard deviation (the sigma mean based on the reported error in the conventional sample 14C shell ages) and (2) the scatter sigma (the square root of the variance divided by the number of samples).

For the N = 16 samples listed in table 1.1, we calculate the regional ΔR mean to be –119 14C years b.p. The sigma mean for this sample is 15.5 14C years b.p. and the sigma scatter is 16.0 14C years b.p.; we will employ the larger value to estimate the error of the regional ΔR mean.

To summarize: the new sample of 16 prebomb, known-age samples of Crassostrea virginica is now computed to be –119 ± 16 14C years b.p. The revised mean and error term are slightly less than the previously estimated St. Catherines Island reservoir correction of –134 ± 26 14C years b.p. (as derived in Thomas, 2008: chap. 13).

As a practical matter, these revised results make virtually no difference in the actual computation using the St. Catherines Island reservoir correction (ΔR), as is graphically evident in figure 1.5. Beta-242427, for instance, is a Mercenaria mercenaria sample from Back Creek Village (26Li207), a late prehistoric site on St. Catherines Island. The uncorrected 14C age is 740 ± 40, which can be readily converted into two-sigma ranges using the old and revised ΔR from St. Catherines Island:

Previous St. C. Island ΔR Revised St. C. Island ΔR

(–134 ± 26) (–119 ± 16)

cal a.d. 1350–1540 cal a.d. 1400–1540

Figure 1.5 also plots the differences in ΔR for UGA-64, a date on Crassostrea america from Stage II construction at Johns Mound, a St. Catherines period burial mound (Thomas and Larsen, 1982). The uncorrected 14C age is 1090 ± 60, which is readily converted into two-sigma ranges using the old and revised ΔR from St. Catherines Island:

Previous St. C. Island ΔR Revised St. C. Island ΔR

(–134 ± 26) (–119 ± 16)

cal a.d. 1050–1290 cal a.d. 1060–1300

Finally, figure 1.5 plots the differences in ΔR for Beta-251769, a Mercenaria sample from the McQueen Shell Ring (Sanger and Thomas, 2010: table 3.1). The adjusted 14C age is 3830 ± 40:

Previous St. C. Island ΔR Revised St. C. Island ΔR

(–134 ± 26) (–119 ± 16)

2150–1870 cal b.c. 2130–1870 cal b.c.

In all cases, the changes in calibration between previous and revised ΔR values for St. Catherines Island are minimal.

It is important to note that the revised St. Catherines Island reservoir correction both refines and expands the usefulness of this ΔR value. The negative mean ΔR values found on St. Catherines Island and vicinity remain some of the most extreme values to be recorded anywhere in the world, differing considerably from those ΔR estimates from elsewhere along the Eastern Seaboard (Paula Reimer, personal commun.; Masteller, Thieler, and Horton, 2011, and Rick et al., 2011). Given the critical importance in melding marine and terrestrial 14C along this 1000-mile-long expanse, it is clear that much work remains to be done. The only comparable research was recently conducted along the Chesapeake Bay and Middle Atlantic coast (Masteller, Thieler, and Horton 2011; Rick et al., 2011). This recent increase in research into the local variability of marine reservoir corrections is heartening as it suggests that we are getting closer to building a database that will facilitate cross-regional comparability. This research also highlights the need for further microregional studies as ΔR values varied by more than 250 years between samples drawn from less than 100 mi of one another (Masteller, Thieler, and Horton, 2011).

POTENTIAL ISSUES OF OCEANIC UPWELLING

Reservoir effects—the incorporation of ancient carbonates in living organisms—are today attributed primarily to upwelling, meaning that water from deeper ocean contexts is periodically brought upward and mixed with surface ocean water. When such upwelling is uncommonly high, the apparent 14C age of water can be in excess of 1000 years, in part because the slow mixing of deep ocean waters leaves the global marine radiocarbon reservoir depleted of 14C relative to the atmosphere. Even within somewhat restricted areas, localized upwelling can induce variations up to the equivalent of 200–300 years in the reservoir effects. Marine shell species can also be heavily influenced by the effects of estuaries, bayous, inland waterways, and bay environments (Broecker and Olson, 1961). In such environments, living shell can also be seriously affected by the discharge of carbonate-rich freshwater, which causes variability in apparent ages of up to a millennium (Berger, Taylor, and Libby, 1966).

To date marine materials, it is essential to separate the 14C of the ocean surface from that of atmospheric CO2. Regional patterns of ΔR are controlled by diverse factors, including localized circulation patterns, the relative inflow off freshwater sources (presumably carrying older carbonates), spatial variations in upwelling, water mass mixing, and variable air–sea gas exchange. ΔR values can likewise vary in marine mollusc samples due to species, habitat, and/or substrate (Dye, 1994; Forman and Polyak, 1997; Hogg, Higham, and Dahm, 1998; Reimer and Reimer, 2001). In areas where waters are continuously exchanged with open ocean water and vertically well mixed (with concentrated upwelling offshore), reservoir effects tend to increase. Estuarine processes and dilution by fresh water most likely reduce reservoir effects within tidal waters.

Kennett and Culleton (2012) demonstrate how annual growth increment studies of hard clams (Mercenaria mercenaria) can today be integrated into a program of high-precision AMS 14C dating (e.g., O’Brien and Thomas, 2008; Quitmyer and Jones, 2012). These studies are ongoing, and the specifics of wiggle-matching and Bayesian modeling are beyond the present scope; but recent radiocarbon results from this approach are relevant to our consideration of reservoir effects on St. Catherines Island and elsewhere.

In the previous consideration of the reservoir offset on St. Catherines Island, Thomas (2008: chap. 13) assumed marine upwelling to be minimal, reflecting a greater than average mixing of atmospheric carbon compared to the global marine model age. But as Kennett and Culleton (2012) have emphasized, this assumption requires testing and we can now do this.

Seasonal Variability in ΔR

Based on an exhaustive study of hard clams recovered from the McQueen Shell Ring (Sanger and Thomas, 2010), Quitmyer and Jones (2012) determined that the Mercenaria valves recovered from the “clam floor” feature were intensively harvested during a very narrow period of time during winter and spring seasons. They further determined through age-based analysis that the zooarchaeological population represented at the McQueen Shell Ring was dominated by individuals between two and six years of age. In contrast to modern baseline studies, this zooarchaeological collection was nearly devoid of hard clams living longer than six years.

In a recent experiment with important implications for our understanding of the reservoir correction on St. Catherines Island, Quitmyer selected the single oldest individual analyzed in the “clam floor” zooarchaeological assemblage from the McQueen Shell Ring. This eight-year-old individual valve, previously sectioned for annual incremental analysis, was submitted to the Archaeometry Laboratory at the University of Oregon, where Douglas Kennett and Brendan Culleton removed microdrilled samples for AMS dating at the Keck Carbon Cycle AMS Facility, Earth System Science Department, University of California, Irvine. Five AMS dates were processed on this single Mercenaria valve—three from the opaque (winter) incremental bands and two from the translucent (spring, summer, fall) growth ring—as indicated in figure 1.6 and table 1.2.

Specifically with respect to the issues surrounding the variability of ΔR—within a single year, through deeper time, and across space—several points emerged from this pilot study. For one thing, the sequential, high-precision dating of this single Mercenaria valve makes it crystal clear that the marine reservoir surrounding St. Catherines Island is extraordinarily stable on a season-to-season basis. This portion of the Georgia Bight is totally lacking in the radical fluctuations within the annual cycle caused by varying supplies of old carbon resulting from upwelling, as noted elsewhere in the world (e.g., Kennett et al., 1997; Culleton et al., 2006). We have previously assumed this to be true, but this is the first empirical evidence that effectively tests this important assumption.

DOES ΔR REMAIN CONSTANT THROUGH TIME IN THE GEORGIA BIGHT?

We initially assumed that the global reservoir 14C age of the ocean’s surface water has remained stable through time on St. Catherines Island (and there is some support for this assumption; e.g., Reimer and Reimer, 2001). But other studies have found that local marine ΔR values have fluctuated through time, due primarily to changing patterns of ocean circulation or regional upwelling in which deeper, older water may cause ΔR to vary temporally (e.g., Ingram and Southon, 1996; Kennett et al., 1997; Deo, Stone, and Stein, 2004).

Recent research by Timothy Chowns and his colleagues suggests another mechanism through which differential carbon uptake and ΔR shifts might have occurred in the waters surrounding St. Catherines Island. Chowns (2002) and Chowns et al. (2008) argue that rising sea levels over the last few thousand years have caused a number of inlets along the Georgia coast to be become straighter. This change in drainage pattern has caused some inlets (such as St. Simons Sound, Sapelo Sound, and Ossabaw Sound) to become broader, while others have narrowed (viz. St. Andrews and St. Catherines sounds; see also Chowns, 2011). Chowns et al. (2008) have demonstrated this “jumping inlet” pattern of stream capture for the Brunswick River, which, prior to about 1480 b.p., entered the Atlantic Ocean south of Jekyll Island. But rising sea level “encouraged the river” to follow a more direct route and empty instead to the north of Jekyll. If similar patterns of relocation hold further to the north, then redirection of the Altamaha and Ogeechee rivers could significantly change the distribution of ancient carbonates from the various catchments on the Piedmont. With these possibilities in mind, we have been seeking ways of monitoring ΔR shifts in the archaeological sites of St. Catherines Island.

One productive avenue comes from the McQueen Shell Ring study discussed in the previous section. As indicated in table 1.2, the five AMS dates processed on the same Mercenaria valve are statistically the same (t = 7.8; χ20.05 = 9.49), with a pooled mean age of 3889 ± 6.3 14C years. Applying the revised St. Catherines Island reservoir correction (–119 ± 16 14C years), the pooled mean Mercenaria age converts to 2150–1980 cal b.c. Several contemporary terrestrial samples are available from the correlative stratum at the McQueen Shell Ring, but the most precise comparison comes from two recent AMS dates on hickory nut fragments (cited in Sanger and Thomas, 2010: table 3.1; see also table 1.4, this chapter). Figure 1.6 demonstrates how the revised St. Catherines Island reservoir correction shows the near-complete overlap and agreement in the probability distributions of the composite marine mean and the two terrestrial samples.

A second, related point also emerges from figure 1.6. Despite the close agreement between the marine and terrestrial dates, they are statistically different from one another (t = 34.63038; χ20.05 = 5.99). This counterintuitive result underscores a major point made recently by Kennett and Culleton (2012):

Radiocarbon dates with large analytical error reflect poor precision, but also undermine accuracy by increasing the range of accurate calendar ages that could produce the measure age. This compromises our ability to determine if two sites with seasonality data are contemporary or not ... put simply, low precision dates are more likely to appear contemporaneous, even with a generally robust statistical test, than high-precision dates [emphasis added].

This is precisely what happened in figure 1.6: despite the overlapping and virtually identical probability distributions, the precise error terms involved in both the composite marine and two terrestrial samples make it extremely difficult to establish statistical contemporaneity. Such high-precision comparisons will become increasingly important as we pursue multiscalar approaches to site contemporaneity and seasonality.

We can also approach the issue of potentially fluctuating ΔR values by examining paired terrestrial and marine samples from secure archaeological contexts. One problem with the previous “test” was that most of the 11 paired samples (Thomas, 2008: chap. 13) derived almost entirely from late prehistoric (Irene) contexts, with only two of the pairs coming from pre-Irene contexts; none of the 14C ages were older than 2000 14C yr b.p. (Thomas, 2008: table 13.1).[3]To test the proposition that ΔR values might shift through time, we have been systematically collecting paired charcoal-marine shell dates during our more recent excavations, including the two contemporary Late Archaic shell rings on St. Catherines Island—the McQueen Shell Ring (9Li1648) and St. Catherines Shell Ring (9Li231)—two sites that were occupied approximately 2500–2000 cal b.c. (Sanger and Thomas, 2010). In the case studies below, we will employ a simple simulation method to seek the effects of changing ΔR values by examining 15 different marine-terrestrial pairs from our St. Catherines Island research (table 1.3).

The selection criteria were fairly straightforward. Based on archaeological provenience information, we decided whether it was reasonable that two marine-terrestrial samples could be assumed to have shared behavior contemporaneity; this is entirely a subjective determination. Then, once the radiocarbon dates were processed, we returned to these paired dates; if the two samples returned “approximately contemporary” 14C results, we retained the pair for additional analysis. As a practical matter, we usually required that the mean difference in 14C ages be less than two or three centuries (although we did include a couple of more extreme cases on table 1.4, for comparison purposes).

Clearly, this selection process is problematic, arbitrary, and prone to error. But as a practical matter, we thought it better to include a broader range of dated pairs than to hyperselect only a handful of potential pairs (a process that could seriously bias the outcome). And selectivity aside, we must emphasize again the intuitive nature of any assumption that two samples are in fact behaviorally contemporaneous.

The Paired Samples from St. Catherines Island: Late Archaic Contexts

Pair A1: McQueen Shell Ring (9Li648): Table 1.3 compares a charred organic sample (Beta-251761, processed by AMS) from N243 E233 (4.3–4.2 m) with a Mercenaria mercenaria sample (Beta-251769) from the same excavation unit within 20 cm of each other, processed by conventional radiometric analysis. The mean age of the clam sample is 110 14C years older than the terrestrial sample (fig. 1.7).

The calibration issue can be approached in two rather different ways. Employing the IntCal09 dataset, we find that the terrestrial sample (Beta-251761) converts to an age estimate of 2280–1980 cal b.c. Using the revised St. Catherines Island ΔR value derived above (–119 ± 16) and the Marine09 dataset, the hard clam radiocarbon date calibrates to 2130–1870 cal b.c. By using the revised St. Catherines Island ΔR, the two dates largely overlap one another.

These results certainly confirm the application of the revised St. Catherines Island reservoir correction on paired samples nearly 4000 years old. But in this section, we are questioning whether this reservoir correction has remained unchanged over this time span, and another approach seems warranted as well.

Figure 1.8 shows a simple simulation designed to determine goodness-of-fit across a range of reservoir correction values. The bottom curve arrays the probability profile for the terrestrial sample discussed above (Beta-251761). The upper seven probability profiles array the Mercenaria sample (Beta-251769), calibrated with a series of reservoir corrections at five-decade increments ranging from 50 ± 25 14C years to –250 ± 25 14C years.

Whereas the revised St. Catherines reservoir correction (–119 ± 16 14C years) effectively calibrates the marine sample relative to its terrestrial match, figure 1.6 clearly demonstrates that the best calibration fit for pair A1 derives from a simulated reservoir correction of –225 ± 25 14C years.

Pair A2: McQueen Shell Ring (9Li648): Table 1.3 compares the same charred organic sample in pair A1 (Beta-251761) with a different Mercenaria mercenaria sample (Beta-251762) from the same provenience, both processed by AMS dating. The mean age of the clam sample is 100 14C years older than the terrestrial sample.

The terrestrial sample (Beta-251761) converts to an age estimate of 2280–1980 cal b.c. Applying the revised St. Catherines Island reservoir correction to the Marine09 dataset, Beta-251762 converts to 2140–1820 cal b.c. As with the first pair of radiocarbon results, the application of the revised St. Catherines Island ΔR generally brings these two dates into agreement.

Whereas the revised St. Catherines reservoir correction (–119 ± 16 14C years) effectively calibrates the marine sample relative to its terrestrial match, the simulated goodness-of-fit across a range of reservoir correction values demonstrates that the best fit for pair A2 is a reservoir correction of –225 ± 25 14C years.

Pair B: Mcqueen Shell Ring (9Li648): Table 1.3 compares a charred organic sample from Feature 38 NE (Beta-258561) with a correlative Mercenaria mercenaria sample (Beta-258562) from the same provenience, both processed by AMS dating. The mean age of the clam sample is 100 14C years older than the terrestrial sample.

The terrestrial sample converts to an age estimate of 2210–1950 cal b.c.

Applying the revised St. Catherines Island reservoir correction to the Marine09 dataset, Beta-251762 converts to 2120–1850 cal b.c.

These results echo the findings for pairs A1 and A2: Although the revised St. Catherines reservoir correction (–119 ± 16 14C years) effectively calibrates the marine sample relative to its terrestrial match, the simulated goodness-of-fit across a range of reservoir correction values demonstrates that the best fit for pair A2 is a reservoir correction of -225 ± 25 14C years.

Pair C: McQueen Shell Ring (9Li648): Table 1.3 compares a charred organic sample from N243 E233, 4.4–4.3 m (Beta-251767) with a correlative Mercenaria mercenaria sample (Beta-251768) from the same provenience, both processed by AMS dating. The mean age of the clam sample is 230 14C years older than the terrestrial sample.

The terrestrial sample converts to an age estimate of 2200–1950 cal b.c. Applying the revised St. Catherines Island reservoir correction to the Marine09 dataset, Beta-251768 converts to 2240–1960 cal b.c. The application of the St. Catherines Island ΔR brings these two dates into near perfect concordance. The simulated goodness-of-fit suggests that the best calibration fit for pair C is a reservoir correction of –75 ± 25 14C years.

Pair D1: McQueen Shell Ring (9Li648): Table 1.3 compares a charred organic sample from N272 E200, 5.1–5.0 m (Beta-251766), processed by AMS dating with a correlative Mercenaria mercenaria sample (Beta-251765) from the same provenience, processed by conventional radiometric dating. The mean age of the clam sample is 190 14C years older than the terrestrial sample.

The terrestrial sample converts to an age estimate of 2440–2060 cal b.c. Applying the revised St. Catherines Island reservoir correction to the Marine09 dataset, Beta-251765 converts to 2390–2040 cal b.c. Again, the application of the revised St. Catherines reservoir correction (–119 ± 16 14C years) calibrates the dates to near perfect concordance. The simulated goodness-of-fit across a range of possible reservoir correction values indicates that the best calibration fit for pair D1 derives from a reservoir correction of –150 ± 25 14C years. In this case, the St. Catherines reservoir correction undercorrected the marine result.

Pair D2: McQueen Shell Ring (9Li648): Table 1.3 compares a terrestrial sample from N272 E200 5.3–5.2 m (Beta-251764), with the same correlative Mercenaria mercenaria sample employed in D1 (Beta-251765), processed by AMS dating. The mean age of the clam sample is 280 14C years older than the terrestrial sample.

The terrestrial sample converts to an age estimate of 2210–1980 cal b.c. As before, Beta-251765 converts to 2390–2040 cal b.c., bringing the two dates significantly closer together than they would be without the revised St. Catherines Island reservoir correction.

The simulated goodness-of-fit across a range of possible reservoir correction values indicates that the best calibration fit for pair D2 derives from a reservoir correction of –50 ± 25 14C years. In this case, the St. Catherines reservoir correction overcorrected the marine result.

Pair E1: St. Catherines Shell Ring (9Li231): We have derived three possible pairs of samples from a single provenience at the St. Catherines Shell Ring. Table 1.3 compares a charred organic sample from N771 E819, 2.39–2.3 m (Beta-238337), processed by AMS dating with a correlative Mercenaria mercenaria sample (Beta-238336) from the same provenience, processed by conventional radiometric dating. The mean age of the clam sample is 530 14C years older than the terrestrial sample.

The terrestrial sample converts to an age estimate of 2460–2210 cal b.c. Applying the revised St. Catherines Island reservoir correction to the Marine04 dataset, Beta-238336 converts to 2890–2570 cal b.c.

The revised St. Catherines reservoir correction (–119 ± 16 14C years) does not calibrate the marine sample relative to the terrestrial match. The simulated goodness-of-fit across a range of possible reservoir correction values indicates that the best calibration fit for pair E1 would require a reservoir correction of roughly 100 ± 25 14C years. Given the disparity in mean 14C age between these two samples, it’s a stretch to believe that pair E1 is behaviorally contemporary.

Pair E2: St. Catherines Shell Ring (9Li231): This is the final possible pair of samples from this provenience. Table 1.3 compares a direct date on organics contained within a fiber-tempered sherd from N771 E819, 2.39–2.30 m (Beta-273291), processed by AMS dating with a correlative Mercenaria mercenaria sample (Beta-238336) from the same provenience, processed by conventional radiometric dating. The mean age of the clam sample is 410 14C years older than the terrestrial sample.

The terrestrial sample converts to an age estimate of 2580–2350 cal b.c. Applying the revised St. Catherines Island reservoir correction to the Marine09 dataset, Beta-238336 converts to 2890–2570 cal b.c.; these calibrated estimates barely overlap with one another. Although there is a wide disparity in mean age of these two samples, the simulated goodness-of-fit shows the best calibration fit for pair E3 would require a reservoir correction of roughly 50 ± 25 14C years. It seems likely that our attempt to directly date the fiber-tempered sherd failed and we instead dated more recent materials that do not accurately reflect the actual usage and deposition of the sherd.

The Paired Samples from St. Catherines Island: Late Prehistoric Contexts

Pair F: Back Creek Village (9Li207): Table 1.3 compares a charred maize sample from N493 E495, 49.75–49.65 cm (Beta-249873) with a correlative Mercenaria mercenaria sample (Beta-242426; both processed by AMS dating). The mean age of the clam sample is 290 14C years older than the maize sample (fig. 1.9).

The maize sample converts to an age estimate of cal a.d. 1410–1620 and the hard clam sample converts to cal a.d. 1380–1540, using the revised St. Catherines Island reservoir correction. As with many of the other samples, the application of the revised St. Catherines Island reservoir correction brings the two dates into near concordance.

The simulated goodness-of-fit across a range of possible reservoir correction values indicates that the best calibration fit for pair F requires a reservoir correction of –175 ± 25 14C years.

Pair G: Back Creek Village (9Li207): Table 1.3 compares a charred maize sample from test pit IV, 48.78–48.69 cm (Beta-249874) with a correlative Mercenaria mercenaria sample (Beta-242421; both processed by AMS dating). The mean age of the clam sample is 350 14C years older than the maize sample. The maize sample converts to an age estimate of cal a.d. 1430–1630 and the hard clam sample converts to cal a.d. 1380–1530, using the revised St. Catherines Island reservoir correction. These calibrated estimates are nearly identical to one another.

The simulated goodness-of-fit across a range of possible reservoir correction values indicates that the best calibration fit for pair G requires a reservoir correction of –75 ± 25 14C years to close the gap.

Pair H1: Marys Mound (9Li20): Table 1.3 compares a charred maize sample from burial 2 (Beta-225470), processed by AMS dating with a correlative Mercenaria mercenaria sample from Stage II construction (UGA-1685, processed by conventional radiometric dating). The mean age of the oyster shell sample is 60 14C years older than the maize sample.

The human bone sample converts to an age estimate of cal a.d. 900–1150 and the oyster sample converts to cal a.d. 1060–1300, using the revised St. Catherines Island reservoir correction.

Given the broad age spread between the mean dates, it seems unlikely that these two samples date contemporaneous events. But if they do, then the revised St. Catherines reservoir correction far undercalibrates the marine sample relative to its terrestrial match (at a level of 0.05 statistical significance). The simulated goodness-of-fit across a range of possible reservoir correction values indicates that the best calibration fit for pair H1 requires a reservoir correction of –300 ± 25 14C years to close the gap.

Pair H2: Marys Mound (9Li20): Table 1.3 compares a charred maize sample from burial 6 (Beta-225473), processed by AMS dating with the same correlative Mercenaria mercenaria sample used in pair H1 (UGA-1685). The mean age of the oyster shell sample is 120 14C years older than the maize sample.

The human bone sample converts to an age estimate of cal a.d. 1030–1210 and, as before, the oyster sample converts to cal a.d. 1060–1300, using the revised St. Catherines Island reservoir correction. These calibrated estimates are relatively similar to one another, although they are not in perfect concordance.

The simulated goodness-of-fit across a range of possible reservoir correction values indicates that the best calibration fit for pair H2 requires a reservoir correction of –200 ± 25 14C years to close the gap.

Pair I1: Johns Mound (9Li18): Table 1.3 compares a human bone sample from burial 10 (Beta-225475), processed by AMS dating with a correlative Crassostrea sample from Stage II mound construction (UGA-64). The mean age of the oyster shell sample is 120 14C years older than the human bone sample.

The bone sample converts to an age estimate of cal a.d. 890–1020 and the oyster sample converts to cal a.d. 980–1240, using the revised St. Catherines Island reservoir correction. These calibrated estimates largely overlap one another, although the best calibration fit for pair I1 requires a reservoir correction of –250 ± 25 14C years.

Pair I2: Johns Mound (9Li18): Table 1.3 compares a human bone sample from charcoal found in the Central Pit (UGA-61) and the correlative Crassostrea sample (employed in pair I1) from Stage II mound construction (UGA-64), both processed by conventional radiometric methods. The mean age of the oyster shell sample is 100 14C years older than the Central Pit charcoal.

The charcoal sample converts to an age estimate of cal a.d. 1020–1250 and the oyster sample converts to cal a.d. 980–1240, using the revised St. Catherines Island reservoir correction. These calibrated estimates are nearly identical. The simulated goodness-of-fit across a range of possible reservoir correction values indicates that the best calibration fit for pair I2 requires a reservoir correction of –100 ± 25 14C years to close the gap.

Pair J: Seaside Mound I (9Li26): Table 1.3 compares a charcoal sample from the Central Tomb (UGA-112) with a correlative Crassostrea sample from Feature 15 (UGA-1826). The mean age of the oyster shell sample is 200 14C years older than the charcoal sample.

UGA-112 converts to an age estimate of cal a.d. 390–870 and the oyster sample converts to cal a.d. 515–780, using the revised St. Catherines Island reservoir correction. These calibrated estimates are almost identical. The simulated goodness-of-fit across a range of possible reservoir correction values indicates that the best calibration fit for pair J is –150 ± 25 14C years, a value quite close to the revised St. Catherines ΔR.

DISCUSSION

This section addressed the question of whether ΔR remained relatively constant in the waters surrounding St. Catherines Island during the late Holocene. The most satisfying results came from the transect of five 14C dates across the seasonal increments accumulated on an eight-year-old Mercenaria from the McQueen Shell Ring. The fact that all five radiocarbon samples, with a pooled mean of 2150–1980 cal b.c., generated an extremely close fit with two closely associated hickory nut fragments is strong evidence for continuity in ΔR values across the last 4000 years. But, importantly, the marine and terrestrial dates were not indistinguishable, underscoring the point that increased precision in the radiocarbon dating process carries with it the need to reconsider the issue of contemporaneity in fine-grained archaeological assemblages.

Less satisfying are the results from the 15 paired archaeological samples in table 1.3. These samples were selected to enhance the variability contained within the available radiocarbon record, and that variability carried through to the results of the data. These results have been tallied on table 1.4, and some impressions are in order. Of the 15 pairs, only three (H1, E1, and E2) have very large (more than 150 years) differences between their calibrated returns and their best-fit corrections. All of these pairs appeared to be flawed comparisons in that the materials being dated were not behaviorally contemporaneous. Of the remaining 12 pairs, half are within 55 years of their best-fit corrections when calibrated using the updated St. Catherines Island reservoir correction.

Unfortunately, there does not appear to be any consistent variation between the date of the samples and their relation to their best-fit corrections. The most ancient dates have an equivalently variable relation between their best-fit and corrected dates as the more recent dates.

Generally, the paired dates suggest that the remarkably high negative value of the St. Catherines Island reservoir correction is accurate, and if anything, the value is not negative enough. Ignoring the two pairs from the St. Catherines Island Shell Ring (E1 and E2), which appear to be flawed, only one of the returns (D2) suggests that the St. Catherines Island reservoir correction is overcorrecting our results.

CONCLUSIONS

This paper emphasized the necessity of explicitly exploring the nature of reservoir corrections along the Georgia Bight. Refining previous research by Thomas (2008: chap. 13), we took a number of new samples from known-age, prebomb shells of Crassostrea virginica and derived a new reservoir correction of –119 ± 16 14C years b.p., a value slightly less extreme than the previous estimate of –134 ± 26 14C years b.p. (as derived in Thomas, 2008: chap. 13). This revision both refines and expands the usefulness of this ΔR value. By employing sequential, high-precision dating across a single Mercenaria valve, we determined that the marine reservoir surrounding St. Catherines Island has been extraordinarily stable on a season-to-season basis. This portion of the Georgia Bight is totally lacking in the radical fluctuations within the annual cycle caused by varying supplies of old carbon resulting from upwelling, as noted elsewhere in the world. Finally, we ran numerous experiments attempting to determine whether the St. Catherines Island reservoir correction changes through time and we found no evidence of such change.

With respect to future research, we suspect that increasingly high-precision radiocarbon sampling and technology will allow more fine-grained approximations of ΔR values relevant to archaeological applications.

Figure 1.1. Location of 19th-century oyster factories on St. Catherines Island (after Thomas, 2008: fig. 13.4).

Figure 1.2. Map of St. Catherines Island showing modern oyster sample locations.

Figure 1.3. The steam-operated oyster boiler installed by Howard Coffin on Sapelo Island and used roughly 1920–1930.

Figure 1.4. This 1906 photograph shows the Shell Bluff Canning Company, located at Valona, on Shell Bluff Creek (Sullivan, 2000a).

Figure 1.5. Graph showing the minimal effects involved in recomputing the revised St. Catherines Island reservoir correction.

Figure 1.6. Probability profiles comparing the composite age for the Mercenaria sample from the McQueen Shell Ring (fig. 1.8 and table 1.4) with two closely correlated terrestrial 14C samples.

Figure 1.7. Paired samples from Late Archaic contexts on St. Catherines Island. The lightest gray symbols demonstrate the application of ΔR.

Figure 1.8. Simulated reservoir correction values for the pair A1 samples from the McQueen Shell Ring.

Figure 1.9. Paired samples from Late Prehistoric contexts on St. Catherines Island. The lightest gray symbols demonstrate the application of ΔR.

TABLE 1.2. Calibrated Results for 14C Transect Across Single Mercenaria Valve

Lab ID

Seasonality

14C Age

b.p.

Radiocarbon age calibrated (± 2σ)

UCIAMS-

80932

O1, Year 2,

Winter

3870 ±

20

2460–2290 cal b.c.

UCIAMS-

80933

T1-3, Year

3, Spring, Summer, or Fall

3900 ±

20

2470–2310 cal b.c.

UCIAMS-

80934

O1, Year 4,

Winter

3910 ±

20

2320–2310 cal b.c.

UCIAMS-

80935

T1-3, Year

6, Spring, Summer, or Fall

3915 ±

20

2470–2340 cal b.c.

UCIAMS-

80936

O1, Year 8,

Winter

3950 ±

20

2460–2210 cal b.c.

TABLE 1.3. Calibrated Results for Paired Charcoal-Marine 14C Age Determinations from St. Catherines Island

Lab ID

Species

14C Age b.p.

Radiocarbon age calibrated (± 2σ)

Pair A1: McQueen Shell Ring (9Li648), N243 E233, 4.3–4.2 m

Beta-251769

Mercenaria mercenaria

3830 ± 40

2130–1870 cal b.c.

Beta-251761

Charred material

3720 ± 40

2280–1980 cal b.c.

Pair A2: McQueen Shell Ring (9Li648), N243 E233, 4.5–4.4 m

Beta-251762

Mercenaria mercenaria

3820 ± 50

2140–1820 cal b.c.

Beta-251761

Charred material

3720 ± 40

2280–1980 cal b.c.

Pair B: McQueen Shell Ring (9Li648), Feature 38NE

Beta-258562

Mercenaria mercenaria

3810 ± 50

2120–1850 cal b.c.

Beta-258561

Charred material

3710 ± 50

2210–1950 cal b.c.

Pair C: McQueen Shell Ring (9Li648), N243 E233, 4.4–4.3 m

Beta-251768

Mercenaria mercenaria

3910 ± 40

2240–1960 cal b.c.

Beta-251767

Charred material

3680 ± 40

2200–1950 cal b.c.

Pair D1: McQueen Shell Ring (9Li648), N272 E200, 5.1–5.0 m

Beta-251765

Mercenaria mercenaria

3990 ± 50

2390–2040 cal b.c.

Beta-251766

Charred material

3800 ± 40

2440–2060 cal b.c.

Pair D2: McQueen Shell Ring (9Li648), N272 E200, 5.1–5.0 m/5.3–5.2 m

Beta-251765

Mercenaria mercenaria

3990 ± 50

2390–2040 cal b.c.

Beta-251764

Charred material

3710 ± 40

2210–1980 cal b.c.

Pair E1: St. Catherines Shell Ring (9Li231), N771 E819, 2.39–2.3 m

Beta-238336

Mercenaria mercenaria

4390 ± 60

2890–2570 cal b.c.

Beta-238337

Charred material

3860 ± 60

2460–2210 cal b.c.

Pair E2: St. Catherines Shell Ring (9Li231), N771 E819, 2.39-2.3 m

Beta-238336

Mercenaria mercenaria

4390 ± 60

2890–2570 cal b.c.

Beta-273291

Direct sherd date

3980 ± 40

2580–2350 cal b.c.

Pair F: Back Creek Village (9Li207), N488 E495, 49.79-.49 cm

Beta-242426

Mercenaria mercenaria

600 ± 40

cal a.d. 1500–1670

Beta-249873

Charred maize

450 ± 40

cal a.d. 1410–1620

Pair G: Back Creek Village (9Li207), Test Pit IV, 48.88-48.68 cm

Beta-242421

Mercenaria mercenaria

760 ± 40

cal a.d. 1380–1530

Beta-249874

Charred maize

410 ± 40

cal a.d. 1430–1630

Pair H1: Marys Mound (9Li20), Burial 2 (Thomas and Larsen, 1982)

UGA-1685

Crassostrea americana

1090 ± 60

cal a.d. 1060–1300

Beta-225470

Human bone

1030 ± 40

cal a.d. 900–1150

Pair H2: Marys Mound (9Li20), Burial 6 (Thomas and Larsen, 1982)

UGA-1685

Crassostrea americana

1090 ± 60

cal a.d. 1060–1300

Beta-225473

Human bone

910 ± 40

cal a.d. 1030–1210

Pair I1: Johns Mound (9Li18), Burial 10/Stage II (Thomas and Larsen, 1982)

UGA-64

Crassostrea americana

1190 ± 60

cal a.d. 980–1240

Beta-225475

Human bone

1070 ± 40

cal a.d. 890–1020

Pair I2: Johns Mound (9Li18), Central Pit/Stage II (Thomas and Larsen, 1982)

UGA-64

Crassostrea americana

1190 ± 60

cal a.d. 980–1240

UGA-61

Unidentified charcoal

900 ± 60

cal a.d. 1020–1250

Pair J: Seaside Mound I (9Li26), Central Tomb/Feature 15 (Thomas and Larsen, 1979: table 4)

UGA-1826

Crassostrea americana

1630 ± 60

cal a.d. 515–780

UGA-112

Unidentified charcoal

1430 ± 115

cal a.d. 390–870

TABLE 1.4. Comparison of 15 Pairs of Marine and Terrestrial 14C Ages from St. Catherines Island

(mean terrestrial/marine age disparity ≤ 200 14C years highlighted in gray)

Approximate age

cal a.d./b.c.

Simulated reservoir correction Range

14C years

Mean terrestrial/marine disparity

14C years

Pair designation

cal a.d. 1500

(-50 – -100)

350

Pair G (Back Creek Village)

cal a.d. 1425

(-150 – -200)

290

Pair F (Back Creek Village)

cal a.d. 1150

(-75 – -125)

100

Pair I2 (Johns Mound)

cal a.d. 1100

(-175 – -225)

120

Pair H2 (Marys Mound)

cal a.d. 1000

(~ 300)

60

Pair H1 (Marys Mound)

cal a.d. 950

(-225 – -275)

120

Pair I1 (Johns Mound)

cal a.d. 600

(-125 – -175)

200

Pair J (Seaside Mound I)

2050 cal b.c.

(-50 – -100)

230

Pair C (McQueen Shell Ring)

2100 cal b.c.

(-200 – -250)

100

Pair B (McQueen Shell Ring)

2100 cal b.c.

(-200 – -250)

100

Pair A2 (McQueen Shell Ring)

2100 cal b.c.

(-25 – -75)

280

Pair D2 (McQueen Shell Ring)

2100 cal b.c.

(-200 – -250)

110

Pair A1 (McQueen Shell Ring)

2250 cal b.c.

(-125 – -175)

190

Pair D1 (McQueen Shell Ring)

2300 cal b.c.

(~+100)

530

Pair E1 (St. Catherines Shell Ring)

2450 cal b.c.

(~+50)

410

Pair E2 (St. Catherines Shell Ring)

CHAPTER 2: AN ASSESSMENT OF COASTAL FAUNAL DATA FROM GEORGIA AND NORTHEAST FLORIDA

Alexandra L. Parsons and Rochelle A. Marrinan[4]

INTRODUCTION

Since the 1970s, significant progress has been made in the development of what broadly may be called “subsistence studies.” This generally has come to mean the analysis of plant and animal remains and the various kinds of studies derived from them. Although often underemphasized in textbooks or dismissively represented as “ecofacts,” these kinds of studies have broadened our understanding of prehistoric life in ways beyond the capabilities of what had previously been regarded as the mainstays of archaeological analysis: ceramics, lithics, skeletal remains, and settlement patterns. The oft-repeated rubric—that our goal is to understand (explain or explicate) prehistoric human behavior—is more truly realized by the addition of data produced by subsistence and environmental archaeological studies. The additions of archaeobotany, zooarchaeology, soils science, and climate data clearly have broadened our horizons and provided insights about human behavior regardless of our individual theoretical grounding or preferences.

In this chapter, we review available vertebrate faunal data from coastal Georgia and northeast coastal Florida to evaluate what we have learned about a variety of issues relevant to our inquiries as anthropological archaeologists. We consider historical motivations for faunal studies, their development, and their application to our study area. We also discuss disciplinary advances and how data generated since the 1970s inform us about sedentism, prehistoric environments, technology, and social behavior. Our review begins around 3000 b.c. and concludes around a.d. 1680. Our discussion includes samples from St. Catherines Island (St. Catherines Shell Ring, McQueen Shell Ring, and South End Mound I), Sapelo Island (Shell Ring III and Bourbon Field), Cathead Creek, St. Simons Island (Cannon’s Point Shell Ring and West Shell Ring), Kings Bay (Kings Bay and Devil’s Walkingstick), Fort George Island (Grand Shell Ring), Mill Cove Complex near Jacksonville (Kinzeys Knoll and the Bluff Midden and Grant Mound), Jacksonville Electric Authority sites (two sites), and Fountain of Youth site in St. Augustine (see appendix 2.1 for summaries of available faunal data). The majority of these samples were recovered from indigenous shell rings and middens. Our most numerous sources of data fall at the Late Archaic and Mississippi period extremes of the coastal chronology, although we have several intervening Woodland period sites as well. Our overview considers 16 sites from a 200 km stretch of the Atlantic coast.

All of the data we evaluate here were generated since the mid-1970s. We have selected a group of sites for which detailed faunal data have been published or are areas subject to our current research. Sites evaluated in this chapter meet the following criteria:

(1) indigenous sites from coastal Georgia and northeast Florida with access to a similar suite of estuarine resources,

(2) samples for which data on the number of identified specimens (NISP), weight, estimated biomass, and minimum number of individuals (MNI) calculations were available, and

(3) sites that create a representative chronological spread.

Several sites were excluded because they did not meet our criteria or because the resultant publications had missing or incomplete data. The samples reviewed here were published in peer-reviewed journals, books, dissertations, or are assemblages that we have analyzed.

METHODOLOGICAL ADVANCES

Spurred by the Danish kokkenmøddinger investigations, the study of riverine shell middens began in North America in the mid-19th century (Trigger, 1986: xi–xxiv). Attention first was paid to shell middens on the middle Atlantic coast (Vanuxem, 1843) and slightly later to those on the northeast coast of North America (Chadbourne, 1859). The shell heaps of the St. Johns River, Florida, were first explored in 1860 (Wyman, 1875). Shell middens and rings on the southeast Atlantic coast have been of interest since the late 19th century (e.g., McKinley, 1873). The shell heaps of the California coast, particularly in the vicinity of San Francisco Bay (Nelson, 1909), have received attention since Uhle’s (1907) work on the Emeryville Shellmound in 1902 and Nelson’s (1910) investigations at the Ellis Landing Shellmound in 1907. The latter investigations are well reported and illustrate recovered faunal remains. Excavations in California shell middens prompted concern for methodology, quantification, diet, and population estimates (Gifford, 1916; Cook, 1946).

The multidisciplinary projects of the 1950s and 1960s, specifically the Jarmo Archaeological Project (Braidwood, 1960), and the Tehuacán Valley Archaeological and Botanical Project (Flannery, 1967; MacNeish, 1967) brought specialists together, often in the field, and provided archaeologists with credible examples of what could be learned using zooarchaeological and archaeobotanical analysis. Although termed “multidisciplinary” or “interdisciplinary” instead of “conjunctive,” they nevertheless provided in spirit the new kinds of approaches that Taylor (1948) had envisioned and urged. These developments were not uniquely Americanist, however, as evidenced by early methodological compilations such as Heizer and Cook (1960) and Brothwell and Higgs (1969).

The most difficult aspect of this type of research was developing practitioners. The Koster Project, led by Stuart Struever in the early 1970s, provided an example of how an archaeological project could investigate a locality and provide training in a variety of subdisciplinary skills. Early scholars in this pursuit developed identification guides (Olsen, 1964, 1968, 1972; Casteel, 1976) and syntheses (Wing and Brown, 1979). In museums and academic institutions, individuals such as Paul Parmalee, Elizabeth S. Wing, and Kent V. Flannery assisted students in learning the rudiments of zooarchaeological analysis. There were fewer exemplars for archaeobotany, but Hugh Cutler, Richard I. Ford, Paul Manglesdorf, Margaret A. Towle, and Richard A. Yarnell were instrumental in introducing students to the study of plant remains and the publication of early archaeobotanical research.

These projects and individuals were stimuli for the broader field of archaeology and made the analyses of nontraditional materials both interesting and desirable. Prior to the 1960s, there were few guides to the identification and interpretation of animal remains (Cornwall, 1956). During the 1960s, Stanley J. Olsen (1964, 1968) published guidebooks to mammalian, avian, and reptilian remains. The greatest advance is evident beginning in the 1970s, however. This advance is marked by the founding of the International Council for Archaeozoology (ICAZ) in 1971, the appearance of overview publications on zooarchaeology (Chaplin, 1971; Grayson, 1984; Klein and Cruz-Uribe, 1984; Lyman, 1994, 2008; Reitz and Wing, 1999, 2008), the increasing availability of identification manuals (Schmid, 1972; von den Driesch, 1976; Gilbert, 1980, 1990; Gilbert, Martin, and Savage, 1981; Sobolik and Steele, 1996), and special publications on shell middens (Meehan, 1982; Stein, 1992). During this period there also were increasing numbers and sophistication of papers in professional journals such as American Antiquity, Journal of Archaeological Science, and Historical Archaeology (particularly the special publication by Reitz and Scarry, 1985).

Since the 1970s, the analysis of vertebrate and invertebrate fauna is more frequently a part of archaeological investigations. It is unfortunate that we have no grasp of the true number of field projects conducted in our coastal strand study area from the 1970s to the present with which to make comparisons. It is clear, however, that long-term research-based projects are the source of most of the samples used in this overview (N = 15). CRM projects have generated fewer of our samples
(N = 3: Cathead Creek, two time periods; Jacksonville Electric Authority site).

As a result of the call in the late 1960s for more rigorous field methods, screening became a more standard practice in fieldwork. The most common gauge is ¼ in., but finer screens are sometimes employed (particularly for features), and are almost always used for column samples. The choice of ¼ in. hardware cloth is often related more to concerns about available field time and analysis expense than to whether a representative sample is being obtained. In the coastal zone, the presence of invertebrate fauna increases screen time in the field or in the laboratory, depending on where the screened samples are processed. The use of 1⁄8 in. screen should be encouraged to recover a greater diversity of small-bodied species and to more accurately represent the faunal record. Faunal samples recovered using screens finer than 1⁄8 in. may require specialists with substantial experience in microscopic identification. Given the widespread use of ¼ in. screen, many comparable samples have been generated, but concern remains regarding what is lost (Newsom and Wing, 2004: 41; Quitmyer, 2004).

Comparative collections are critical to the process of identification, and are now available in research institutions, agencies, and cultural resource management firms. The Florida Museum of Natural History’s Environmental Archaeology Laboratory has been a leader in this effort, as have the Zooarchaeology Laboratory of the Georgia Museum of Natural History and the Zooarchaeological Research Facilities at the University of Tennessee. Several academic institutions offer both courses and research opportunities that help to prepare new practitioners.

Many analysis measures are now standard practice in zooarchaeological reporting and discussion. Measures such as the number of identified specimens (NISP), specimen weight, estimated biomass, number of thermally altered, worked, or butchered bones, and the minimum number of individuals calculation (MNI) are regularly provided (Lyman, 2008; Reitz and Wing, 1999, 2008). Issues such as preservation bias, taphonomic processes, ethnoarchaeology, natural versus cultural faunal assemblages, feasting, and ritual use of animals have been the subjects of professional papers since the late 1960s. The availability of faunal data has contributed to theoretical arguments such as the role of humans in plant and animal extinction, optimal foraging strategies, feasting and ritual behavior, and resource overexploitation and decline in coastal ecosystems.

How to relate recovered vertebrate faunal remains to dietary contribution has been a continuing discussion. Early methods, such as that proposed by White (1953), used an averaged standard weight and the MNI to estimate the meat-weight contribution of mammalian fauna. The introduction of estimated biomass using allometric scaling, by Reitz and colleagues (Reitz et al., 1987), has provided a means of representing the dietary contributions of mammals, fish, reptiles, and birds. Although this method has its critics (see Jackson, 1989), it is a valuable means of comparison within and among samples and is easy to use because it is based on the weight of vertebrate bone recovered from archaeological contexts.

Since the mid 1970s, zooarchaeologists have produced datasets that anchor comparisons of findings from a number of coastal Georgia and Florida sites. Not all reports of faunal datasets are adequate, however. Missing data on standard measurements such as weights, missing data on screen size, and lack of contextual information negatively impact the usefulness of faunal reports. A standardized approach to analysis and reporting that includes standard measurements such as weights, counts, MNI, and biomass permits faunal assemblages to be compared and overall patterns to be identified across sites.

THE SITES

St. Catherines Island Shell Ring (9Li231) is one of two Late Archaic shell rings on St. Catherines Island. The site is located near a salt marsh on the leeward side of the island and was first recorded in 1979 during systematic sampling of the island (Thomas, 2008: chap. 20, 555–557). During this transect survey, three test pits were excavated in the ring matrix, a volume totaling approximately 2.6 m3. Remains were screened over ¼ in. hardware cloth. Reitz (2008) analyzed vertebrate faunal remains from this excavation. Beginning in 2006, more extensive excavations were undertaken at the site. In the ring interior, excavation revealed a number of pit features with steep sides and flat bottoms, approximately 1 m in diameter (Sanger and Thomas, 2010). These features were relatively devoid of material culture or food remains and slightly predate construction of the shell ring. Based on remote sensing, Sanger and Thomas (2010: 59) estimate that 500 of these features are present within the ring interior. Colaninno (2010) analyzed samples from six 1 × 1 m excavation units located in the north, east, and west arcs of the ring, as well as two interior features (totaling approximately 11.8 m3). The materials analyzed by Colaninno (2010) were water-screened over 1⁄8 in. mesh.

McQueen Shell Ring (9Li1648) is the second Late Archaic shell ring on St. Catherines Island. The McQueen Shell Ring was discovered in 2007, and has been the subject of extensive excavations by the American Museum of Natural History. The McQueen ring is located on the seaward side of the island adjacent to a salt marsh protected by a dune ridge. The ring is approximately 70 m in diameter and is 30–70 cm in height (Colaninno, 2010). Colaninno (2010) examined vertebrate faunal remains from two 1 × 1 m excavations in areas of high elevation in the southern and northwestern arc of the ring that amounted to approximately 1.2 m3. These materials were water-screened over 1⁄8 in. mesh.

South End Mound I (9Li3) is a mortuary site that was first excavated by Moore (1998 [1897]) in 1896. He exposed 50 burials: one cremation, four secondary urn burials, and 45 primary burials (Larsen, 2002). Based on the ceramics, the site dates to the Irene (Mississippi) Period. Moore excavated all but a small portion of the mound. During his excavation, he encountered a large concentration of oyster and clam shells within the burial mound, which is likely responsible for the excellent preservation of skeletal remains. Upon completion of the excavation, Moore backfilled the mound, leaving most of the skeletal remains roughly in their original location.

Larsen and Thomas undertook excavations at the South End Mound in 1979, 1981, and 1991–1993. The latter excavations included 13 2 × 2 m units and a single 1 × 2 m unit approximately 1 m deep, the remains of which were screened through 1⁄8 in. hardware cloth (Larsen, 2002). Reitz et al. (2002) reported on the faunal remains obtained from these excavations. During removal of Moore’s backfill, abundant oyster was encountered, verifying the shell deposit described by Moore (Larsen, 2002).

Sapelo Shell Ring Complex (9Mc23) is a shell ring complex on Sapelo Island that contains three shell rings: rings I, II, and III, and a number of amorphous shell middens. William McKinley (1873) first described the shell ring complex in 1872. Moore (1998 [1897]: 73) visited the site and referred to Ring I as “an aboriginal fortification or ceremonial enclosure.” Moore’s excavations revealed no burials but he recovered a temporal bone from a human skull (Moore, 1998 [1897]: 73). Ring III is the smallest of these rings, with a diameter of approximately 50 m (Thompson et al., 2004). Thompson (2006) conducted the most recent excavations at the Sapelo Ring Complex. Colaninno (2010) analyzed vertebrate faunal remains from two contexts of Ring III: a 25 × 25 cm column sample in unit 9 (in the southwest portion of the ring) and unit 4 (in the northwest arc of the ring) where dense shell deposits remained. The column sample was screened over 1⁄8 in. mesh and the unit 4 material was screened over ¼ in. mesh.

Bourbon Field is an approximately 14 hectare (ha) area adjacent to a marsh at the north end of the eastern side of Sapelo Island (Crook, 1984: 187). It is a multicomponent site consisting of 119 shell middens and a small earthen mound. Moore (1998 [1897]: 55–67) excavated two burial mounds at Bourbon Field: a large truncated mound (9Mc20) that Moore assigned to the Irene-San Marcos period based on the ceramic assemblage, and a second “low” mound (9Mc21) that Moore hypothesized dated to the Woodland period.

Crook (1984) sampled 10 shell middens and several off-midden areas for a total of 54 2 × 2 m units. The middens include occupations from a number of periods: St. Simons (Late Archaic), Deptford, Wilmington (Woodland period), Savannah, and Irene-San Marcos (Mississippi period), with the latter two periods being the best represented. The majority of the excavated matrix was screened through ¼ in. hardware cloth. Twenty-liter samples of matrix were screened through nested sieves with a minimum size of 1⁄16 in., but the ¼ in. fauna was removed and added to the ¼ in. general level (block excavation) samples (Crook, 1984; Reitz, 1982). Reitz (1982) stated that approximately 94% of the sample was screened through ¼ in. mesh, while the remaining 6% was screened through fine mesh.

Several column samples were analyzed, but fine-screened materials from the plowzone (~30 cm) were not included in the faunal analysis (Crook, 1984). The Savannah- and Irene-period faunal assemblages are reported together, so we are unable to differentiate subsistence between the two periods. Crook (1984) designated the Savannah time period as a.d. 1000–1540, and the Irene-San Marcos period as 1540–1680 based on Milanich’s (1977) chronology. In his interpretation, Crook (1984) described the Irene-San Marcos period occupations in terms of both sacred and domestic spaces. Based on midden distribution, Crook (1984: 263) argued that the first signs of formally organized space are evident in the Savannah period, with a reorganization of domestic space in the Irene-San Marcos period and further, that these new spatial arrangements may have been related to the increasing importance of maize agriculture. Drawing from Larsen’s (1982) work on St. Catherines Island, Crook (1984: 263) stated that osteological evidence indicates that maize was becoming an important dietary item in the Savannah period, although maize remains were rarely encountered during excavations.

Cathead Creek (9Mc360) is a shell midden site located on a 7 m tall bluff at the convergence of Cathead Creek and Darien River (Reitz and Quitmyer, 1988). The Darien River is somewhat brackish and is responsive to tidal changes (Reitz and Quitmyer, 1988). The midden is approximately 1.6 m deep, with Mississippian remains in the upper 90 cm of the midden. Swift Creek refuse was recovered from the lower 70 cm. Materials were excavated by Lucy B. Wayne (Air and Water Research, Inc.) and Reitz and Quitmyer (1988) analyzed 10 liter samples from five levels within a single 1 × 1 m unit. Samples were screened through geological sieves with a minimum size of 1⁄5 in. (0.5 mm). Faunal remains are reported as two assemblages based on chronology, one Swift Creek assemblage and one Savannah assemblage (Woodland and Mississippi periods, respectively).

Cannon’s Point Shell Ring (9Gn57) is a Late Archaic shell ring lying in the marsh on the east side of the north end of Cannon’s Point on St. Simon’s Island, Georgia. It was identified in the fall of 1972, and Marrinan (1975, 2010) conducted excavations there in subsequent years. The ring is isolated from the mainland, but when it was deposited, it was probably on the mainland edge. It is possible that eustatic sea level rise or changing tidal creek/marsh/mainland relations accounts for its current isolation. The ring is approximately 68 m (east-west) by 44 m (north-south) and has been breached on its northeast side. Marsh grasses grow in its center, water enters at high tide, and approximately 1 m of sediment has been deposited in the area.

The faunal sample is drawn from excavation unit 18N, 0E, a 3 × 3 m test placed near the highest elevation of the ring on its northwest arc. Excavation fill was dominated by oysters, most of which appeared to be single, not clumped specimens. Also present were quahog clams and a variety of less numerous invertebrate species, both estuarine and terrestrial. The depth of deposit was 1.65 m. The vertebrate faunal sample was recovered from an approximate volume of 13 m³ (taking baulks into account) and was water-screened through 1⁄8 in. hardware cloth.

West Ring (9Gn76) is the second of two shell rings on St. Simons Island. It is located on high ground approximately 100 m southwest of the Cannon’s Point Shell Ring (Marrinan, 1975). The ring is 42 m in diameter and its southeast side is currently eroding into the adjacent salt marsh. Faunal remains were recovered from a volume of approximately 2.8 m³ and were water-screened through 1⁄8 in. hardware cloth. The data reported here represent a single 2 × 2 m unit (5S, 30E) placed in the east arc of the ring.

Kings Bay (9Cm171) is located on the mainland in Kings Bay Naval Station, and is a 91.5 ha site composed of several small, discrete shell middens near the marshes of the Cumberland Sound (Reitz and Quitmyer, 1988). Material culture spans the Late Archaic through historic periods. Analyzed faunal materials were associated primarily with the Woodland Period. The majority of the samples were located in three arbitrarily defined sections of the site: Artesian Well, Poisonberry, and Bluff areas. These areas date from the Swift Creek Period and contained the least disturbed cultural remains (Saunders, 1986: 22). The excavation was conducted by the University of Florida under the direction of William H. Adams. Reitz and Quitmyer (1988) analyzed samples from three Swift Creek features that were interpreted as trash pits. These samples were water-screened over a minimum of 1⁄16 in. mesh.

Devil’s Walkingstick (9Cm177) is a series of small discrete middens located in the Kings Bay Naval Station, approximately 2 km away from the Kings Bay site. Quitmyer and Reitz (2006) analyzed the Savannah period remains from three areas: 11 50 × 50 × 10 cm column samples and two features from the North Bunker Area, a single feature from the South Bunker Area, and a single feature from the Marsh Area. These materials were sieved over a minimum of 1⁄16 in. screen.

Grand Shell Ring (8Du1) is an early Mississippian shell ring and earthen mound site that has been known since the late 19th century. Since Moore could not obtain permission to excavate there, professional excavation has only been undertaken recently. As would be expected, looting has occurred through the years, mostly in the sand burial mound that overlies the shell ring midden on its west arc. In 2006, Ashley, Rolland, and Marrinan (2007) excavated a trench of seven 1 × 2 m units through the southern arc of the ring. The sample used here was recovered from a volume of approximately 13 m3 and was screened over ¼ in. hardware cloth. Faunal analysis of this material was reported in Ashley, Rolland, and Marrinan’s 2007 report, but we have recently completed analysis on unanalyzed samples. A composite spreadsheet including the newly analyzed material is presented in appendix 2.2.

The Mill Cove Complex is an Early Mississippi period group of two mounds, earthworks, and midden deposits located on the east bank of the St. Johns River near present-day Jacksonville, Florida (Ashley, 2003, 2005). Grant Mound (8Du14) and Shields Mound (8Du12) lie approximately 750 m apart: Grant to the west and Shields to the east. South of the Shields Mound, there are earthen ridges, which have not been investigated. The Grant Mound has been threatened by erosion for several centuries and it is likely that more than half of it has washed into the river (Moore, 1999 [1894]; Thunen, 2005). Between and around the mounds, there are small shell midden deposits. C.B. Moore (1999 [1894]) first reported these sites and later investigated both Grant and Shields mounds. Ashley (2003, 2005) and Thunen (2005) have conducted excavations in both mounds and in a number of the midden deposits in the area. Specific sites and areas in the Mill Cove Complex are discussed below.

Shields Mound (8Du12) is a large, oblong platform mound lying on a relict sand dune overlooking the St. Johns River (Moore, 1895). It is primarily composed of sand, but there are lenses of shell midden. C.B. Moore excavated this site in 1894 and 1895 and characterized it as unusual for the St. Johns area. He recovered both extended and bundled burials and noted that they were usually associated with ground hematite pigment. Grave goods included items of copper, galena, exotic stone (celts and axes), earthenware and soapstone pipes, bone pins, and chert projectile points. The mound is surrounded by a number of midden deposits and our samples derive from two of these: Kinzeys Knoll and the Bluff Midden.

Kinzeys Knoll (8Du5606) is a dense dome-shaped shell midden approximately 30 m (north-south) by 25 m (east-west). It is located approximately 30 m northwest of Shields Mound, and although the midden is adjacent, it does not appear to be contiguous with the mound. Our samples come from four contiguous 1 × 1 m units placed in the southeast sector of the midden. The deposit reached a depth of 80 cm, and excavated material totaling 3.2 m³ was screened over ¼ in. mesh. Rolland (2005: 231) analyzed the ceramics recovered from this area, and concluded that they were unlike all other areas sampled in the vicinity of Shields Mound. She considered them to represent a ceremonial assemblage (Rolland, 2005: 226). These collections contained more large vessels and open serving vessels, the highest frequency of decorated sherds, an estimated vessel count of 350 (from a total of 2535 sherds), and an unusual percentage of hematite-slipped or hematite-impregnated ceramics (84 sherds, or 3%) in contrast to other excavation areas (Rolland, 2005). The vertebrate and invertebrate fauna and ceramics were recovered with a number of broken items: bone pins, copper, greenstone, shark and dolphin teeth that were worn and battered, and chunks of hematite. It appears that each of these materials was discarded at the end of its functional use-life.

The Bluff Midden (8Du5605) is approximately 80 m in length and 20 m at its widest. Its center lies along the bluff edge approximately 130 m from the northwest edge of Shields Mound. Our samples come from two contiguous 1 × 2 m units (units 7 and 8) located near the center of the midden. At this location, the midden is approximately 60–65 cm deep. The vertebrate sample was recovered from a midden volume of 2.5 m³, which was screened over ¼ in. hardware cloth. Rolland’s (2005: 221–224) ceramic analysis indicated that the use-life of Bluff Midden vessels had been longer in duration and suggested that their use may have been more domestic than ceremonial.

Grant Mound (8Du14) was described by Moore (1999 [1894]) as a truncated conical mound rising over 26 ft above the bluff on which it stood. Moore (1894: 200) also noted that one-third of its mass had been washed into the river exposing “a rich harvest of aboriginal relics.” Thunen (2005: 259) recovered our samples during excavations in 1989. The analysis of faunal remains from two 2 × 2 m units (screened over ¼ in. mesh) is currently unpublished, so we have included the composite spreadsheet in appendix 2.2. Test Unit 2 was located along the flank of the mound on its west margin. Its upper eight levels were mound fill and the faunal collection was very sparse. Fauna from its lower 11 levels were recovered from dense shell midden. Unit 4, located off the mound proper, was placed in shell midden. For the purposes of this overview, we have combined the lower midden levels of Test Unit 2 with Test Unit 4. In estimating the midden fill from which these faunal samples were recovered, Test Unit 2 represents approximately 4.4 m³ and in Test Unit 4, the midden depth is reported as 52 cm (2.1 m³) for a total of 6.5 m³.

Jacksonville Electric Authority Sites (8Du634 and 8Du669) are mainland sites with a number of small shell middens near a salt marsh in the St. Johns River drainage (Reitz, Quitmyer, and Marrinan, 2009). The University of West Florida Office of Cultural and Archaeological Research conducted excavations in order to mitigate proposed construction on the property (Lee et al., 1984). Twelve shell middens were encountered during excavation, revealing occupation primarily during the late prehistoric period (a.d. 1200–1500) (Lee et al., 1984). Lee and colleagues interpreted the site as a seasonal, low-density occupation and hypothesized that the sites were occupied by mobile inland groups who returned to the area intermittently, perhaps to supplement their maize diet (Lee et al., 1984: 4).

Elizabeth Wing and Irvy Quitmyer analyzed zooarchaeological materials from the Jacksonville Electric Authority sites. Samples were taken from flotation material from features, as they were better preserved in the shell middens than in the general level acidic soil (Lee et al., 1984). The screen sizes include a minimum of 1⁄35 in. Seven column samples were analyzed from 8Du634, and eight column samples were analyzed for 8Du669. The allometric scaling formulas outlined by Reitz and colleagues (Reitz et al., 1987) were unavailable for use in the Lee et al. (1984) report. As such, different formulas were used to estimate biomass. In order to make the estimated biomass more comparable to other sites in our review, we have used the quantifications of a subsample reported in Reitz et al., 2010 (they utilized the more recent allometric scaling formulas). Reitz et al. (2010) report that this sample was screened over 1⁄16 in. mesh.

Fountain of Youth (8SJ31) is a multicomponent site adjacent to a salt marsh, tidal creeks, and Hospital Creek. Hospital Creek flows into the Matanzas River, which forms a large embayment with an outlet to the sea a short distance away. Excavations recovered fauna from the Late Archaic Period, St. Johns II (Mississippi Period), a brief Spanish occupation in 1565, and the later mission period (Reitz, 1991). Survey of the site identified two St. Johns II shell middens, along with a St. Johns II village located between the middens. Ed Chaney conducted fieldwork under the direction of Kathleen Deagan in 1985 and 1987 (Chaney, 1987). Chaney (1987: 11) based his interpretation of the village on the presence of numerous circular postmolds, associated with hearths and trash pits. Materials included in our discussion are from the Late Archaic and St. Johns II periods and were screened over 1⁄16 in. hardware cloth; these remains were analyzed and reported by Reitz (1991).

DISCUSSION OF THE SAMPLES

A variety of decisions are made that affect zooarchaeological analysis. The first decisions include protocols for sampling (how much will be removed) and screen size (what screen size will be used for which kinds of samples). These kinds of decisions also continue when the samples reach the laboratory. Given the sheer size of some field collections and the cost of analysis, subsamples may be required. The samples discussed above were recovered using a variety of screen sizes, primarily ¼ in. and 1⁄8 in. mesh. The sizes of excavations and analyzed samples also varied greatly, ranging from column samples to large block excavations. Although excavation strategies differed, analysts quantified the above samples using standard zooarchaeological methods and measurements. In the discussion below, we attempt to mitigate different recovery strategies to compare the faunal assemblages and to make generalizations about subsistence in the Georgia Bight.

Evident in these samples is the overwhelming dependence on salt marsh and estuarine resources. A pattern of broad-spectrum harvesting—through collection of shellfish and fishing—is clearly present from the Late Archaic through the Mississippi Period. The data we have reviewed are insufficient to address specific changes in subsistence through time. The Kings Bay and Devil’s Walkingstick assemblages (Woodland and Mississippi periods) suggest considerable continuity. However, the two multicomponent sites show differences in animal use that are difficult to interpret. The Cathead Creek assemblages (Woodland and Mississippi) are similar, but demonstrate slightly different proportions of mammals and fish. The Fountain of Youth assemblages (Late Archaic and Mississippi) are quite different, but the Late Archaic sample is rather small and perhaps not a complete representation of the diet. More faunal assemblages must be analyzed in order to tease apart local variability from large-scale changes in subsistence through time.

Overall, the data indicate that a similar subsistence strategy persisted for several thousand years in the Georgia Bight. In terms of how many species were exploited, the diet was broad at both shell ring deposits (e.g., Grand Shell Ring) and midden deposits (e.g., Grant Mound Midden). Nevertheless, reliance on a lesser number of species is evident. From the marsh-estuary environments, marine catfishes, mullets, and drums tend to be the primary resources in terms of estimated biomass. Species such as herrings, jacks, flounders, and porgies (sheepshead) provide a second tier of dependence.

Less common are assemblages with high concentrations of terrestrial fauna. Although deer and a variety of other mammals are present, in general they are lower contributors to estimated biomass. In our samples, there are several exceptions—primarily from St. Catherines Island. At the sites we review, mammal biomass comprises anywhere from 1.8% (Fountain of Youth–Mississippi Period) to 95% (South End Mound I) of the vertebrate biomass (fig. 2.1). The amount of mammalian biomass does not seem to correspond to any particular time period, nor does it increase or decrease through time in any predictable way. Sites located on St. Catherines Island (particularly the South End Mound I and St. Catherines Shell Ring) generally contain higher percentages of mammal remains when compared to other sites in the Georgia Bight. Although the St. Catherines Shell Ring materials analyzed by Reitz were recovered using ¼ in. screen, the materials analyzed by Colaninno (2010) were recovered using 1⁄8 in. screen. The material analyzed by Colaninno (2010) showed a slight decrease in the percentage of mammalian biomass but overall mammalian biomass remained remarkably high. The South End Mound material was also recovered using 1⁄8 in. screen. This indicates that the use of ¼ in. screen does not explain the unusually high percentage of mammalian remains on St. Catherines Island. As at other sites, deer contributes most of the estimated mammalian biomass percentage. On St. Catherines Island, it appears that deer were an exceptionally important part of the vertebrate diet. It is currently unclear why deer remains are so ubiquitous on St. Catherines Island. Reitz et al. (2010: 59, 75) discussed two possibilities for the high number of deer remains at Sea Island sites: circumscription of deer lowered the energy costs of acquiring such animals or the ecological diversity of the larger Sea Islands may have supported more deer than mainland locations.

The South End Mound I assemblage was recovered from a disturbed mortuary context containing secondary midden fill. Several explanations are possible for the large amount of mammal remains: (1) they are a result of the ritual nature of the burial mound (Reitz, Larsen, and Schoeninger, 2002), (2) they are food offerings associated with mortuary rites (Reitz et al., 2010: 69–70), or (3) the transport of midden material may have resulted in the loss or exclusion of smaller fish remains, and favored the inclusion of larger mammalian remains in the deposit. Moore (1998 [1897]: 161) stated, “Local layers of oyster shells were present, and the central portion of the mound was made up of a deposit of oyster shells about 2 feet thick—not midden refuse but loose as though brought there at one time and deposited.” It is clear that the faunal materials recovered from South End Mound I do not fully represent the diet of those interred in the mound because isotopic analysis of their remains indicated a heavy reliance on maize (Larsen, 2002), as well as a strong marine orientation (Reitz et al., 2010).

Bourbon Field also had an exceptionally high percentage of mammalian biomass. The faunal assemblage reflects both Savannah and Irene–San Marcos Period deposits; as such, we are currently unable to distinguish chronological differences in subsistence. It is possible that if these groups were growing maize (see Crook, 1984: 263), they may have engaged in garden hunting, resulting in a higher proportion of mammal (especially deer) remains (see Reitz et al., 2010: 53).

Elsewhere, Marrinan and Parsons (2008) proposed that high percentages of mammal remains in coastal sites might be indicative of ritual or ceremonial contexts. We argued that in a coastal setting, people might have sought out mammals for feasts or rituals as a departure from daily subsistence focused on fish and shellfish. Following Dietler and Hayden’s (2001: 3) definition of “feast,” we characterize feasts as events focused on the communal consumption of food and/or drink that is different or separate from everyday meals. Our proposed link between mammal remains and ritual contexts was based on the faunal assemblages from four early Mississippi Period sites in northeast Florida: Kinzeys Knoll and Bluff Midden (adjacent to Shields Mound), Grant Mound, and the Grand Shell Ring. Shields Mound, as a monumental construction and place of burial, is a locale in which we would expect ritual and ceremonial activities. Further evidence for a ritual or ceremonial nature of the deposit can been seen in the presence of primarily large ceramic vessels, a large quantity of ceramics and bone pins, presence of exotic goods (e.g., greenstone, copper, and ochre), and unusual faunal remains (e.g., bear, gar dentaries, utilized porpoise teeth) (Marrinan and Parsons, 2008). When compared to other sites in the Georgia Bight, the Shields assemblages do not appear to be particularly high in mammalian biomass (especially compared to the St. Catherines Island sites). However, when they are compared to other Mississippi Period sites in northeast Florida, the mammalian biomass is clearly unusual. It is possible that in northeast Florida during the Mississippi Period, feasts and ritual events involving food differed from other settings because of the lack of maize agriculture. Currently, there is no evidence for maize agriculture in northeast Florida during the St. Johns II Period (a.d. 900–1250) (Ashley, 2005). The earliest evidence of maize consumption in northeast Florida does not appear until the 16th century in contexts associated with Spanish missions (Ashley, 2005: 279).

Avian fauna are present but not numerous in the assemblages (fig. 2.2). Their remains are more fragile and may have been broken in the heavy shell matrix beyond our means of identifying them. Relatively few avian remains were recovered from the examined sites; estimated avian biomass ranged from 0% (Fountain of Youth—Late Archaic, Sapelo Ring III, Cathead Creek—Woodland, and Jacksonville Electric) to 5.3% of the total biomass (Kinzeys Knoll), with most samples (N = 10) containing less than 1%. Avian biomass was highest in Kinzeys Knoll, followed by Grand, Grant, and Bluff. This may represent a local focus on birds, or it may be the result of taphonomic processes.

The biomass estimates for reptiles are rather diverse, ranging from 1% (McQueen Shell Ring) to 10.7% (Jacksonville Electric) of the vertebrate biomass (fig. 2.3). Reptiles, predominantly turtles, are generally well represented in estimates of contributed biomass. Although reptiles are usually third in importance (after fish and mammals), in some cases their contributions are second only to fish (ray-finned fishes and cartilaginous fishes). Turtles from all habitats were taken. Turtles with highly sculptured carapaces (e.g., chicken turtle, diamondback terrapin, and sliders) are often the prime targets, suggesting that an aesthetic sense may motivate their capture (Marrinan, 1975).

Based on the sites we have reviewed, fishes (ray-finned, sharks, and rays) usually contribute the highest estimated vertebrate biomass (fig. 2.4). Fish biomass contributed 50% or more to the overall sample in all but four collections: South End Mound I, St. Catherines Ring, Bourbon Field, and the Bluff Midden. Fish and mammalian biomass are essentially inversely related: when fish biomass declines, mammalian biomass increases. Fish and mammals (especially deer) were undoubtedly the most important vertebrate contributors to diet in the coastal strand.

It is likely that the biomass estimates discussed above would be small in comparison to the invertebrate biomass. Shellfish, always the most numerous in every measure, have not been treated with the same level of quantification as the vertebrate constituents of shell rings and middens. It is a massively time-consuming prospect to quantify invertebrate midden constituents. In the few studies in which this has been attempted, the estimated biomass of shellfish dwarfs all other midden constituents (e.g., Kinzeys Knoll—Marrinan, 2005: table 4). Crabs are recovered in both shell ring and midden sites. When found in large numbers in features, they and the other materials recovered with them may represent a single meal.

Faunal Density

One problem faced when comparing faunal assemblages from different sites is that different gauge screens may have been utilized to recover remains. Quitmyer (2004) demonstrated that NISP and often MNI dramatically increase with use of small-gauge screens, driven primarily by the increase of small fish remains. The samples we have examined were sieved through screens ranging from 1⁄35 in. to ¼ in. Another problem with comparing faunal assemblages is that the amount of excavated fill and analyzed fauna ranges from very small to very large samples. The amount of matrix that is excavated and screened highly influences the NISP, weights, and biomass estimates. Several of the samples we review were removed solely from column samples and features, but others were obtained from large block excavations. To overcome these difficulties in making comparisons, we have calculated the vertebrate faunal density for nine sites. Following Sidrys’s (1977) use of lithic density to measure relative quantities of obsidian in Maya sites, we calculated faunal density by dividing the relevant variable by the number of cubic meters excavated and analyzed. Table 2.1 provides faunal density data for six sites. The NISP and MNI rankings appear to be similar, but biomass is not always similarly correlated. Because NISP and MNI are highly dependent on screen size, we chose to evaluate faunal density using estimated biomass values. Using estimated biomass allowed us to mitigate some of the effects of screen size and calculate the approximate amount of food that was generated by the remains in each cubic meter of midden matrix.

For our comparisons, we included samples that were obtained from excavations larger than one cubic meter. Because shell midden density is often variable, we selected samples of at least 1 m3 to avoid extrapolating density for unexcavated or unanalyzed portions of the midden deposit. Volumetric data regarding the provenience of the analyzed faunal sample were lacking from most publications. We have calculated the faunal density for nine sites for which data were available, including five shell rings—St. Catherines (combined data from Reitz, 2008, and Colaninno, 2010), McQueen, Cannon’s Point, West, and Grand; three middens—Grant, Kinzeys, and Bluff; and the mound fill of South End Mound I (table 2.2).

Faunal density based on biomass estimates varied considerably in the samples (fig. 2.5). We define four categories of faunal density: very low (0–999 g), low (1000–4999 g), high (5000–14,999 g), and very high (15,000 g and above). We did not identify any patterns regarding faunal density and biomass contributions of particular classes of fauna. Faunal density was lowest at South End Mound I (our very low category, with only 297.8 g of biomass per m³). The very low faunal density is unsurprising since the midden was only a small portion of the burial mound fill. Faunal densities at the shell rings varied, although most were in the low category: Cannon’s Point, West, and St. Catherines fell into the low category, but McQueen and Grand were in the high category. Grant and Bluff middens were also in the high category. Kinzeys Knoll was quite literally off the charts, with an estimated 25,566.1 g of biomass/m3. The Kinzeys Knoll deposit has been proposed as an assemblage that represents feasting (Marrinan, 2005). The extremely dense faunal deposit may be the result of ritual feasts, but comparisons with other feasting assemblages are needed to evaluate whether faunal density can be linked to ritual behavior and feasting.

Calculations of faunal density may provide some insight into the nature of the deposit. Russo (2004) has commented on the use of the term “clean shell” to indicate that large quantities of loose oyster shells comprise shell ring fill. He suggests that this observation may indicate intentional mounding of shell. In this case, sites with low density include all of the Late Archaic shell rings with the exception of McQueen. We are unsure of the reasons why the McQueen sample differs, but its excavated and analyzed volume is considerably lower than the other samples. If most Late Archaic shell rings evidence a lower density of vertebrate fauna than later period sites, there may be a different depositional pattern.

ARCHAEOLOGY OF COASTAL GEORGIA AND NORTHEAST FLORIDA

Seasonality Studies and Sedentism

Faunal analysis has made strides in the study of food consumption, which also has provided an indication of season of site occupation. Seasonality studies offer the opportunity to understand patterns of mobility or settled life in the coastal zone. These studies provide direct evidence of human presence at a site during specific seasons of the year. Archaeologists are interested in knowing when a society becomes sedentary for a multitude of reasons. A sedentary lifestyle requires more than a simple cessation of movement on the landscape; social behaviors must change to cope with sustaining continued occupation in a single area. Solutions must be found for complex problems, such as procuring food from a limited area throughout the year, developing seasonal schedules of procurement to prevent food shortages, and tolerating extended periods of communal living. To ensure that resources are not depleted and food shortages do not ensue, both individual and group foraging must be reorganized (Kelly, 1998) and this may mean broadening the resource base (Reitz, and Wing, 1999: 253).

Until the 1970s, intensive faunal analyses for coastal sites in the Georgia Bight were lacking. Previously, elaborate models of migration between coastal and inland areas were used to explain the presumed lack of appeal for living on the coast during particular seasons of the year. Traditional markers of sedentism, such as storage pits, ceramics, deep midden deposits, large site size, formal cemeteries, large populations, cultivated or domesticated plants, and a dependable subsistence economy, have been described by Binford (1980), Price and Brown (1985), Rafferty (1985), Kelly (1998), Rocek (1998), and Russo (1998). In the southeast U.S., these characteristics were often considered inadequate evidence for sedentism at early coastal sites. Although many archaeologists considered coastal sites to be short-term seasonal occupations, some thought that these sites were occupied by relatively sedentary societies that had successfully adapted to the coastal strand in general and estuarine and marsh ecosystems in particular.

Analysis of the faunal samples from the shell rings on St. Simons Island (Marrinan, 1975) in the mid-1970s suggested year-round use of the sites. These data, a combination of faunal and floral indicators, were contrary to then-current conceptions of Archaic people as mobile hunters and gatherers. Since that study, the evidence supporting permanent residence has increased. The addition of quahog clam seasonality data (Quitmyer, Hale, and Jones, 1985a, 1985b) to coastal faunal studies represented a breakthrough that generated yet more evidence of extended residential occupation from the Late Archaic to Mississippian times. The publication of the modern comparative collection from Kings Bay, Georgia (Quitmyer, Hale, and Jones, 1985a, 1985b; Quitmyer, Jones, and Arnold, 1997) facilitated numerous quahog clam studies in the surrounding area. The ability to assess the season of death for quahogs was an important advance, given their frequency in coastal middens. While oysters are typically more numerous than clams in shell middens, determining their season of death has proven to be less straightforward. Research to refine oyster seasonality studies is ongoing; however, archaeologists have used isotopic analysis (e.g., Thompson and Andrus, 2011) as well as size-class studies of Boonea impressa (e.g., Russo, 1991) to evaluate oyster seasonality. Recently, Colaninno (2010) has undertaken isotopic assessment of fish otoliths to evaluate seasons of capture at three shell rings on the Georgia Sea Islands.

Over the last 40 years, seasonality data have been amassed from numerous sites in the Georgia Bight. These datasets suggest that from the Late Archaic through the Mississippi Period, coastal groups were relatively sedentary (Marrinan, 1975; Quitmyer, Hale, and Jones, 1985b, Quitmyer, Jones, and Arnold, 1997; Russo, Cordell, and Ruhl, 1993; Ashley, Rolland, and Marrinan, 2007; Parsons, 2008, 2012; Quitmyer and Jones, 2012). In many sites, it appears that some part of the population remained in a single location throughout much of the year. This provides a significantly different picture than that of a highly mobile population migrating between inland and coastal locations. These datasets also reveal that indigenous coastal groups practiced a seasonal schedule for exploitation of particular foods, possibly as a strategy to maximize returns (Parsons, 2012) or as a result of the reorganization necessary for sedentary groups described by Kelly (1998).

Prehistoric Environment

Consonant with the characterization of migratory Late Archaic peoples has been an underlying assumption that the coast was inhospitable at certain times of the year. As a consequence, prehistoric groups were thought to engage in a seasonal round that brought them to the coast for shellfish exploitation and returned them inland during other seasons. Data from faunal analyses and the material culture present in coastal sites strongly suggest that coastal people annually exploited the resources of estuarine environments—salt marsh, tidal creeks, and tidal rivers—and were not seasonally migratory. The low frequency of lithic artifacts and debitage in most coastal middens, particularly in Late Archaic shell rings, suggests that inland resources such as chert were not abundant among coastal populations. If groups were practicing an inland-to-coast annual round, more lithic materials would be expected. The masses of invertebrate fauna and the taxa identified in these coastal sites indicate a primary emphasis on the shellfish, fish, turtles, and crabs of the estuary and a secondary emphasis on terrestrial vertebrate fauna.

Our understanding of the role that climate change has played in prehistoric times has grown in the past 40 years. Sea level rise, changing patterns of moisture and drought, temperature fluctuations, and the impact that these factors have had on coastal environments are issues of current concern and research (e.g., Bishop, Rollins, and Thomas, 2011). The addition of dendrochronological data from bald cypress may provide insights that will assist in modeling the kinds of challenges faced by coastal peoples (Blanton and Thomas, 2008). At the present time, however, the available dendrochronological record does not extend to the Late Archaic.

Several recent assessments of human impacts on coastal resources warn that we should expect significant and extensive human impacts on the prehistoric coastal environment and fisheries (e.g., Jackson et al., 2001; Erlandson and Rick, 2008). Reitz (2004) has shown how human fishing in the coastal strand has diminished the fisheries over time. Today we look at the maritime forests of the barrier islands and coastal margins and imagine Late Archaic people in these environments. Given the plantation history of the barrier islands and coastal zone, however, most of these areas have been cleared extensively and are now reforested. In prehistoric times, it is more likely that substantially cleared expanses were created by coastal people because of the need for wood in building, cooking, heating, transportation, lighting, and many lesser technological uses such as snares, traps, arrows, spears, paddles, and mortars. Grasses and palm fronds would be needed for thatching, cordage, thread, matting, and bedding. Areas for canoe fabrication as well as launching ways, repair, and storage should be expected. A system of weirs in the tidal creeks, of increasing size and complexity relative to the size of the tributary, could sustain coastal populations.

Technology

Given the evidence for sedentism and the adaptation to coastal hunting, gathering, and fishing, the material inventory of these groups must be anticipated to focus technology to these needs. In an early study of freshwater river-corridor adapted people in Guiana (Roth, 1924), a majority of the technology, including basketry traps, cordage, arrows, harpoons, and many other items were fabricated from perishable materials. The absence of quantities of lithic material suggests that coastal people in the Georgia Bight made a similar adaptation. Sedentary occupants of the coastal zone probably obtained food from many, if not all, of the biotopes available to them. Procurement strategies likely included constructing weirs in the tidal creeks and rivers; fishing from canoes with spears, harpoons, arrows, leisters, or lines; hunting on the marsh islands and mainland; and gathering plants and invertebrates. Although direct evidence of fishing technology is meager—perhaps we recover only the small bipointed bone segments used as fish gorges—indirect evidence of netting capture or spearing can be gained from study of the sizes of fish in the collections (Colaninno, 2011). Estimates of fish size (length) suggest that a variety of sizes were being taken with concentration on smaller fishes. Although canoes were available (Wheeler et al., 2003), there is no evidence of offshore fishing.

Social Behavior

In this overview, we have two basic types of sites: shell rings and shell middens. Shell rings are primarily a Late Archaic phenomenon but ring-shaped middens (with black earth and shellfish) are known from Florida during the Woodland Period (e.g., Bernath—8Sr986 and Bird Hammock—8Wa30) (Bense, 1969, 1998; Penton, 1970). Shell rings are annular accumulations of food debris, broken pottery, occasional lithic materials, and occasional nonarticulated human remains. They are associated with the earliest ceramics in North America, the fiber-tempered series. The kind of social organization among these people is unknown, but the probability of sedentary life has suggested to many that the egalitarian social structure of truly migratory bands cannot be imputed to these people. The term transegalitarian has been suggested by Clark and Blake (1994) and Hayden (1995a) to describe societies that are somewhere between egalitarian and politically stratified. This term may be a good descriptor for sedentary Late Archaic people who occupied the Georgia Bight.

The function of shell rings has been a subject of contention for archaeologists for several decades. Recently, arguments regarding ring function have taken three primary stances: (1) shell rings represent monumental architecture and are the product of feasting and other ceremonial events; (2) shell rings represent the accumulation of daily refuse; (3) shell rings are the result of a combination of both quotidian and ceremonial accumulations. Our current lack of housing structures associated with shell rings confounds the issue of ring function. Although archaeologists have identified pit features and postmolds inside several shell rings using remote sensing (e.g., Sanger and Thomas, 2010), housing structures remain elusive. If, as some believe, the habitation was internal, we may be seeing all of the living debris—whether ceremonial or daily—deposited around an interior structure or structures. Thompson and Andrus (2011: 336) include a depiction of dwelling structures inside a ring, but the relationship of shell-bearing deposits and residential areas is currently unknown. If refuse were not deposited around a circular arrangement of structures, then we must agree that the refuse was intentionally disposed in a circular manner. It was not a rectangular deposit, nor square, but intentionally circular. This deposition pattern repeats along the Atlantic coastal zone in the Late Archaic Period more than three dozen times.

Shell middens are deposits of refuse that are the result of both quotidian and ceremonial activities. Rather than viewing these middens as monumental, most archaeologists view midden deposits as food refuse, with residential structures located in the immediate vicinity. The effective distance that people take their refuse for disposal is unknown, but Milanich’s (1973) description of a Deptford Period site on Cumberland Island indicated that the midden was immediately adjacent to the residence.

DISCUSSION

Since the 1970s, a sizeable database of samples from sites in the Georgia Bight has been generated, primarily by long-term research projects directed by museums and academic institutions. It is clear that this research has added to our understanding of prehistoric lifeways from Late Archaic times through the Mississippi Period. Zooarchaeological data and archaeobotanical data (of which we have far less) have provided insights regarding diet, subsistence strategies, seasons of site occupation, technological requirements, and environmental focus. As a result of our site assessments, we can also see areas where more work is needed.

One of the greatest needs is evidence of house types and housing arrangement in the coastal strand. At the present time, our data are meager. Over the years, there has been argument about whether habitations were located atop, inside, or outside shell rings and on or adjacent to middens. Early archaeologists focused on midden deposits and gave far less attention to the inside of the midden or its surrounding area. There has been a perception that the midden is the site rather than that the midden is one element of a site. Field experiments at Hatchery West showed that evidence of Mississippian house patterns lay apart from household midden deposits (Binford et al., 1970). However, expanded excavations and shovel-test surveys surrounding the Late Archaic shell rings on St. Catherines Island have not identified residential structures thus far.

Another long-standing issue is the absence of skeletal remains in Late Archaic shell ring sites. C.B. Moore (1998 [1897]: 159) recovered human remains in Sapelo Ring I and commented that it was not from an articulated burial. Since that time similar observations have been made elsewhere (Marrinan, 1975). Precisely what these human skeletal remains represent is unknown, but they may be evidence of ancestor veneration, discard of human remains that were considered unimportant, or even cannibalism. To date, articulated burials are lacking from Late Archaic shell ring sites but they are not uncommon in some midden sites throughout the Southeast (e.g., Indian Knoll, Tick Island).

The possibility of migration from another area remains the elephant in the room for some of us. While we marvel that Oceanic colonizers sailed across vast stretches of open ocean to settle the islands of the Pacific, we must not overlook the settling of the Caribbean. As Rouse (1992) has reminded us, it was not wholesale colonization, but rather waves of settlement occurring at varying distances over many years. We do not know whether Florida and the southeastern Atlantic coast figure into the spread of people from South and Central America as Ford (1969) contended. As the techniques of DNA sequencing become less expensive and more effective, we approach the time when genetic profiles for contemporaneous coastal and inland populations may be obtained. It may become possible to respond to Ford’s hypothesis.

Also clear to us is the need for CRM firms to generate floral and faunal data from the projects they undertake, and to publish these data widely. Today, CRM firms undertake more archaeological investigations than all other segments of the archaeological community. The publication of detailed faunal analyses from CRM projects has the potential to greatly increase our understanding of subsistence in the Georgia Bight. Standardization of screen size to 1⁄8 in. or smaller, as well as the quantification of at least some portion of the invertebrate remains, would provide datasets that are more comparable in their representation of the assemblage.

Worked bones are a common midden inclusion, but many archaeologists regard worked bones as “artifacts” and remove these specimens from the faunal sample. Thus the faunal analyst does not see these specimens and cannot include them in the analysis of the assemblage. There is controversy regarding how worked bones should be treated in faunal analyses because elements such as antlers and teeth are commonly modified. In Florida, it is not uncommon to find shark teeth that have been drilled, notched, or show evidence of use-wear. Most analysts separate these specimens and exclude them from biomass estimates. Bones such as the metapodials of white-tailed deer, which were commonly modified for the production of tools, represent primary food resources and secondary use as tools. Elements that were commonly used to make bone tools may be underrepresented in faunal assemblages as a consequence of removing worked bone. As such, the biomass estimates for particular species may be underestimated.

Faunal analysts remain concerned about obtaining representative samples. Column sampling should not replace the recovery of larger samples such as block excavation assemblages. Certainly it is cheaper to take column samples and ignore the remains in general levels, but this practice results in a biased view of the taxa present and their relative significance in the collection. It is true that we typically excavate only a small percentage of a site; this further constricts that percentage to a 50 × 50 cm column or less and cannot assure the recovery of a representative sample. This is particularly true for large coastal sites that were occupied over centuries or include multiple phases of occupation. In some instances, the practice of subsampling column samples (e.g., selecting certain levels or areas) results in even less representative data.

Forty years later, we can measure our progress in the quality of samples recovered from field projects and the data generated by analysis. We also can see that insights regarding the behavior of people in the coastal zone have suggested more complexity than traditionally attributed to Late Archaic groups. Older attitudes about the feasibility of life in the coastal zone have been challenged by this work and healthy debate has flourished. After 40 years of development in the field of zooarchaeology, “archaeologists have a well-stocked arsenal of methods and techniques available for reconstructing the past subsistence activities” (Thomas, 2008: chap. 12, 306).

Figure 2.1. Estimated biomass contribution for mammals (in ascending order). Abbreviations: FOY SJII, Fountain of Youth, St. Johns II Period; JAX Electric, Jacksonville Electric Authority; Devil’s Walk, Devil’s Walkingstick; Cathead W, Cathead Creek, Woodland Period; Sapelo III, Sapelo Shell Ring III; FOY LA, Fountain of Youth, Late Archaic Period; Cathead M, Cathead Creek, Mississippi Period; Kinzeys, Kinzeys Knoll; Bluff, Bluff Midden; McQueen, McQueen Shell Ring; Bourbon, Bourbon Field; St. Cath Ring, St. Catherines Shell Ring (Reitz, 2008, and Colaninno, 2010, data); South End, South End Mound I.

Figure 2.2. Estimated biomass contribution for birds (in ascending order).

Figure 2.3. Estimated biomass contribution for reptiles (in ascending order).

Figure 2.4. Estimated biomass contribution for fish (in ascending order).

Figure 2.5. Graph of the faunal density using biomass estimates (in ascending order) for samples that were obtained from at least one cubic meter.

TABLE 2.1. Faunal Density Using NISP, MNI, and Estimated Biomass

Faunal density calculations using NISP, MNI, and estimated biomass are ranked in ascending order; rank 1 has the highest density and 6 has the lowest. Note that the ranks for each site are not always identical.

Site

Screen (in.)

NISP/m3

Rank

MNI/m3

Rank

Biomass
(g/m3)

Rank

Cannon’s Point

1⁄8

1574.2

6

26.5

6

1392.0

6

West Ring

1⁄8

3399.3

4

89.3

3

2212.9

5

Grand Shell Ring

1⁄4

7201.3

2

133.0

2

9482.8

4

Grant Mound

1⁄4

3857.2

3

69.7

4

9897.2

3

Bluff Midden

1⁄4

2719.2

5

54.8

5

11,881.2

2

Kinzeys Knoll

1⁄4

8157.8

1

134.7

1

25,566.1

1

TABLE 2.2. Faunal Density Calculations

Faunal density is calculated using estimated biomass (in ascending order of biomass per cubic meter) for each of the sites with at least one cubic meter of excavated and analyzed material.

Site

Period

Screen (in.)

Biomass (g)

Excavated Volume (m3)

Biomass

(g/m3)

South End

Mississippi

1⁄8

16,082

54

297.8

Cannon’s Point

Late Archaic

1⁄8

18,096

13

1392.0

West

Late Archaic

1⁄8

6196

2.8

2212.9

St. Catherines Ring

Late Archaic

1⁄4, 1⁄8

59,541

14.4

4134.8

Grand

Mississippi

1⁄4

123,276

13

9482.8

Grant

Mississippi

1⁄4

64,322

6.5

9897.2

Bluff

Mississippi

1⁄4

29,703

2.5

11,881.2

McQueen

Late Archaic

1⁄8

15,704

1.2

13,086.7

Kinzeys

Mississippi

1⁄4

85,011

3.2

25,566.1

CHAPTER 3. Archaeological Geophysics on St. Catherines Island: Beyond Prospection

Ginessa J. Mahar[5]

Introduction

Geophysical instrumentation was first used on St. Catherines Island in May of 1981 (Garrison, Baker, and Thomas, 1985: 299) during the search for the once-lost Mission Santa Catalina de Guale. At the time, this method of archaeological investigation was still in its infancy. Very few archaeological projects had the proper access, funding, personnel, or foresight to include still-underdeveloped methods of prospection. The unrealized potential of geophysical prospection would not last for long, however. In the more than 30 years since Mission Santa Catalina de Guale was discovered, great advances have graced the field of archaeogeophysics, specifically in regard to the collection, processing, display, and analysis of geophysical data (Wynn, 1986; Clark, 1990; Brizzolari et al., 1992; Juppenlatz and Tian, 1996; Cammarano et al., 1998; Piro, Mauriello, and Cammarano, 2000; Vafidis, Economou, and Sarris, 2002; Kvamme, 2003b; Neubauer, 2004; Johnson, 2006; Kvamme, 2006a; Wiseman and El-Baz, 2007; Aspinall, Gaffney, and Schmidt, 2008; Campana and Piro, 2009). Instrumentation has become more sensitive and easier to use with software that is approachable, even for the novice. The computer graphic interpretation of geophysical data has become commonplace in archaeology, and most archaeologists today are accustomed to viewing the results of a geophysical survey in color scale or contour maps, as opposed to crude printouts with no sense of spatial reference. More importantly, these graphics are able to be georeferenced so that they are linked in real space in a GIS platform, allowing the results to be overlaid with many other lines of investigation, such as topographic mapping and excavation. Even more remarkable is that survey, processing, and display can take place all in the same day.

The tremendous success of the geophysical surveys at Mission Santa Catalina encouraged David Hurst Thomas to continue with geophysical surveys on St. Catherines. In the years to follow, the mission Pueblo (9Li8, 9Li13, 9Li274), Back Creek Village (9Li207), Meeting House Field (9Li21), the St. Catherines Shell Ring (9Li231), and the McQueen Shell Ring (9Li1648) were all surveyed geophysically, which was no small feat considering the sheer size of these sites. Over the course of investigating these sites, the motivation and benefits of geophysical survey have changed little: gain as much information as possible from the sites and do it in the most responsible way. Taking to heart the island creed of “Research, Education, Conservation,” Thomas has developed a program of geophysics in conjunction with excavation on St. Catherines that has benefitted more than just the archaeology of the island (the research). This course of investigation has also helped to minimize the impact of destructive excavation (the conservation) and has provided wonderful opportunities for a plethora of promising young scientists (the education).

In his 1987 work, The Archaeology of Mission Santa Catalina de Guale: 1. Search and Discovery, Thomas proposed using midrange theory to better utilize geophysical data. He argued that a bridge needed to be built between empirically collected geophysical data and theoretical concepts in archaeology. Thomas and colleagues proposed establishing a library of geophysical signatures that align with archaeological features at Mission Santa Catalina de Guale. Although the data were never taken to that precise level in that study, the idea that geophysical signatures can be used to extrapolate and project archaeological information is an intriguing and, as this chapter will show, completely feasible concept.

Geophysics Today: Beyond Prospection

In his 2003 American Antiquity article, Kenneth Kvamme pointed out how archaeogeophysical surveys can contribute to lines of archaeological inquiry beyond prospecting for archaeological features to excavate. Advances in data collection and computer processing, strong research objectives, and proper data collection practices have led archaeogeophysics to take a turn from its traditional role in archaeology as a mere prospection tool (Kvamme, 2003a; Lockhart and Green, 2006; Lydick, 2007; Thompson, 2007; Gaffney, 2008; Mahar, 2008; Campana and Piro, 2009; Keay et al., 2009; Mušič et al., 2009; Thompson, Arnold, and VanDerwarker, 2009; Conyers, 2010; Conyers and Leckebusch, 2010; Leopold et al., 2010; Mol and Preston, 2010; Thompson et al., 2010; Hurley, 2011; Mahar, 2011a; 2011b; Masini and Soldovieri, 2011; Walker, 2012).

The current study agrees with Kvamme’s claim that archaeogeophysical data, when collected and applied properly, can be used as a primary source of data in the archaeological evaluation of a site. First, this study will examine the practices and criteria necessary to use geophysical data as primary archaeological data. Second, a bit of necessary background will be presented regarding the geophysical surveys conducted, after which the methods of data integration and display will be discussed. Next, specific examples regarding the geophysics of the shell rings will be detailed as evidence of the benefits of geophysical investigation, showing how the data can be used as a primary means of investigation. Lastly, conclusions and proposals for further research will be made.

Geophysical Data as Empirical Archaeological Data

Geophysical data can provide much more than a map of where to dig (Conyers and Leckebusch, 2010). The data generated, since they are based on measurements of observable physical properties, are strongly tied to the basis of empirical research, especially when collected under a well-organized research design (Clark, 1990; Aspinall, Gaffney, and Schmidt, 2008; Conyers and Leckebusch, 2010). Geophysical techniques provide the ability to measure the physical properties of the ground below the surface in a scientific manner. Depending on the technique or techniques being used, geophysical investigation provides firsthand, observable data that speak of the characteristics of the archaeology underfoot, much like various other data acquisition techniques in use today. As such, the data gathered can be taken into consideration much like geomorphology, soil chemistry, radiocarbon testing, soil and sediment analysis, and stable isotope analysis are, to name a few. Though using geophysical survey solely as a prospection technique is tremendously useful, it hinders the potential application of the data. This chapter will attempt to use middle range theory to approach geophysical evidence, using signatures as direct archaeological evidence, instead of as an intermediary on the way to excavation. There are two major criteria for using geophysical data as archaeological empirical data as far as this study is concerned. The first is a multiple means approach that is executed with strict collection standards using appropriate instrumentation for the area under investigation. The second is that data must be tested with appropriate excavation strategies under a well-planned research design, and the results may then be extrapolated and projected across the site.

To do this, this chapter will look at both the novel and complementary characteristics of geophysical datasets. A novel, or unique, dataset is one that provides information that cannot be gleaned in any other way. For example, the only way to determine the magnetic properties of a site is to conduct a magnetic survey. Magnetic data provide information that can be used to identify locations of thermal activity and biogenetic processes, as well as applying the amplitude to speculate on temporal association (Kvamme, 2006b). A complementary dataset is one that serves to enhance other datasets, providing additional information that will lead to a more thorough assessment of the data as a whole. For instance, a soil resistance survey can provide information on the conductive characteristics of the soils, but without mapping the vegetation or knowing the geology of the survey area, false conclusions may be made regarding the results.

Geophysical datasets not only allow us to determine where features of interest are beneath the surface of the soil, but also provide information that may help us to determine what those things are. A dataset with such potential would be tragically undermined if it were used merely for the purpose of locating sites or as a locator for destructive excavations. Recent work in the field has shown the various ways that geophysical information and assessment can stand alone as archaeological interpretative elements (Martin, Bruseth, and Huggins, 1991; Linford and Canti, 2001; Weston, 2001; Ambos and Larson, 2002; Dalan and Bevan, 2002; Thacker, Ellwood, and Pereira, 2002; Olson, Jones, and Lang, 2004; Persson and Olofsson, 2004; Sarris et al., 2004; Jones and Maki, 2005; Jones and Munson, 2005; Maki, 2005; Persson, 2005; Bevan, 2006; Conyers, 2010; Leopold et al., 2010; Moffat et al., 2010). By using geophysical data properly, we can enrich the overall assessment and interpretation of archaeological sites.

Multiple Means Approach: A multiple means approach dictates utilizing multiple geophysical methods in conjunction with other remote sensing techniques to enhance a geophysical dataset (Brizzolari et al., 1992; Piro, Mauriello, and Cammarano, 2000; Clay, 2001; Thompson et al., 2004; Kvamme, 2006a; Kvamme, Johnson, and Haley, 2006; Kvamme, 2007; Lydick, 2007; Keay et al., 2009; Watters, 2009; Leopold et al., 2010). By employing different techniques that are based on varying geophysical principles, a multiple means approach will pick up previously undetected subsurface features while simultaneously creating stand-alone measurements. This may also provide a double-check system of complementary techniques by informing the surveyor as to the various characteristics of the detected geophysical features (otherwise termed geophysical anomalies). A case in point is the earlier example provided regarding the effects of vegetation and soil resistance readings.

Individual datasets can then work together to create a network of datasets, lending further confidence to any one technique. The combination of multiple lines of geophysical data and other remote sensing information is referred to as data fusion and has been the topic of several recent articles and theses (Kamei et al., 2000; Kvamme, 2003a, 2006a; Watters, 2006; Kvamme, 2007; Lydick, 2007; Gaffney, 2008; Keay et al., 2009).

In this study, the two types of geophysical techniques utilized were soil resistance and gradiometry. These methods were used in conjunction with topography, probing, vegetation mapping, coring, and excavation.

Excavation and Extrapolation: With a background in the archaeology and geology of a region, specific geophysical signatures can be tested, and the findings can be projected across the site with relative confidence. Through minimally invasive subsampling of detected geophysical features, a solid archaeological interpretation can be elucidated and large, destructive investigations can be minimized (Kvamme, 2003a). This method of excavation and extrapolation has become a major influence in landscape archaeology because it can ensure that the maximum amount of information is gained from geophysical and archaeological investigations (Martin, Bruseth, and Huggins, 1991; Kvamme, 2003a; Abdallatif, Mousa, and Elbassiony, 2003; Conyers, 2010; Gaffney, 2008; Mušič et al., 2009; Powlesland, 2009; Leopold et al., 2010; Masini and Soldovieri, 2011; Walker, 2012).

The examples in this chapter show how a program utilizing geophysical survey in tandem with standard archaeological testing, such as excavation, greatly improves both the quantity and quality of data obtained in the field while aiding tremendously in the postfield interpretation of information.

Background

The two case studies discussed here are drawn from work on St. Catherines Island (see fig. 3.1). St. Catherines Island is a barrier island on the Georgia coast composed of well-drained sands. Holocene beaches surround a Pleistocene core that has given rise to a very fruitful environment, including many intertidal channels, estuaries, shellfish beds, and maritime forests that have continually provided for human subsistence for more than 4000 years (Linsley, Bishop, and Rollins, 2008; Thomas, 2011a).

During the Late Archaic Period (3000–1000 b.c.), the stabilization of sea levels formed the barrier islands we know today as the Golden Sea Islands, which stretch from New Jersey to Florida (Linsley, Bishop, and Rollins, 2008). It was also during this period that shellfish beds took hold and began to form the estuary environment with which we are familiar. The first people to take advantage of these new developments were the Late Archaic people (Reitz et al., 2010: 49). Shortly thereafter, shell middens began to appear along the marsh edges of the island and, soon after that, the Late Archaic shell rings were formed (Sanger and Thomas, 2010: 47).

Shell ring sites have been identified and researched for more than 100 years, but it wasn’t until the 1970s that they began to receive the inquiry and consideration they deserve (Waring, 1968; Waring and Larson, Jr., 1968; Hemmings, 1970; Marrinan, 1973, 1975; Trinkley, 1975; Crusoe and DePratter, 1976; Trinkley and Ward, 1978; Trinkley, 1985). Shell rings are composed of mounds of shell often arranged in a circular or semicircular configuration with little or no shell on the interior or exterior (see fig. 3.2). Their height can vary from 1 m to 6 m and they can be up to 250 m in diameter (Russo, 2006: E, 8). Russo (2006) discusses a thorough range of conventional dates for shell rings and argues for their historic preservation. Dates ranging from 4600 b.c. to 1635 b.c. have been gleaned from both shell and charcoal assays (Russo, 2006: E, 11–17). Although the shell dates in many cases are not corrected for reservoir effects, the point is to show the wide temporal period in which shell rings are present on the landscape. Shell rings have been located along the coastlines of Florida, Georgia, and South Carolina, and regional variations can be seen in figure 3.2. Florida’s shell rings tend to be of the C-shaped variety and consequently can be much larger than the circular, closed contexts of those found in Georgia and South Carolina. It has been postulated that this difference in form may be related to a difference in function. A C-shaped construction may facilitate community growth, unlike that of a closed circle that would not as easily expand out to support larger populations (Russo, 2002: 90).

Current Theories Regarding Shell Ring Formation

There are four major theories that explain shell ring formation and they will be briefly outlined here. The gradual accumulation model postulates that shell rings are the result of several individual house middens arranged in a circle, which have coalesced into a solid “ring” of continuous shell deposit (Trinkley, 1985; Russo, 2002; Russo and Heide, 2003; Thompson, 2007). The circularity of the residential pattern may or may not reflect an egalitarian system of social organization; this idea will be elaborated upon further in this section. A second hypothesis is that periodic feasting events could explain the shell accumulation in such a conspicuous formation (Saunders, 2004a; Thompson, 2007). Intentional or ceremonial mounding by singular groups or coalitions is offered as a reason for shell ring construction, either to mark a special place on the landscape or to form a bond among often dispersed members of a larger society (Russo and Heide, 2003; Saunders, 2004b; Saunders and Hays, 2004; Thompson, 2007). A third theory of ring formation combines the two former theories where shell rings are considered social spaces, where inequalities begin to emerge, and where consumption changes from mere function toward a role involving ceremony and display via higher status locations (Russo, 2004; Thompson, 2007). A fourth developmental model is based on Binford’s theory that the function of sites may change over time (Thompson, 2007). Thompson posits that the rings started out as purely functional residences, albeit in a circular pattern, and then at some later point in time they became more ceremonial in function when the ring grew to a point where it was considered “monumental,” perhaps following the earlier theory of conspicuous consumption (Thompson, 2007). Many questions remain regarding the purpose of circular and arcuate ring construction, and it seems that many sites contain unique occupation histories that should be considered independently of one another. The following analysis will provide background on the geophysical surveys conducted and offer an examination of the geophysical and excavation data of the two shell rings on St. Catherines Island.

Geophysical Surveys

The geophysical surveys of the two Late Archaic rings on St. Catherines were conducted over various field seasons from 2006 through 2009. Site preparation consisted of clearing vegetation that would interfere with the normal, comfortable operation of the instrumentation, such as thick palmetto patches or tangled vines. Trees were only cut down if they exhibited signs of decay or fungus and were deemed a hazard to the surveyors due to their instability. Grid corners were shot in using a laser total station and marked with plastic orange stakes. One-meter intervals along the east-west transects were marked with plastic pin flags for ease of survey. North-south transects were marked using ropes that were held by survey personnel called jockeys. Each rope had 0.5 m or 1 m marks for the surveyor to follow. All topographic data were collected with a laser total station in a systematic fashion. Additionally, probe surveys were conducted at each ring whereby a metal probe was inserted in the ground to test for shell density. A scale of 1 to 5 was used (5 indicating impenetrable shell and 1 indicating a shell-free area) and surveyors were kept consistent as a control.

St. Catherines Shell Ring: The St. Catherines ring magnetic data were collected in bidirectional fashion with a G858 cesium vapor gradiometer at 1 m wide traverses using a 10 m marker along each north-south transect. Thirty-six 20 m² blocks were surveyed for this project, collecting 7600 m2 of data. The soil resistance for the site was collected using a Geoscan RM15-D for efficient data collection. The use of the multiplexer allowed us to survey in 1 m wide traverses while collecting 0.5 m traverse data. Sample intervals were 0.5 m, amounting for 40 readings per line. The same 36 blocks were surveyed as with the gradiometer.

McQueen Shell Ring: The McQueen ring magnetic survey was conducted using a Geoscan FM256 fluxgate gradiometer in a bidirectional fashion, only this time using 0.5 m traverses and 1 m spatial markers within the 20 m grid system. The difference between the magnetic instrumentation used at each site has been studied and is elaborated upon by Mahar (2010). Briefly, we examined the differences between the two gradiometers by resurveying the St. Catherines Shell Ring with the FM256. By having results from the same instrument from each site, we were able to compare the results of the two rings directly. By doing this, we were able to alleviate concerns that we may have achieved dissimilar results due to the change in equipment. The soil resistance data were collected in the same fashion as the soil resistance at the St. Catherines ring.

Data Integration and Display

The goal of data integration and display is to cross correlate numerous remote sensing datasets such as soil resistance, magnetics, topography, shell density, and the like. All the above techniques gather very different types of data and by overlaying them, we can learn more about the specific information each method is relaying. The technique of overlaying geophysical and topographic data has been used in various publications (Brizzolari et al., 1992; Juppenlatz and Tian, 1996; Cammarano et al., 1998; Vafidis, Economou, and Sarris, 2002; Neubauer, 2004; Johnson, 2006; Kvamme, 2006a; Venter et al., 2006; Lydick, 2007; Wiseman and El-Baz, 2007; Aspinall, Gaffney, and Schmidt, 2008). By integrating the St. Catherines datasets by site, we hoped to reach better-informed conclusions regarding the identification and distribution of archaeological features.

Data Integration Concepts and Methods

Over the last few years, as computers have become better incorporated with archaeological investigative techniques, methods allowing for better integration of data drawn from both prospection and excavation have been developed. Among these, computer-based mapping programs are perhaps the most widely used and more approachable technologies. Programs such as Surfer and ArcGIS have aided tremendously in the overall synthesization of archaeological data. Computer graphic programs such as those mentioned can help to reconstruct three-dimensional images of stratigraphic layers, display the distribution of cultural materials and anthropogenic features, calculate densities, averages, means, ratios, and standard deviations of artifact occurrence, and apply topographic data to the comparison of all the above.

The integration methods presented here are based on interpretive and computer graphic data integration and analysis consisting of visual interpretation, vectorization, two-dimensional overlays, and translucent overlays. By overlaying two or more of these graphic representations of geophysical data, the archaeologist can simultaneously evaluate multiple investigative methods. Traditionally, geophysical data are processed and analyzed separately and are often written up in completely separate reports. Here, however, multiple georeferenced overlays are possible, allowing the data to be visualized at once, which provides a more holistic display of information.

Georeferencing is defined as the process of fitting geophysical data or data images into their correct physical place within a display plane (Aspinall, Gaffney, and Schmidt, 2008: 141). The display plane used for the body of analysis within this work is ArcMap, a component of ESRI’s ArcGIS suite of geospatial processing programs. The benefit of georeferencing geophysical datasets is the ability to accurately overlay multiple sets of information. If all data are collected systematically using the same coordinate system, they can be matched up using their geospatial coordinates. This then allows the point-specific analysis of multiple datasets (Juppenlatz and Tian, 1996; Vafidis, Economou, and Sarris, 2002; Neubauer, 2004; Kvamme, 2006a, 2006c, 2007).

All grid mapping, shell density distribution, elevation, metal prospection, topography, and vegetation mapping were completed with a laser total station based on a site datum connected to UTM coordinates. Knowing the locations of potential unwanted influences, such as historic metal, certain types of vegetation, or sharp increases in elevation, will add to the accurate interpretation of geophysical datasets. Likewise, the overlay of satellite imagery and mapping of topographic elements, such as tree lines and marsh edges, helps to put the data in the perspective of the landscape in which it resides.

Figure 3.3 is a plate of some of the datasets used in the interpretive analysis of the geophysical data from the St. Catherines Shell Ring (9Li231). These data were overlaid as layers using ArcGIS and evaluated for archaeologically significant geophysical features. Areas of interest that pertained to the temporal period under investigation were then graphically drawn in or vectorized using ArcGIS, see figure 3.4 (Kvamme, 2007).

archaeological interpretations of shell ring geophysics

This section will directly compare the four major areas of the two Late Archaic shell rings on St. Catherines Island (the ring exterior, the shell midden, the interior edge, and the interior of the ring) by using the analyzed geophysical data in conjunction with evidence from recent excavations. The discussion will focus on those areas that pertain to the topic of this chapter, geophysical survey as a substantive line of direct archaeological investigation, as there is not enough room in this volume to expound all aspects of these complex, intriguing sites.

The Ring Exterior

The geophysical surveys of each ring incorporated portions of the area outside the shell rings. Along the marsh-facing edges of the rings, survey was executed all the way to the marsh edge and along the interior-facing edges, survey was carried out anywhere from 20–70 m away from the rings’ edge. The intention here was twofold. First, it was important that we obtain information regarding what a “normal” or nonring background signature would look like to appreciate the differences caused by the presence of the shell ring (Gaffney, 2009). Second, the area around the shell rings, or exterior ring area, has not been thoroughly explored in previous archaeological investigations, until recently (Thompson, 2007).

Both the resistance and magnetics produced lucrative results along the exterior perimeter of the shell rings on St. Catherines Island. Overall, both surveys showed there were fewer geophysical anomalies outside the ring than within the midden or in the interior shell-free plaza. However, the geophysical signatures that are present have begun to challenge what little we do know about the exterior zone of shell rings. Michael Trinkley (1980) briefly discusses what he believes the exterior of shell rings should contain based on his excavations at Lighthouse Point and Stratton Place in South Carolina. According to Trinkley, there should be an area of debris scatter consisting of potsherds and animal bones 10–15 ft from the exterior edge of the ring. Outside this zone, evidence of human occupation drops significantly, artifact density decreases, and soil chemicals indicating occupation become negligible (Trinkley, 1980). Trinkley concludes that the primary occupation and activity at the rings must have occurred either on top of or inside the rings.

Figure 3.4 shows the vectorized results of the geophysical analysis of both the soil resistance (blue) and the magnetic data (green) in conjunction with data from our systematic shovel test pit surveys that were conducted outside each of the shell rings. In each case, the geophysical signatures occupying the exterior of the rings are fairly large and, in many cases, characterized by geometric forms. The resistance signatures at both rings consist of both circles and polygons of yet unknown associations. Square habitations are common in southeastern aboriginal archaeology, though most of these appear during later temporal periods (Steponaitis, 1986; Scarry and McEwan, 1995). However, Sassaman and Ledbetter relate that evidence for both circular and rectangular structures has been identified in the Middle and Late Archaic periods (Sassaman and Ledbetter, 1996: 87). What is currently lacking is a substantive work on such architecture, as both ephemeral and more permanent structures have been identified but little speculation has been raised as to what the shape, size, and durability of these structures could offer to theories of community patterning and organization.

Although no large excavations have been placed in the exterior zone of either ring on St. Catherines Island, the results of the shovel test pit survey point to a Late Archaic association for at least a few of these geophysical features. Shovel test pits alone could not have provided enough information to surmise that there is the potential for Late Archaic structures within the area immediately outside the shell rings. Trinkley and Ward, in their investigations at the Lighthouse Point Shell Ring, involved chemical testing across and along the exterior of the site; pH, phosphorus, potassium, and calcium were all tested (Trinkley and Ward, 1978). They found that considerable activity occurred outside the ring, although there was a lack of shell and pottery indicating to them that these were not occupation areas (Trinkley and Ward, 1978: 71). Conversely, Thompson’s investigations at the Sapelo Island shell ring complex have shown through geophysical investigation and excavation that there were indeed occupations outside the rings that either predate or just postdate the major occupation of the rings themselves, if they are not contemporaneous (Thompson, 2007).

To date, minimally invasive geochemical and geophysical techniques have led to the majority of information we have regarding the activity patterns along the exterior of shell rings. Results such as those produced by geophysical survey or geochemical testing, although not as tangible as structural or artifactual material, cannot be discounted in the research regarding the use of the exterior areas of the shell rings. Ignoring such evidence could unfairly bias the archaeological interpretation of this intriguing and understudied activity area. Additionally, such evidence (for example, the mapping of geophysical features) can be used in hypothesis development, broadening the base by which we approach anthropological questions.

The Midden

The St. Catherines and McQueen shell rings exhibit very different archaeological and geophysical characteristics regarding the primary shell deposit. At the most fundamental level, although similar in diameter and shape, the characteristics of the shell-heavy deposits diverge to almost opposite ends. While the St. Catherines Shell Ring is composed of predominantly whole oyster, intermixed with various other whole molluscs, crushed shells, and very little soil matrix (see fig. 3.5A), the McQueen Shell Ring is composed of whole and crushed shell (still predominantly oyster) interspersed with a matrix of highly organic soil (fig. 3.5B). The following discussion will detail the observed archaeological characteristics of the shell deposits as they apply to the geophysical surveys conducted.

The geophysical signatures present within the midden portion of the shell rings offer insights into formation processes and postdepositional occurrences in addition to helping to identify and interpret activity areas (Thompson, 2007). In the case of the magnetics, there are instances where the collected data are affected by historic influences; the Late Archaic signatures can be obscured by the introduction of ferromagnetic objects or the disturbance of the soil such as by plowing or boundary ditch construction. On the other hand, there are cases where these strong dipolar anomalies cannot be explained by historic interference. To complement our geomagnetic data, we surveyed systematically with a metal detector and laser total station, mapping in any modern or historic metal instances and any changes in elevation. These data can then be used to evaluate the detected magnetic signatures, helping to determine their association with the prehistoric component of the site.

Excavation evidence has been paired up with one of these instances in a test unit along the northern edge of the St. Catherines Shell Ring. Area N789 E801 (fig. 3.6), although excavated prior to any geophysical survey, corresponds to a series of magnetic gradient features (see fig. 3.6A for location). This particular area, in terms of the magnetic gradient results, comprises a series of dipolar signatures that may suggest discrete burning episodes. Features similar to these are common along the shell-heavy portion of the ring as can be seen in figure 3.6.

Not every instance of magnetic variation needs to be excavated, however. What we can project from this particular instance is that there are multiple burnings across the shell midden portion of these sites. These features appear to be small patches of burned shells that are commonly encountered in excavations along the ring. Multiple features of this nature can occur in a single 1 × 1 m excavated unit, and from what we can gather, the higher the density of burned patches, the stronger the magnetic signature. These burned patches do not appear to be heavily used fire pits but discrete burned areas. Although the exact function of these features is not known, from artifactual content, postholes and cooking pits may be unlikely explanations. Rebecca Saunders has suggested that similar features at the Rollins Shell Ring in Florida could have been steaming or smudge pits (Saunders, 2004a: 258). Additionally, burned shell and charcoal have been noted in the screens at the St. Catherines Ring; their presence is not always linked to the discrete burned patches, perhaps indicating extensive and repeated midden surface burning to aid in the decomposition process and vermin control (Meehan, 1982). This particular activity could explain the increase in low-amplitude magnetic activity on the shell midden that is not apparent in the nonmidden portions of the site.

As far as what this evidence means for theoretical interpretations of the rings, we return to Russo’s discussion of the second theory regarding shell ring formation, the ceremonial model. Russo postulates that ceremonial feasting episodes may result in fewer surface fires since the deposit is formed so quickly (Russo, 2004: 43). Along this line of interpretation, the frequency of geomagnetic signatures atop the shell rings may help to determine the potential for ceremonial activity at the shell rings. For further speculation regarding burning at shell ring and midden sites, please refer to Trinkley, 1980; Meehan, 1982; Stein, 1992; and Saunders, 2002a, 2004a.

Just as the magnetic data have helped to provide information regarding the potential activities and postdepositional processes occurring on the shell midden, the soil resistance data have helped to inform us regarding the formation process of the midden. In his 2006 dissertation, Victor Thompson discusses the patterning of resistance signatures as they pertain to the midden deposit of the shell rings on Sapelo Island. His findings at Ring III indicate that the ring is composed of discontinuous piles of shell (Thompson, 2006; 2007). According to Thompson, this arrangement of shell piles interspersed with occupational midden conveys that Ring III follows the gradual accumulation model of shell ring development (Thompson, 2007). The signatures from the rings on St. Catherines Island seem to follow a different pattern, however. There, at both sites, the resistance data reports that the densest portion of the shell midden holds a higher resistance than the edges and in some cases higher than the shell-free, well-drained interior. The densest portion in this case is also the highest portion of the ring; both factors add to the high resistance readings.

The resistance signatures combined with excavation evidence at the St. Catherines Ring show that there are pits and piles of shell all along the midden deposit, although none appears to be of an occupational deposit like Thompson defines at Ring III. However, the McQueen Shell Ring tells a different story. The resistance and excavation evidence indicates that the McQueen Shell Ring, unlike the St. Catherines Shell Ring, comprises crushed shell and organic soils much like the occupational midden that Thompson describes (Thompson, 2007). The presence of crushed shell has been mentioned in some literature associated with shell rings (Saunders, 2002a; Russo and Heide, 2002, 2003; Saunders, 2004a; Russo, 2004, 2006). The majority of researchers speculate that this comes as a result of trampling and compaction over the course of the use-life of the ring and most likely continues after abandonment. Opinions begin to diverge, however, once the duration of trampling and compaction is discussed. Antonio Waring and Lewis Larson, perhaps the first archaeologists to hypothesize on shell ring use speculate that,

[i]t would seem very likely that the shell ring was the site of many small habitations. The occupants apparently piled the rapidly accumulating shell beside their small dwellings; later they moved, and new shell was then piled on the former habitation site… (Waring and Larson, Jr., 1968: 273).

Here Waring and Larson are discussing Ring I on Sapelo Island. Trinkley has also offered that when shell rings were occupied, people were living on top of them, creating living spaces and surfaces atop the ring. He also suggests, from observations at Lighthouse Point, that when the ring got too tall, the occupants would level it off (Trinkley, 1980).

The amount of dark, organic sands within the matrix at the McQueen Shell Ring and the thinness of the deposit explain its low resistance values. Besides occupational midden as an explanation of leveling off, it may also be that there was a practice of capping the shell deposit with dirt periodically, either to facilitate habitation atop it or in a ceremonial fashion to mark the beginning or end of a session of deposition upon it (see Saunders, 2004a for further discussion on stratigraphic episodes at shell rings). Either way, the tremendous amount of soil present in the McQueen Shell Ring deposit is in stark contrast to the St. Catherines Shell Ring where the matrix involves a larger amount of whole shell and less dark organic sand in a much thicker deposit. Of all the remote sensing techniques conducted at the two rings, it was the soil resistance that best conveyed the difference between the midden portions of each ring, both on an inter- and intrasite basis. Excavation evidence reinforces this observation, and the combination of the two, in addition to the shell density data, has allowed us to pinpoint changes in shell matrix composition that have warranted further investigation.

Along both rings, there are areas of higher resistance and lower resistance that could have been caused by some of the activities proposed earlier, such as leveling, compaction, capping, or a combination of all of the above. Additionally, the evidence also suggests that very different use-lives and formation processes were present at each shell ring. Thompson speculated that shell rings may follow their own trajectories and their own formation histories (Thompson, 2007). The fact that the two shell rings on St. Catherines Island can be contemporaneous (Sanger and Thomas, 2010) and still so different when comparing the midden component is a testament to this statement.

In summation, the geophysical data helped detect unique areas along the deposit that we would not have known to investigate otherwise, such as differences between high and low resistance, that may lead to answers to questions regarding the unique depositional histories of the rings. These instances clearly demonstrate the advantages of integrating geophysical datasets with excavation and approaches like middle-range theory building. Here the data are valued beyond an X marking a spot; rather, they are used to project and assign viable interpretations to detected signatures.

The Interior Edge

Perhaps the most intriguing component of the two St. Catherines Island shell rings, both geophysically and archaeologically as far as this discussion goes, is the area along the interior edge of the midden deposit. Unquestionably, without the input from the geophysical surveys, we would be under very different presumptions as to the understood characteristics of this activity zone. Up to this point in the discussion, while the geophysics has enlightened us regarding various characteristics of the shell rings, the data have remained quite similar between the two rings. Here, however, the datasets begin to diverge. The magnetic gradient data at the rings have shown perhaps the greatest evidence of this. At the St. Catherines Shell Ring, there is evidence of a continuous magnetic “ring” feature along the terminal edge of the interior of the ring deposit, but a similar geophysical signature is not evident at the McQueen Shell Ring (see fig. 3.7).

The fact that the two shell rings do not share similar interior edge magnetic signatures suggests that the activities carried out in these areas were different. The excavations at the St. Catherines Shell Ring have uncovered several shell pit features that coincide with a dramatic change in the resistance signatures and the magnetic “ring” anomaly. This observation is significant when considering the previous discussion on ring formation. Similar pits have been identified at some, but not all, southeastern Late Archaic shell rings. In discussing the geophysics of the Sapelo Island shell rings, Thompson has determined that preexisting pits and individual piles serve as the basis for the formation of Ring III (Thompson, 2007; Thompson et al., 2010). These determinations have not been tested via excavation, however. The presence of prering pits has many connotations. At the outset of this chapter, multiple theoretical models for the creation of shell rings were introduced. Briefly, these were the gradual accumulation model, the ceremonial model, the dual function model (both gradual accumulation and ceremonial), and lastly the developmental model that states that the function and use of a place change over time. Thompson has determined that Ring III at the Sapelo complex was formed as a result of the gradual accumulation model for two reasons. First, the preexisting pits and piles show evidence that the ring was formed as a result of occupational middens interspersed with secondary refuse piles, and second, the archaeological material collected attests to the relatively domestic activities at the ring (Thompson, 2007). However, he does admit that all shell rings and similar sites will follow their own trajectories.

For instance, no archaeological evidence from the McQueen Shell Ring suggests that there are prering pits along the interior edge or under the main midden deposit. This is significant because it might explain why there was no interior “ring” anomaly detected in the magnetic data. Although excavations at McQueen found no evidence of prering pits, they did expose other characteristics that may help to determine McQueen’s placement within the above theoretical models. Trench N243 was excavated through the shell-heavy portion of the eastern midden deposit and continued west well into the shell-free interior of the ring. This trench, and subsequent block excavation, exposed a stratigraphic layer underneath the primary shell deposit, which has been described as a “clam floor.” This layer consists of a thin level of clam shells, lying with the interior face down. When fully exposed in the block excavation, this “floor” appeared to be about 4 m in diameter, and did not continue throughout the entire exposed block. Later it was discovered that a similar, but less distinct, layer also appeared within the western midden portion of the ring; however, this has not been further investigated beyond a 1 × 1 m unit, and therefore its status as a “floor” is currently undetermined. Beyond this, no other area at either the McQueen or St. Catherines ring has produced similar findings. The presence of this floor, and lack of prering pits, may suggest that McQueen falls under a different theoretical model of formation than the St. Catherines Shell Ring. A prepared floor as such could fall into the category of ceremonial construction (Saunders, 2002a; Russo and Heide, 2003; Russo, 2004; Thompson, 2007).

Certainly, if the interior ring signature we see at the St. Catherines Shell Ring is an effect of a series of early pits, then we are left to conclude that the lack of a similar signature or any physical evidence of pits at McQueen suggests that the gradual accumulation model does not fit at least as far as a linear evolution from pits to ring. The magnetic ring signature and the fundamental difference in construction, and perhaps usage histories, that led to the formation of each ring indicate very different trajectories for these shell rings. This is extremely significant regarding the theories of social organization and ring usage during the Late Archaic because of the fact that the rings appear to be contemporaneous (Sanger and Thomas, 2010). Sanger and Thomas (2010) discuss the dating of the ring in their chapter “The Two Rings of St. Catherines Island,” the first publication to document the recent work at both of the rings. They have correlated the radiocarbon dates from the excavations at both rings and have surmised that the major construction of both the rings occurred roughly 2250–2000 b.c., although the deposition at the McQueen Shell Ring may have continued for another 50 years after the work at the St. Catherines ring was complete (Sanger and Thomas, 2010: 66). Therefore, if these two rings are overlapping in their formative stages, then surely the differences we have witnessed in construction and development reiterate the argument that these sites follow their own trajectories.

Undoubtedly, the above conjecture regarding the formation of the rings on St. Catherines is just the beginning. Further testing of these theories is warranted, as the questions regarding the rings are still forthcoming. Analysis of the excavations and materials obtained from the rings is still in process. Hopefully, new information, in conjunction with what we have ascertained from the geophysical investigations, will bring us closer to understanding the formation process of these intriguing sites and the intentions of the people who built them.

The Interior

The shell rings on St. Catherines Island, like many other shell rings (Waring and Larson, Jr., 1968; Saunders, 2002a; Russo, 2004, 2006; Thompson, 2007), consist of a shell-free interior. This shell-free zone is not without activity, however; on the contrary, it is home to a series of intriguing circular features surrounding a central activity zone (see fig. 3.8). Similar features have been encountered at other shell rings (Russo and Heide, 2002; Saunders, 2002a; Russo, 2006; Sassaman, Blessing, and Randall, 2006; Thompson, 2007) and for the most part have been determined to either be storage or processing pits, or postholes for suspected—though not confirmed—structures (Sanger and Thomas, 2010). The exact function of the interior features at both the St. Catherines Island rings has yet to be confirmed at the time of this writing.

The depth, width, and contents of the features suggest that they could potentially be detected geophysically. Unfortunately, beginning within the first 50 cm below surface, well within the detectable zone, they have evaded our best efforts at detection with the two techniques utilized in this study. The magnetic dataset does reveal several point-specific dipolar anomalies that seem to match up with some of the circular features, but so far, these correlations have not been satisfactorily verified archaeologically. Whatever these features are, they are too similar to the surrounding matrix to be detected at this level of geophysical analysis.

Beyond the evasive circular features, the two rings share the characteristic of having strong geomagnetic signatures at the center of the interior plaza. The central feature at the St. Catherines Shell Ring is located in the precise center of the shell-free interior of the ring (see fig. 3.9, left). It is a rather large magnetic anomaly, measuring 7 × 4 m in area, and looks to be made up of several large dipolar anomalies. The one at the McQueen ring, however, consists of one crisp, dipolar anomaly that measures 3 m in diameter (see fig. 3.9B). This suggests very different behaviors in the properties of the center features, which could relate to depth of the feature, width, and certainly composition.

Excavations at the St. Catherines Shell Ring have shown that the magnetic gradient survey detected a very large feature consisting of dark, organic soil with few artifacts. Artifacts found were common for the site—Late Archaic ceramics, charred faunal remains, baked clay objects, and lithics (Semon, Mahar, and Sanger, 2008). The excavators were able to separate the major central feature into several features as excavation progressed deeper, and it seemed that the area as a whole was erratic in that features appeared to separate and converge unpredictably, making precise feature delineation difficult. Overall, it appears that the central feature at the St. Catherines ring is composed of many features; reuse of the area over time is likely the cause for the layering and intermixing of episodes. It is not a surprise that this heavily utilized area was easily detected in the magnetic survey. Unfortunately, the resistance data is of no further help regarding delineation, as the area does not seem to have detectable changes in resistance.

The McQueen ring center anomaly contrasts drastically with the features described for the St. Catherines ring. This crisp, dipolar anomaly and its surrounding area were tested in May of 2010 and excavations continued in March of 2011. As of this writing, final analysis of the materials and stratigraphy are pending. However, a few cursory observations can enlighten the current analysis without being too presumptuous. The 2010 and 2011 excavations at the center of the McQueen Shell Ring revealed quite different findings than what was uncovered at the center of the St. Catherines ring. In contrast to dark, organically rich soils, the soils at McQueen were light, mottled, nonorganic soils that faded easily into the surrounding matrix, unlike the stark contrasts seen between feature and nonfeature soil at the St. Catherines ring. The artifact content of the center anomaly feature at McQueen was also very different from St. Catherines’s. While St. Catherines’s center anomaly featured ceramics, baked clay, and lithics, the center anomaly at McQueen featured large amounts of calcined bone and little other material. It currently appears that the presence of copious amounts of calcined bone caused the strong geomagnetic signature. Some of the bone was scattered in the plow zone while the majority was concentrated in the Late Archaic horizon in the 2011 block excavation, where a pit feature was uncovered. The pit, calcined bone, and the associated mound are the leading cause of the resulting signature.

Overall, the geophysics, while not aiding in the detection of the commonly occurring circular pits, was extremely helpful in detecting other areas of interest that lie within the interior of the rings. Clearly, the interiors of the shell rings are very complex areas consisting of much more activity than periodic sweeping to keep them orderly and clean.

Conclusions

From the evidence presented in this chapter, it can be seen that a multicomponent approach involving geophysical survey and analysis, intense mapping, and excavation serves to help properly examine these intriguing and complex sites. Data provided by the multiple means included in this study not only work in tandem, but each means provides novel observations that can be used to investigate the archaeological characteristics of the aforementioned sites.

Reaching the end of this analysis, there are several areas that I believe should be expanded upon regarding the geophysics of the sites. Concerning the evasive circular pit features in the interior of the rings, we might attempt a statistical interpretation of the magnetic gradient data. Perhaps our failure to detect these features lies in our inability to properly visualize subtle differences in the gradient shade plots. Statistical methods are being used more and more in the proper identification and analysis of geophysical features (Cammarano et al., 1998; Piro, Mauriello, and Cammarano, 2000; Gaffney, Gater, and Ovenden, 2002; Kvamme, 2006a; Kvamme, 2007).

Additionally, regarding prehistoric datasets and their sometimes-vague geophysical signatures, a quantitative integration of the datasets may help to identify features of interest in a weaker dataset. A weaker dataset is defined here as one that has a low signal-to-noise ratio, which means that there is a low contrast between the archaeological feature and the surrounding matrix. This can obscure the exact position and size or shape of the feature and, in some cases, result in nondetection (Piro, Mauriello, and Cammarano, 2000: 203). This approach often results in a presence/absence or a confidence map. Once these subtle features are recognized they can then be tested and defined, thus once again providing more information with which to analyze a given archaeological site.

Further testing of detected geophysical features is also warranted. For instance, the angular resistance anomalies and circular magnetic anomalies detected at both rings possibly correlate with Late Archaic architecture. These areas should be investigated via excavation and perhaps soil chemistry testing to determine their candidacy as Late Archaic structures or living surfaces. As was pointed out earlier in this chapter, the exterior of shell rings has been largely ignored. Further investigation of these features can surely help to provide insight into the intentions and activities of the ring builders.

Outside the field, it can also be argued that further laboratory analysis should be carried out on specific soils that have been sampled from excavations at the rings. Trinkley and Ward’s work on the soil chemistry of Lighthouse Point Shell Ring in South Carolina helped to shed light on activity areas outside of the rings (Trinkley and Ward, 1978). A similar study would surely help here, especially concerning the areas where little artifactual material has been recovered, and geophysical signatures and soil color changes are all that exist to suggest prehistoric activity.

Lastly, I contend that the data and analysis presented here argue for the use of geophysical information as a principal means of archaeological investigation. The former use of geophysical data solely as a prospection method should be replaced by the method of proper data processing and graphic representation, geophysical analysis, archaeological interpretation, extrapolation, and projection offered in this chapter. The advances made in recent years involving data processing and graphic representation allow for ease of use and affordability, making the analysis of geophysical data more accessible to the general archaeological community. Processed and analyzed properly, geophysical data may stand on their own as a principal source of archaeological information. However, a thorough knowledge of the ecology, geology, history, and of course archaeology of a region is essential to proper interpretation. Overall, what has been shown here is that using more lines of evidence in site analysis can greatly improve the interpretations we are able to make as researchers.

Figure 3.1. Locational map of the Golden Sea Islands along the Georgia Bight with St. Catherines Island highlighted in red (Thomas, 2011: 26).

Figure 3.2. A selection of shell rings that have been investigated in the southeastern United States as of 2006 (Russo, 2006).

Figure 3.3. Plate showing St. Catherines Shell Ring data collection results used in the vectorization process; A, resistivity; B, topography; C, shell density contour; and D, gradiometry.

Figure 3.4. Vectorized images of the geophysical results of soil resistance and gradiometer surveys at: A, McQueen Shell Ring; B, St. Catherines Shell Ring. Green lines and polygons represent magnetic features of interest; blue lines and polygons represent soil resistance features of interest. Triangles represent shovel test pits positive for Late Archaic ceramics; testing was carried out along the exterior of the ring at a 10 m interval within 150 m from the center of each ring.

Figure 3.5. Shell midden deposit profiles from (A) the St. Catherines (N789 E801) and (B) the McQueen shell rings (N272 E200) (photographs by Anna M. Semon).

Figure 3.6. A. Magnetic gradient data from the northern section of the St. Catherines Shell Ring showing excavated units. Unit N789 E801 is shown as the northernmost white square. B. North wall profile of unit N789 E801, burnt patches of shell were identified throughout the excavation (photograph by Anna M. Semon).

Figure 3.7. Magnetic gradient map results (in nanoteslas) of (A) the St. Catherines and (B) the McQueen shell rings; note the absence of the interior magnetic “ring” feature at the McQueen Shell Ring.

Figure 3.8. The circular features that exist in the interior shell-free portion of the shell rings are still puzzling and unfortunately do not show up in the geophysical surveys. Interior features of: A, St. Catherines Shell Ring. B, McQueen Shell Ring (photographs by Anna M. Semon).

Figure 3.9. Side-by-side comparison of the central magnetic anomalies detected at (A) the St. Catherines and (B) the McQueen shell rings. The same scale has been used for each image to highlight the difference in size and characteristics between the two.

CHAPTER 4. PASTE VARIABILITY AND CLAY RESOURCE UTILIZATION AT THE FOUNTAIN OF YOUTH SITE, ST. AUGUSTINE, 8SJ31

Ann S. Cordell and Kathleen A. Deagan[6]

INTRODUCTION

The initial years of Spanish exploration, proselytizing, and occupation in La Florida provoked major changes in the demography and geographical distribution of native people throughout the southeastern U.S. coastal plain. Populations were subject to losses through introduced diseases, and movements of people and towns internally throughout the coastal region created a fluid milieu for settlement and exchange (Stojanowski, 2005a). It is widely assumed that concomitant disruption of native social order and worldview also occurred (see essays in Deagan and Thomas, 2009; McEwan, 2001).

To help understand the ways in which these social disruptions and changes in interaction patterns played out in northeast Florida, technological analysis of ceramics from the Fountain of Youth Park site (8SJ31) in St. Augustine, Florida, was carried out in 2008 by Ann Cordell of the Florida Museum of Natural History. Pottery is perhaps the most widely used archaeological index for characterizing movements of people, changes in population composition, and alteration of both conscious and unconscious daily practice (see, for examples, papers in Skibo and Feinman, 1999).

The Fountain of Youth Park site (fig. 4.1) (referred to hereafter as FOY) was the locus of sustained occupation by Timucua Indians and their predecessors for more than 2000 years. In 1565 (the initial settlement of St. Augustine), the first permanent European town in the United States was established at this site by Pedro Menéndez de Avilés of Spain. That encampment lasted just one year before Timucuan hostilities forced its relocation to a more secure position (see Deagan, 2009a). The site also contains the remains of the first Franciscan mission to the American Indians, Nombre De Dios, established in 1587, and that mission occupation continued until about 1650. Today the site is a tourist attraction dedicated to the story of Ponce de Leon’s voyages to Florida.

Excavations have been carried out at FOY intermittently since 1934, however data for this chapter were recovered between 1985 and 2008 by University of Florida field schools directed by Kathleen Deagan. Excavations have been oriented toward delineating the 1565–1566 Spanish settlement, as well as understanding changes in Timucua life after the arrival of Europeans in northeast Florida (for a summary of these field projects and their results, see Deagan, 2009a).

The geographic and tribal associations of pottery in the region at the time of European arrival are well known (Deagan and Thomas, 2009; Worth, 2009a). Three groups dominated the coastal region of the Georgia Bight between South Carolina and St. Augustine, Florida at the time of Spanish contact, each with a distinctive ceramic tradition that persisted into the colonial period (fig. 4.2). The Guale people of coastal South Carolina and northern Georgia produced sand/grit-tempered stamped wares known as “Irene” and, slightly later, “Altamaha” or “San Marcos” during the 16th century (see DePratter, 2009; Saunders, 2009; Thomas, 2009a) (fig. 4.3A; also see Deagan, 2009b: fig. 6.6). To the south of the Guale region, the Timucua-speaking Mocama Timucua produced a grog-tempered ware known as “San Pedro” (Ashley, 2009) (fig. 4.3B; also see Deagan, 2009b: fig. 6.5). The southernmost group, the “Saltwater” Timucua (as they were known to the Spanish), produced chalky, spiculate St. Johns pottery (fig. 4.3C; also see Deagan, 2009b: fig. 6.4).

Before Spanish arrival, the Saltwater Timucua who lived at FOY used St. Johns chalky ware ceramics almost exclusively (Deagan, 2009b). This changed quickly in the second half of the 16th century when pottery associated with nonlocal Mocama and Guale groups appears in significant quantities at the site (Deagan, 2009b: 156–158; Waters, 2009). This situation raises interesting questions about resilience of traditional pottery production practices in the face of social and demographic disruption. For example, to what degree did historic-period, nonlocal pottery types at FOY represent movement of people and pots into the area from elsewhere? Did Guale or Mocama potters relocate to St. Augustine, and continue producing their traditional pottery using new local resources? Did local Saltwater Timucua at FOY continue to exclusively produce their traditional St. Johns pottery, or is there evidence that they also adopted elements of Guale and Mocama Timucua pottery (as suggested by Waters, 2005 and Worth, 2009a).

Answers to these questions, although focused on the assemblage from a single early site in St. Augustine, could provide insight into the nature of intergroup Native American movements and interactions during the turbulent 16th century. The degree to which production regimens for these ceramic traditions persisted or changed is an important potential index of change or persistence in cultural practice and continuity.

The analysis of ceramics from 16th-century contexts at FOY reported in this chapter was carried out to begin evaluating these possibilities, with emphasis on detecting local versus nonlocal production. It was expected that paste characterization could yield data to indicate whether or not stylistically defined ceramic varieties (San Pedro and Altamaha/San Marcos) found at FOY were locally produced or imported. These varieties have been documented as being traditionally produced by tribal groups outside the Saltwater Timucua region (Ashley, 2009; Saunders, 2009). This question is approached through characterization of paste variability in terms of the relative number and kinds of clay resources used in manufacture of the pottery, and exploring manufacturing origin of the resource groupings. Several clay samples from the coastal region adjacent to and north of the site were analyzed for comparison.

DESCRIPTION OF THE SAMPLES

Three ceramic traditions make up most of the aboriginal pottery at FOY: local Timucuan St. Johns chalky wares (73%), Mocama Timucua San Pedro grog-tempered pottery (3%), Guale-associated Irene/Altamaha/San Marcos sand/grit-tempered tradition (5%), and remaining unassigned wares (19%) (Deagan, 2009b: 147–148). Summary descriptions of these pottery traditions are provided in table 4.1. Deagan selected a sample of 89 sherds from undisturbed 16th-century deposits at the site for analysis by Cordell. All sampled contexts are thought to have been deposited during, or shortly after, the Menéndez encampment occupation at the site (1565–1566).

The grog-tempered wares (N = 27) consist of San Pedro series sherds (Ashley and Rolland, 1997; Rolland and Ashley, 2000; Ashley, 2001, 2009), including some with Colorinda-like temper (Sears, 1957; Ashley, 2006a, 2006b). The San Pedro sample includes plain, cob-marked, and stamped surface treatments (table 4.2; fig. 4.3B). Four thin sections of San Pedro Plain from the Devil’s Walkingstick site, (9Cm177) a coastal Mocama Timucua site in South Georgia (Smith et al., 1981; Borremans, 1985; Cordell, 1993; also see Wallis and Cordell, chap. 5) were included in this study for comparison.

Sand/grit-tempered wares (N = 14) are represented by Irene/Altamaha/San Marcos series stamped sherds (fig. 4.3A) (Smith, 1948; Otto and Lewis, 1974; Saunders, 1992; DePratter, 2009). St. Johns wares (N = 48) include check stamped, plain, and several other surface treatments (fig. 4.3C). A typological listing of the sample is provided in table 4.2.

Nine clay samples were analyzed for comparison to the pottery. Six clays are from northeast Florida (fig. 4.4): one from the vicinity of FOY in St. Johns County (edge of the saltwater marsh at Fountain of Youth Park), three from Duval County, and two from Nassau County. Three clay samples are from southeast Georgia: one from Camden County, and two from Glynn County. The clay samples were collected by Neill Wallis, Vicki Rolland, and Kathleen Deagan. The FOY clay sample was thin-sectioned for this study; thin sections of the other eight clays were made available for study courtesy of Neill Wallis (Wallis, 2009, 2011).

Methods of Analysis

Three methods of analysis were carried out on the pottery sample in order to characterize paste: gross paste sorting with a binocular stereomicroscope; refiring in an electric furnace; and petrographic analysis of thin sections. These methods are the same as those used to characterize paste in the Wallis and Cordell study (this volume, chap. 5). The binocular stereomicroscope was used to identify predominant constituents and to distinguish paste differences within gross temper groupings. The microscope was equipped with an eyepiece micrometer and fiber optic illuminator. A magnification of ×30 was used because it was powerful enough to distinguish very fine particle sizes (0.0625 mm to ≤ 0.125 mm), but low enough for estimation of size and relative abundance of larger coarse and very coarse constituents (grit sizes ≥ 0.5 mm). Occasionally, higher magnifications (up to ×70) were used when necessary. All initial observations were made on sherd edges that had been freshly broken with pliers. For grog-tempered and sand/grit-tempered sherds, additional observations were made on sherd edges that had been freshly cut with a lapidary saw. The textural integrity of the pastes was remarkably well preserved in the cut edges, which also provided larger and more uniform surface areas for examination. Size of aplastics was estimated with reference to the Wentworth Scale (Rice, 1987: 38). Particle abundance was estimated with reference to a relative abundance scale.[7] Data from gross paste sorting are summarized in table 4.3.

Sherds were refired to standardize color comparisons between samples, to assess their relative iron oxide content, and for comparison to the clay samples. This method, recently referred to as oxidation analysis (Beck, 2006), follows recommendations from Shepard (1939, 1953, 1976: 105) and Rice (1987: 344) to infer gross clay composition from color class of oxidized clays. The lapidary saw was used to control the desired size of fragments for refiring (not all sherds were large enough to spare removal of pieces for refiring). Sherds were refired in an electric furnace at a temperature of 800°C for 30 minutes[8]—conditions that most likely exceeded those of the original firings. A fresh break was made after refiring to note color changes and Munsell colors were recorded for core colors of a subsample of refired sherds. Four gross refired color ranges were specified for refired sherds, corresponding to relative iron oxide contents ranging from very low to high.[9] A subsample of 30 FOY sherds was thin-sectioned for petrographic compositional and point count analyses. Sampling for thin-sectioning was proportional to gross paste variation within San Pedro and St. Johns categories, and based on sherd size for Altamaha/San Marcos and Colorinda-like categories. The petrographic analysis was conducted to evaluate compositional homogeneity and differences within and between gross paste categories. Point counts were made for quantifying relative abundance of constituents. The point-counting procedure involved using a petrographic microscope with a mechanical stage and generally followed recommendations by Stoltman (1989, 1991, 2000).[10] Four thin sections of San Pedro sherds from Devil’s Walkingstick and nine thin sections of clay samples were included in this phase of analysis. Point-count data were used to calculate a “sand size” index for each sample, following Stoltman (2000: 314).[11] Grain size analysis was also conducted on the FOY clay sample and test bars were formed and fired for comparison with sherd physical properties.[12] All analyses were carried out in the Florida Museum of Natural History Ceramic Technology Laboratory (FLMNH-CTL). SAS for Windows (SAS Institute Inc., 2008) was used for computer analysis and statistical comparisons of petrographic data. Ternary diagrams of point count data were constructed (after Graham and Midgley, 2000) for evaluation of trends.

RESULTS

Paste Constituents

Principal Constituents: The principal tempers include: quartz sand (0.0625 to < 0.5 mm), quartz and quartzite grit (≥ 0.5 mm), grog-temper, and sponge spicules. Quartz occurs in all sherds in the sample, in varying sizes and abundances. Its status as an added temper or a naturally occurring constituent, or some combination of both, is uncertain. Quartz aplastics falling into silt and very fine Wentworth particle sizes are usually considered to be naturally occurring constituents of the clay source (Rice, 1987: 411; also see Stoltman, 1989: 149–150, 1991: 109–111). Coarser particle sizes may be indicative of tempers (Rice, 1987: 411; Stoltman, 1989: 149, 1991: 109–111). Quartz was generally frequent to abundant in most sherds in the sample, but was the principal constituent in Altamaha/San Marcos samples (fig. 4.5). Polycrystalline quartz or quartzite was noted only in thin section.

Grog temper, or crushed, recycled potsherds, is an occasional to common constituent of the San Pedro sample. In the initial gross paste analysis, grog temper composition was categorized as fine/compact, sandy, or chalky/spiculate (see fig. 4.6).

Sponge spicules are the principal constituents of the St. Johns sample (fig. 4.7). Sponge spicules are variously considered to be naturally occurring constituents of the clays (e.g., Borremans and Shaak, 1986; Cordell and Koski, 2003) or as temper added to clay during paste preparation (e.g., Rolland and Bond, 2003). Sponge spicules are also rare to occasional in some San Pedro and Altamaha/San Marcos pottery, as observed petrographically. In these cases, the sponge spicules are generally more fragmented than sponge spicules in St. Johns pottery. Sponge spicules that are only occasional constituents of an otherwise sandy paste probably do not represent added temper on the basis of low frequency. Occasional sponge spicules may be natural incidental constituents of the clay source or they could have been introduced incidentally through temper sources (e.g., spiculate grog temper or from a mucky sand source) or through contamination during the manufacturing process.

Other Constituents: Mica, shell fragments and platy shell voids, ferric concretions, feldspars, mafic minerals, and other siliceous microfossils were also observed in some cases. Mica was not observed during the preliminary analysis, rather, only in thin section. Mica is considered a naturally occurring constituent of clays rather than temper. Ferric nodules or concretions are occasional constituents of most sherds, but probably also represent naturally occurring constituents of the clays. Shell temper and/or shell voids from dissolution of shell temper, are present in several Altamaha/San Marcos sherds. Feldspars (mostly microcline and plagioclase) and mafic (ferromagnesian) minerals (mostly epidote and amphibole) are occasional constituents of some sherds and were only discerned in thin section. These constituents may be natural constituents of the clay(s) or incidental to sand tempers.

In addition to sponge spicules, fragments of other siliceous microfossils, specifically diatoms and opal phytoliths, were identified in the matrix of some San Pedro and Altamaha/San Marcos pottery (and in some grog temper characterizing the former) as well as in three clay samples. Diatoms are unicellular algae with ornate cell walls made of silica. Diatoms are useful as environmental indicators and in paleoenvironmental studies (e.g., Stoermer and Smol, 1999; Round, Crawford, and Mann, 2007: 116–117) and have proven useful in applications to archaeological questions and in provenance studies of pottery and clays (e.g., Battarbee, 1988; Juggins and Cameron, 1999; Mannion, 2007). With a few exceptions, the valves and other wall components in FOY thin sections were fragmentary and problematic in terms of species identification. Fresh to brackish water, and marine diatom species were, however, identified (fig. 4.8).[13] The combination of brackish water and marine species indicates deposition under conditions at least occasionally inundated by ocean waters, reflecting coastal locales. These siliceous microfossils were particularly useful for establishing matches between pottery samples and particular clay resources in the present study.

Opal phytoliths are botanical microfossils composed of silica (Rapp and Mulholland, 1992). No attempts at phytolith species identification have been made. Diatoms, phytoliths, and fragmented sponge spicules (when only rare to occasional in occurrence) were observed only in thin section with magnifications ranging from ×250 to ×400. These microfossils are considered to be natural constituents of the clay sources, rather than incidental tempers or contaminants.

Description of Paste/Clay Resource Groupings

On the basis of petrographic data and refired paste color, a minimum of four gross potential clay resources is represented by the 16th-century aboriginal pottery at FOY (table 4.4). Each clay resource group may represent a group of similar clays, rather than a discrete clay source. For convenience they are labeled A–D (note that there is overlap in paste categories A–D in the present study and mineralogical groups A–I in Wallis and Cordell [chap. 5], but the category designations are not equivalent in most cases; Wallis and Cordell designations are included in table 4.4). Bulk composition for the resource groups is compared graphically in figure 4.9, showing that three of the four sort out into fairly distinct groupings.

Resource group A is characterized by fine or compact texture, containing about 15% sand (primarily quartz).[14] Occasional fragmented sponge spicules, phytoliths, and frequent microfossils of diatoms also occur (fig. 4.8). One case with sandy matrix texture was observed (it clusters with group B sherds in figure 4.9). Resource group A samples included sherds typologically identified as San Pedro, primarily, with one occurrence of Altamaha/San Marcos (fig. 4.10).

Resource group B is characterized by sandy texture consisting of about 30% sand and none to rare sponge spicules and absence of other siliceous microfossils. Two cases with fine/compact texture were observed (clustering with group A sherds in figure 4.9). Resource group B samples included sherds typologically identified as San Pedro (including Colorinda-like cases) and Altamaha/San Marcos (fig. 4.10).

Resource group C has fine to sandy matrix with occasional sponge spicules but no diatoms, and includes sherds typologically identified as San Pedro and Altamaha/San Marcos (fig. 4.10). A fine-textured example resembles resource group A (see fig. 4.9), but with no diatoms. Two sandy cases cluster with group B sherds in figure 4.9, while one intermediate case is an outlier (in the group D circle). In clay groups A–C, mica is a rare to occasional constituent, and relative iron oxide content is moderate to high.

Resource group D is assigned to spiculate pastes or clays, characterized by variable sand and iron oxide content. It is assumed for the present that sponge spicules were naturally abundant in the clays. Three textural subgroups, “very fine,” “fine,” and “sandy,” were sorted during the initial gross microscopic analysis on the basis of modal quartz particle size and frequency. These groupings are characterized by increasing quantities of quartz sand and decreasing quantities of sponge spicules, as shown in table 4.4 and figure 4.11 (table 4.3) (also see Cordell, 1989: 63–65; Cordell and Koski, 2003: 119–121). Examples of pennate, probably freshwater, diatoms were observed in thin section in a few cases, but only extremely rarely (table 4.4). No examples of brackish or marine species, as were observed in resource group A, were observed. Refired colors indicate that group D resources exhibit very low to low and moderate to high iron oxide content, but very fine St. Johns (SPC1) is characterized by the most cases with very low to low iron oxides. Resource group D corresponds exclusively to typologically identified St. Johns sherds, and all St. Johns samples are therefore in this resource group.

Petrographic data indicate that there is a clay source difference between group D clays and the other resource groupings, over and above differences in presence and/or quantity of sponge spicules. Resource group D differs from A–C in terms of its generally lower iron oxide content, lower occurrence of accessory minerals (mica, plagioclase, hornblende), and in both paucity and species differences of diatoms. These data support a contention that different clays were used for making St. Johns pottery from those used for San Pedro and Altamaha/San Marcos pottery.

Results by Pottery Traditions

San Pedro: Recycled sherds were added as temper to San Pedro and Colorinda-like pastes. The San Pedro sherds were sorted into fine/compact versus sandy textures during the initial gross microscopic analysis (see table 4.3). Very fine and fine are modal particle sizes for sand in San Pedro sherds with fine/compact matrix textures (table 4.3), whereas fine sand is modal for sherds with sandy matrix textures. Grog temper ranges from medium to very coarse in size, with most coarse to very coarse. Grog frequency based on point counts ranges from 3% to 11%. Most fine-textured sherds contained fine-textured grog temper (table 4.5). Sandy textured sherds contained both fine- and sandy-textured grog temper.

Petrographically, San Pedro paste exhibits clay resource groups A, B, and C (fig. 4.10). Most of the San Pedro sherds with fine/compact matrix texture correspond to resource group A, whereas most San Pedro sherds with sandy matrix texture, including those with Colorinda-like temper, correspond to resource clay B. There are, however, a few exceptions. One San Pedro sample made of resource group A has a sandy matrix, and one other made of resource group B paste has a fine-compact matrix. Two cases with sandy matrix texture correspond to resource clay C, fine to sandy matrix with occasional sponge spicules but no diatoms. Each matrix grouping, except sherds with Colorinda-like paste, contains grog temper recycled from sherds of mainly A and B compositions (table 4.5). The Colorinda-like sherds have grog temper recycled from group D St. Johns sherds (fig. 4.6C).

From consideration of matrix and grog composition in the thin-sectioned San Pedro samples from FOY (table 4.5), it is concluded that at least two clay sources were used to make the pottery and potters had access to grog temper composed of multiple categories. Generalizing back to the larger sample of San Pedro sherds from FOY is problematic, given that the criteria for defining clay resource groupings were determined petrographically. Thus it might not be safe to assume that all examples of fine/compact-textured and sandy San Pedro sherds in the FOY sample have clay group A and clay group B matrix compositions, respectively.

Consideration of matrix and grog composition in the four San Pedro samples from 9Cm177 (table 4.5) shows that at least three clay sources were used in making the pottery.

Multiple resource use is also reflected in multigenerational grog-temper particles that are present (generally rare or occasional) in most San Pedro thin sections (from both sites) (table 4.5). Most examples consist of a grog-temper particle with group A composition encompassing a smaller grog particle with group B composition. Thus the temper source consisted of sherds from a pot with group A matrix that had been tempered with crushed sherds of clay group B composition. Other combinations were also observed: group B with group A temper, group B with group B temper, group A with group A temper, and group B with group C temper (table 4.5). The latter multigenerational grog composition was observed only in the 9Cm177 sample.

Colorinda-like Samples: Five sherds in the FOY sample appear to be consistent with the type Colorinda Plain, two of which were thin-sectioned. This is grog-tempered pottery characterized by a sandy matrix and spiculate or St. Johns sherd temper (fig. 4.6C) (Sears, 1957; Ashley, 2006a). Colorinda Plain dates to the late Woodland Period, a.d. 700–900, according to Ashley (2006a). Ashley and Rolland mention that St. Johns grog is not unknown in San Pedro grog-tempered pottery (1997: 56). These samples are apparently Colorinda-like variants of 16th-century San Pedro ware, as no examples of Colorinda Plain were reported in prehistoric contexts at FOY (Deagan, 2009a).

Petrographically, Colorinda-like paste in the present sample has resource group B matrix (fig. 4.10), and temper composed of recycled group D St. Johns sherds (table 4.5). One case also had one grog-temper particle with group B composition.

Irene/Altamaha/San Marcos: Two matrix textures were observed for Altamaha/San Marcos samples during initial gross microscopic analysis: fine/compact and sandy (table 4.3). Coarse to very coarse and larger quartz or grit are prominent constituents in both textural groupings, but fine sand is modal in the sandy-textured group. Grit-size constituents were most likely added as temper to Altamaha/San Marcos pastes and have been categorized as temper in data presentation (tables 4.3 and 4.4; fig. 4.9). This conclusion is based on particle size data for the sample clays, to be presented later. Crushed shell was occasionally added in very small quantities as temper to Altamaha/San Marcos pastes. Petrographically, Altamaha/San Marcos paste includes examples of resource groups A, B, and C, but mostly B and C (fig. 4.10). Of the samples with fine/compact paste, resource groups A, B, and C are represented, whereas only group B is represented in the sandier examples. As with San Pedro, generalizing back to the other Altamaha/San Marcos sherds from FOY is problematic in the absence of a larger thin-section sample.

St. Johns Ware: St. Johns chalky, spiculate paste shows very fine, fine, and sandy variants, characterized by increasing quantities of quartz sand and decreasing quantities of sponge spicules (table 4.4; fig. 4.11). Petrographically, there is some overlap between San Pedro and Altamaha/San Marcos pastes at FOY, whereas St. Johns paste represents a distinct resource group. The St. Johns samples were assigned resource group D matrix composition. As noted earlier, St. Johns or clay group D differs from groups A–C in its abundance of sponge spicules, generally lower iron content, lower occurrence of accessory minerals, and paucity of diatoms. The differences imply a very different potting tradition from those represented by San Pedro and Altamaha/San Marcos pottery. Whether sponge spicules were naturally present in the clays or added as temper is still subject to debate.

Clay Sample Variability

Physical properties of the clay samples were compared to those of the excavated pottery samples. Comparisons were made in terms of the same properties used to characterize the clay resource groupings; i.e., composition, particle size and abundance, and refired, oxidized color. Comparisons of constituent abundance are based on point count data. Summary descriptions of clay samples are presented in table 4.6.

Most of the clay samples share physical properties (color, constituents, particle size, and frequency) with resource groupings designated for the pottery samples. Four samples (numbers 1, 7, 10, and 15) are characterized by frequent to abundant very fine to medium quartz sand, occasional diatoms, and rare sponge spicules; these are potential matches to resource group A. Four clays (numbers 4, 5, 6, and 17), are characterized by frequent to abundant very fine to medium quartz sand, none to rare sponge spicules and phytoliths, and no diatoms; these are potential matches to resource groups B. None of the samples is considered a match to group C. One clay sample (number 3) is characterized by common sponge spicules and frequent to common quartz sand, and is a potential match to sandier examples (SPC3–sandy St. Johns) of resource group D. However, this clay sample, from the Grant Mound (8Du14), is most likely a stockpiled mass of potting clay, rather than a natural clay deposit (Rolland and Bond, 2003; Wallis, 2009, 2011). Highly spiculate clays are otherwise thus far unknown in the study region (see Rolland and Bond, 2003).

Point-count data and variation in relative abundance of sand constituents within many of the sample clay thin sections indicate that there may be extreme variation within clay deposits, ranging from sandy to very fine and compact. Thus physical properties of the clays can account for much of the matrix variability (excluding tempers) observed in San Pedro and Altamaha/San Marcos pottery, graphically illustrated in figure 4.12. Finer/compact and sandy pastes could have been achieved without addition of sand tempering and perhaps without removal of excess aplastics. Figure 4.12 shows that two clay samples, one of group A (clay 1) and one of group B (clay 5), are unlikely matches in terms of excessive sand (also see table 4.6). The presence of coarse and very coarse quartz grit in the Altamaha/San Marcos samples is most likely attributable to tempering, as point-count data for the sample clays show only occasional presence of grit sizes in some samples (table 4.6).

With the exception of the FOY sample clay, clays with diatoms matching resource group A seem to be coincident with the St. Marys Meander Plain physiographic region (White, 1970; also see Wallis and Cordell, this vol., chap. 5). The recognizable diatom genera in the clay samples overlap, although there may be geographic variation in predominant species. The clay sample from the immediate vicinity of FOY was sandier (table 4.6; figs. 4.4, 4.12) than samples from Nassau and more northern counties (60–120 km north of FOY). Experiments show that it would not have yielded serviceable pots.7 This sample is in fact one of the samples excluded above as a likely source of group A pottery. But this does not preclude local occurrence of more suitable clays of group A composition or processing of sandy clays to remove excessive aplastics. Many more clay samples from the coastal strand and FOY vicinity will need to be investigated to map the geographic distribution of clays with diatoms and to corroborate any significance in distribution of particular genera.

Clays matching resource group B have a broad geographic distribution in the sample region based on extrapolating from the geographic distribution of the given clay samples. Group B clays occur both north and south of most of the former samples. The sampled clays are located at least 50 km from the FOY site.

In another study of pottery provenance involving Woodland pottery from northeast Florida and southeast Georgia (Wallis et al., 2010, Wallis, 2011, Wallis and Cordell, this volume, chap. 5), pastes comparable to those observed in the present study were distinguished. Mineralogical Group A, which corresponds to resource group B in the present study, was interpreted as local to the lower St. Johns region. Mineralogical Group C, which corresponds to resource group C in the present study, was interpreted as local to the coastal southeast Georgia/lower Altamaha River area. Interpretations of manufacturing origins were based on trace elemental and petrographic data. This may explain the apparent absence of clays resembling resource group C in the sample. These data may support the possibility of relatively local (to FOY) clay sources comparable to resource group B, whereas group C may be nonlocal. None of the Woodland pottery samples were made of clays matching resource group A.

Manufacturing Origins of FOY Pottery

The overlap in compositions of San Pedro and Altamaha/San Marcos from FOY, and between samples from FOY and 9Cm177, indicate that some of the pottery must have common manufacturing origins, which differs from the presumed local St. Johns wares. We hoped to determine if manufacturing origins for San Pedro and Altamaha/San Marcos types were local or nonlocal to FOY by considering data from the clay analyses.

Comparisons between pottery and clays shows that variability in clays occurring in the northeast Florida–southeast Georgia area can account for clay resource/matrix variability observed in San Pedro and Altamaha/San Marcos pottery. Although clays with diatoms, similar to resource group A, occur both locally and nonlocally to FOY, the FOY sample can be eliminated as a likely source of group A pottery on the basis of other criteria (excessive sand). It is thus likely that San Pedro (primarily) and Altamaha/San Marcos pottery (one case) with group A paste were made in northeast Florida/southeast Georgia and brought to FOY as pots by Mocama and Guale visitors or their intermediaries, respectively (table 4.7). One San Pedro sherd with group A paste is in fact from 9Cm177 in Georgia, which is located within the Mocama Province to the north.

Clays similar to resource group B have broader geographic distributions in the sample region. Thus, multiple manufacturing origins may have been possible for San Pedro and Altamaha/San Marcos pottery made of this paste. Clay group B includes most thin-sectioned Altamaha/San Marcos and most sandy-matrix San Pedro sherds, including the Colorinda-like samples (table 4.7). One San Pedro sherd with group B paste is from the Mocama site 9Cm177. Hypothetical clay C occurs in two Altamaha/San Marcos samples from FOY and two of four San Pedro Plain sherds from 9Cm177.

If the 9Cm177 samples represent wares local to the Mocama region, then they may serve as proxies for nonlocal manufacture of at least some of the FOY samples, especially those of groups B and C compositions. Some group B sherds, especially the Colorinda-like examples, might represent local wares on the basis of St. Johns/group D grog temper. It is reasonable to propose that this pottery was made where St. Johns pottery was actively being made and used. This was the case in the vicinity of FOY, the region of the Saltwater Timucua (Deagan, 2009a; Worth, 2009a), whereas the Mocama and Guale regions to the north were characterized by San Pedro and Altamaha/San Marcos pottery traditions, respectively (Ashley, 2009;Worth, 2009a).

Petrographic data show that sponge spicules are rare or occasional constituents of some clay samples, but the quantities are clearly insufficient to account for variability in St. Johns pottery with clay group D composition. That St. Johns pottery at FOY was locally made is supported by its sheer abundance and prominence at the site. Highly spiculate clays are thus far unknown in the St. Johns County area, however, as alluded to previously, variability in local clay resources is still poorly documented.

SUMMARY AND FUTURE DIRECTIONS

One of the acknowledged strengths of historical archaeology is the capacity to articulate textual evidence with other forms of physical evidence. In this study we have articulated documentary sources (identification of cultural/ethnic groups and information about Spanish contact and settlement) with archaeologically excavated context information, and paste characterization of clay and sherd samples. Our analysis was carried out in an effort to question the nature of resilience in traditional pottery production practices in the face of social and demographic changes provoked by European contact, using samples from the Fountain of Youth Park site in St. Augustine (the site of both the initial Spanish settlement of 1565, and of the first Florida Franciscan mission, Nombre de Dios, in 1587).

Of principal interest was the question of whether the historic-period, nonlocal pottery types present at FOY represented movement of pots into the area from elsewhere, or reflected relocation of Guale or Mocama potters to St. Augustine, continuing their traditional pottery production practices using new local resources.

Pottery production traditions are widely used by archaeologists as indices of social identity and cultural practice in both pre-Columbian and post-Columbian eras. During the European-American contact period, the tracking of local pottery traditions can provide insights into movements of people, social disruption, and changes in expressions of identity. As such, it offers a useful approach to understanding contact-induced changes from an indigenous Native American perspective.

Although this study is focused on the assemblage from a single early site in St. Augustine, with only tentative conclusions, it has provided important information about the probable manufacturing origins of aboriginal pottery in use at St. Augustine shortly after Spanish arrival. This information will help clarify the nature of multicultural indigenous interaction in the southeastern Atlantic coastal region at that time.

Four clay resource groupings were defined for the 16th-century Native American pottery at FOY. In terms of these clay resources, there is some overlap between San Pedro and Altamaha/San Marcos pottery at FOY, while St. Johns chalky paste represents a distinct resource group. Variability in clays from the northeast Florida/southeast Georgia area can account for the matrix variability observed in much of the San Pedro and Altamaha/San Marcos pottery pastes. With respect to our goal of exploring manufacturing origins of FOY pottery, our effort has yielded mixed results. St. Johns wares are assumed to be local on the basis of sheer abundance at the site. Clay resource group A, occurring primarily in San Pedro pottery, is tentatively considered nonlocal to FOY on the basis of the present analysis. San Pedro and Altamaha/San Marcos pottery made of group C paste also appear to represent nonlocal wares. Whether the pottery with group B paste represents nonlocal wares brought to FOY, or local wares made by Mocama and Guale potters living at FOY, or some combination of nonlocal and local wares cannot be determined with certainty at this time, owing to our limited understanding of clay resource variability in the Saltwater Timucua region. We suspect the answer may be a combination of local and nonlocal production. It should be possible to make these determinations with a more thorough investigation of local clays.

Either Mocama and Guale people, or their pottery, were present at the Saltwater Timucua FOY site early in the second half of the 16th century. Some of the pottery was most likely made elsewhere and brought to FOY. At this early contact period, it is still uncertain whether Guale or Mocama potters relocated to St. Augustine, and continued producing their traditional pottery using new local resources. The abundance of St. Johns pottery during this time indicates continued manufacture of traditional St. Johns pottery by the local Saltwater Timucua at FOY.

Although data presented here are compelling, samples sizes for San Pedro and Altamaha/San Marcos are extremely small. Many more samples will need to be investigated in order to ascertain how this variability extends over the broader northeast Florida/southeast Georgia landscape—and to find out if there are perceptible differences through time during the historic period. This petrographic analysis has provided baseline comparative data for addressing such questions. Fragmented diatoms and sponge spicules were unexpected constituents of San Pedro and Altamaha/San Marcos pottery at FOY. Although these microfossils were not visible in the pottery with standard microscopy, they constituted important elements for assessing the probable origins and movements of pottery at FOY. Clearly, petrographic methods were necessary to resolve questions of clay resource utilization and manufacturing origins in the present study and petrographic methods will be essential in further research on these questions.[15]

Figure 4.1. Fountain of Youth location (adapted from Deagan, 2009b: fig. 6.1).

Figure 4.2. Sixteenth-century distribution of ethnic groups (adapted from Saunders, 2009: fig. 3.1), showing location of Fountain of Youth and 9Cm177.

Figure 4.3. Pottery types in the FOY sample: A, San Marcos Stamped (left to right: FOY samples 31, 38, 39, 41); B, San Pedro Cob Marked (left to right: FOY samples 12, 1, 8); C, St. Johns Check Stamped (FOY samples 88 and 75).

Figure 4.4. Location of clay samples (white triangles and gray squares; gray squares denote clays with diatoms).

Figure 4.5. Photomicrographs of a San Marcos thin section (FOY 41) showing coarse quartz temper. A, plain polarized light (ppl); B, cross polars (xp) (×40; width of images ~ 2.25 mm).

Figure 4.6. Photomicrographs of San Pedro thin sections (ppl, ×40; width of images ~ 2.25 mm): A, relatively fine/compact matrix and grog temper (FOY2); B, relatively sandy matrix and grog temper (FOY 14); C, Colorinda-like paste (sandy matrix and St. Johns temper showing sponge spicules in circular cross section, perpendicular to their elongation [FOY 15]).

Figure 4.7. Photomicrograph of a St. Johns paste thin section (FOY 70, very fine St. Johns), showing preferred orientation of sponge spicules in longitudinal section (ppl, ×100; width of image ~1 mm).

Figure 4.8. Photomicrographs of fossil diatoms in San Pedro pottery and clay samples: brackish water species: A, Tryblionella granulata (clay sample 10; ppl, ×400; width of image ~ 0.15 mm). B, Terpsinoe americana (clay sample 7; ppl, ×250; width of image ~ 0.16 mm); marine/coastal genera: C, Diploneis (pottery sample FOY2; ppl, ×400; width of image ~ 0.15 mm) and D, Triceratium favus (clay sample 7; ppl, ×250; width of image ~0.20 mm).

Figure 4.9. Ternary diagram of bulk composition of FOY pottery resource groups.

Figure 4.10. Bar chart of resource grouping variability by pottery series (see table 4.4).

Figure 4.11. Ternary diagram showing St. Johns textural groupings (clay sample 3 is included).

Figure 4.12. Ternary diagram of matrix composition of resource groups A–C, pottery and clays.

TABLE 4.1. Summary Description of Pottery Traditions

Pottery series/ tradition

Temper composition

Matrix

Reference

Surface treatment

Time period

San Pedro Series

crushed grog (pre-fired clay)

fine to coarse sand paste

Ashley and Rolland, 1997

plain, check-stamped, cob-marked, textile-impressed, cord-marked, complicated-stamped, various others

late 16th and 17th centuries, Mocama Timucuans

Colorinda

crushed St. Johns sherds

gritty

Sears, 1957

plain

late St. Johns Ib

crushed St. Johns and nonspiculate sherds

frequent fine to medium sand

Ashley, 2006a

plain, rarely other surface treatments

late Woodland, a.d. 700–900

unnamed sherd-tempered series

small to large chunky crushed potsherds

sandy

Goggin, 1952: 57, 112; also see Ashley and Rolland, 1997: 51–52

plain, cob marked, fabric impressed, simple, complicated, and check stamped

St. Johns II and later

sherd tempered

numerous, sizeable ground sherds (some Colorinda?)

not described

Bullen and Griffin,1952

plain, cob marked, net/textile impressed, cord marked, check stamped, misc. stamped

some prehistoric, some historic period

clay tempered series

crushed pottery or clay temper (some Colorinda Plain)

not described

Hemmings and Deagan, 1973

plain, cob marked, cord marked, net/textile impressed

a.d. 700–1700

sherd or clay tempered

sherd or clay tempered

not described

Milanich, 1971

plain, cobmarked, San Marcos Stamped

mission-period Timucuan

San Marcos Series

grit, sand, sometimes limestone, shell, rarely grog

not described

Smith, 1948; Otto and Lewis, 1974; Saunders, 2000

stamped, plain, red filmed

Guale, 17th-century St. Augustine

St. Johns

abundant sponge spicules; variable quartz sand

abundant sponge spicules; variable quartz sand

Goggin, 1952; Borremans and Shaak, 1986; Rolland and Bond, 2003; Cordell and Koski, 2003

plain, check stamped predominant, many others

St. Johns period, 500 b.c.–a.d. 1700

TABLE 4.2. FOY Pottery Sample(a)

Temper tradition

Pottery series

Pottery type

Sample size

Thin section sample

grog-temper

N = 27

San Pedro

N = 22

SP Cob Marked

9

6

SP Plain

10

8(b)

SP uid stamped

3

-

Colorinda

N = 5

Colorinda Plain

5

2

sand/grit

N = 14

San Marcos

N = 14

SM uid stamped

6

4

SM Plain

3

-

SM Simple Stamped

2

-

SM net impressed

1

-

SM uid/eroded

2

2

spiculate ware

N = 48

St. Johns

N = 48

SJ Check Stamped

26

7

SJ Bold Check Stamped

5

1

SJ Plain

12

3

SJ other (various)

5

1

Total

89

34b

(a) Provenience listing on file, FLMNH.

(b) Four thin sections of San Pedro Plain from 9Cm177, Devil’s Walkingstick site included with the FOY thin section sample.

TABLE 4.3. Summary Descriptions of Gross Paste Groupings within Pottery Series

Clay resource groups

Sample size/thin section sample

Paste/matrix texture

Principal constituents

Modal sand size

Relative iron oxide content

Mean

sand size index

Bulk composition

Matrix composition

(excludes temper)

% matrix+ silt

% sand(d)

% temper(e)

% matrix

% silt + vf sand

% f-c sand

San Pedro

11/6(a)

fine/ compact

frequent grog; frequent sand

very fine, fine

moderate to high

1.08

82%

10%

(1%)

8%

85%

7%

8%

15/8(b)

sandy

frequent grog; common to abundant sand

fine

moderate to high

1.08

60.5%

33%

(1%)

6.5%

62%

8%

30%

Colorinda

5/2

sand

occas. to frequent grog; common to abundant sand

fine, very fine

moderate to high

0.96

69%

24%

(<1%)

7%

64%

11%

24%

San Marcos

9/4

fine/ compact, gritty

frequent sand/grit, occas. platy voids, shell temper

very fine to coarse

low to moderate

1.98(c)

74%

15%

11% (10%)(d)

80%

9%

11%

5/2

sandy/gritty

common to abundant sand/grit, occas. platy voids, shell temper

very fine to coarse

moderate to high

1.75

54%

31%

15% (12%)(d)

62%

9%

29%

St. Johns

23/5

very fine (SPC1)

abundant sponge spicules; occas. sand

very fine

very low to high (most very low to low)

0.66

69%

1%

30%

97%

3%

<1%

18/4

fine

(SPC2)

abundant sponge spicules; frequent. sand

very fine, fine

variable; very low to high

0.93

66%

10% (<1%)

24%

84%

9%

8%

7/3

sandy (SPC3)

common sponge spicules; common sand

very fine to medium

variable; very low to high

1.11

61%

19%

20%

72%

8%

20%

(a) Includes one thin sections from 9Cm177.

(b( Includes three thin sections from 9Cm177.

(c) One extremely low value of 1.08 excluded.

(d) Lower value in parentheses is percentage of coarse and larger grit sizes.

(e) Temper for San Pedro samples = grog; temper for San Marcos samples = coarse and larger grit and shell; temper for St. Johns = sponge spicules.

TABLE 4.4. Summary Descriptions of Paste/Resource Groupings (Petrographic Data)

Clay resource groups(a)

Sample size

Paste/ matrix texture

Bulk composition

Matrix composition (excludes temper)

Sand size index(d)

Matrix constituents

Relative iron oxide content

% matrix+ silt

% sand

% temper

% matrix

%silt+ vf sand

%f-c sand(c)

sponge spicules

diatoms

phyto-liths

mica

A

6

fine/ compact

80

12

8

83

8

9

(1/3)

1.11

1.22

2–3%

1–3%

1%

rare to occas.

moderate to high

1(b)

sandy

58

31

11

63

7

30

1.09

7

total A

77

15

9

80

7

12

(1/2)

1.10

1.20

B

2(b)

fine/ compact

86

6

8

88

8

3

(0/12)

0.86

0.98

none to rare

none

none

rare to occas.

moderate to high

9

sandy

60

33

7

62

10

28

(0.3/0.4)

1.05

1.20

11

total B

65

28

7

67

10

23

(0.3/3)

1.02

1.16

C

2

fine/ compact

69

17

15

76

10

14

(0/14)

1.14

2.08

1–3%

none

none

rare to occas.

low-moderate to high

2(b)

sandy

59

30

11

64

6

30

(0.15)

1.12

4

total C

64

24

13

70

8

22

(0.1/7)

1.13

1.60

D

5

very fine (SPC1)

69

1

30

97

3

<1

0.66

30%

none to rare

none

none

very low-high (most very low to low)

4

fine

(SPC2)

66

10

24

84

9

8

(0.5)

0.93

24%

none to rare

very low to high

3

sandy

(SPC3)

61

19

20

72

8

20

1.11

20%

none to rare

very low to high

12

total D

66

9

26

86

6

8

(<0.1)

0.88

26%

none to rare

very low to high

a Resource groups A, B, C, and D correspond to group F/G, A, C, and H in Wallis and Cordell, this volume.

b Includes one thin section from 9Cm177 in A and B and two thin sections from 9Cm177 in C.

c Lower values in parentheses, when present, are percentages of coarse and larger grit sizes; the first lower value excludes coarse and larger grit for any San Marcos cases; second lower value includes coarse and very coarse grit in San Marcos cases.

d Upper sand size index was calculated excluding coarse and larger grit sizes for any San Marcos cases.

TABLE 4.5. Grog Composition of San Pedro Sample

Site

Series

Paste texture

Sample size

Matrix composition (clay resource group)

Texture of most grog

Multi-generational grog

Grog composition(a)

8SJ31 (FOY)

San Pedro

fine/compact

5

A

mostly fine/compact

3 cases; most Aw/B; also Aw/A, Bw/B,

3(A,B); 2(B)

sandy

5

B

fine/compact and sandy

3 cases; variable Aw/A, Aw/B, Bw/A, Bw/B,

3(A,B);

1(A,B,C); 1(B)

Colorinda

sandy

2

B

most grog spiculate

-

D(b)

9Cm177

San Pedro

fine/compact

1

B

fine/compact and sandy

Bw/B

B

sandy

1

A

fine/compact and sandy

Bw/B, Bw/C

A,B,C

2

C

fine/compact and sandy

variable Aw/B, Bw/C

A,B

a Letters listed below refer to clay resource group compositions of grog particles.

b One case with one occurrence of group B composition.

TABLE 4.6. Summary Descriptions of Clay Samples

Clay sample

County/site

Paste/ matrix texture

Modal sand size

Sand size index

% matrix

%silt+ vf sand

%f-c sand(d)

Sponge spicules

Diatoms

Phyto-liths

Mica

Relative iron oxide content

Clay resource group

1

St. Johns Co. FL (FOY)

very sandy

fine

1.19

46

24

30

(2)

occas.

3%

rare

rare

high

A

3

Duval Co. FL

Grant Mound

SPC3

(sandy St. Johns)

very fine, fine

0.86

53

64(a)

13

16(a)

16

20(a)

18%

none

none

rare

moderate

D

4

Duval Co. FL

Oxeye Island

fine/ compact to sandy

very fine, fine

1.08

83

6

11

(1)

none

none

none

rare

high

B

5

Duval Co. FL Grand Shell Ring

very sandy

very fine to medium

1.11

34

18

49

(1)

rare

none

rare

none

moderate

B

6

Nassau Co. FL Amelia Island

fine/ compact to sandy

very fine, fine

0.87

81

8

11

none

none

rare

rare to occas.

high

B

7

Nassau Co. FL Little Talbot Island

fine/ compact to sandy

fine

0.97

79

5

16

(<1)

rare

1-3%

none

rare to occas.

high

A

10

Camden Co. GA Cabin Bluff Shell Ring

very sandy

very fine-medium

1.18

55

11

34

(2)

occas.

1-3%

rare

rare

moderate

A

15

Glynn Co. GA Jekyll Island

fine/ compact

very fine-medium

1.16

83

7

10

rare

1%

2%

rare to occas.

high

A

17

Glynn Co. GA Clay-hole Island

fine/compact to sandy

very fine, fine

1.13

71

13

16

(2)

rare

none

rare

rare

moderate

B

means for A clays(b)

1.10

72

8

20

(1)

means for B clays(c)

1.03

78

9

13

(1)

a Lower percentage was calculated with counts of sponge spicules excluded from the total for clay #3.

b Values for clay #1 were excluded as being excessively sandy.

c Values for clay #5 were excluded as being excessively sandy.

d Lower value in parentheses, if present, is percentage of coarse and larger grit sizes; no coarse sand in clay 3.

TABLE 4.7. Manufacturing Origins of Resource Groups

Resource groups

Matching clays

Local to

FOY

Nonlocal to FOY

Comments

A

1, 7, 10, 15

most likely no

yes

accounts for most fine-textured San Pedro

B

4, 5, 6, 17

maybe for

some

most likely for

some

accounts for most San Marcos and sandy-textured San Pedro (including Colorinda-like sherds)

C

–

no

yes

accounts for some San Marcos and San Pedro

D

3

local

–

local based on criterion of relative abundance; matching clay sources not yet discovered

CHAPTER 5. PETROGRAPHIC ANALYSIS OF POTTERY AND CLAY SAMPLES FROM THE GEORGIA BIGHT: EVIDENCE OF REGIONAL SOCIAL INTERACTIONS

Neill J. Wallis and Ann S. Cordell[16]

INTRODUCTION

For several decades, archaeologists have identified evidence of social interaction in Swift Creek Complicated Stamped pottery that is distributed widely across Georgia, northern Florida, and eastern Alabama and dates to approximately a.d. 200–800. The pioneering work of Frankie Snow (1975, 1977, 1988; Snow and Stephenson, 1998) and Betty Broyles (1968) has demonstrated the occurrence of complicated stamped vessels, sometimes hundreds of kilometers apart, that were impressed with the same carved wooden paddle. These connections, called paddle matches, indicate that either vessels, or the wooden paddles used to register the designs, were carried between sites. While these data clearly show some sort of social connection across a variety of distances, paddle matches are merely a glimpse of the past social interactions that might be more fully understood through provenance studies of archaeological pottery and its constituent materials.

Using Swift Creek paddle matches as a point of departure, we explore the mineralogy of pottery and clays across the coastal sector of southeast Georgia and northeast Florida to establish patterns in the manufacture and distribution of vessels and infer corresponding modes of social interaction. We present data from petrographic analysis of 69 pottery samples from Swift Creek sites (Wallis, 2011), 24 samples from a previous study of Deptford and St. Marys pottery (Cordell, 1993), and 10 clay samples from across the region. These data are used to construct mineralogical profiles for clay resource groupings that correspond with provenance. Clay resource groups defined by mineralogy are then compared to the results of Instrumental Neutron Activation Analysis (INAA) of the Swift Creek pottery and clay samples (Wallis et al., 2010). Finally, through the identification of nonlocal vessels, we offer a model of Swift Creek interaction and discuss future research directions.

SWIFT CREEK ON THE ATLANTIC COAST

Swift Creek Complicated Stamped pottery on the Atlantic coast is distributed primarily at sites just north of the mouth of the Altamaha River to just south of the mouth of the St. Johns River (Ashley and Wallis, 2006; Ashley, Stephenson, and Snow, 2007) (fig. 5.1). This area occupies a central portion of the Georgia Bight, consisting of a landscape of barrier islands, estuaries, tidal creeks, salt marshes, and tidally influenced rivers. The distribution of Swift Creek Complicated Stamped pottery is roughly correlated with the southern extent of the Sea Islands, distinctive composite islands of Pleistocene and Holocene age, and their associated estuarine environments that are often 6 km wide and much wider along the courses of rivers (Reitz et al., 2008; Turck and Alexander, this volume, chap. 7). Just south of the St. Johns River, barrier islands become longer, inlets are unstable, and tidal influence is much more limited, leading to lagoons that in many cases were essentially fresh water before modern dredging (Davis, 1997: 159). Clearly preferred by Swift Creek populations were the extensive estuarine environments associated with the Sea Islands that support large populations of fish, shellfish, and a diverse array of terrestrial and marine vertebrates (Parsons and Marrinan, this volume, chap. 2). These animals were targeted by Woodland Period populations year-round (Reitz, 1988; Reitz and Quitmyer, 1988; Fradkin, 1998).

Swift Creek sites can be divided into three types: small artifact scatters, large shell middens, and low sand burial mounds. Using the terminology employed by Thomas (2008), the first category likely represents field camps and special-purpose stations while the second category consists of the remains of residential bases. Indeed, many of the large shell middens have a circular or semicircular configuration that presumably corresponds with the circular shape of villages (e.g., “residential bases;” Stephenson, Bense, and Snow, 2002; Ashley and Wallis, 2006; Ashley, Stephenson, and Snow, 2007). Although evidence of structures at these arcuate middens has been elusive, these sites may result from the refuse disposal patterns of multiple households arranged around a central plaza (e.g., Russo, Schwadron, and Yates, 2006). These arcuate middens are typical of Swift Creek sites across the lower southeastern United States (Stephenson, Bense, and Snow, 2002).

Burial mounds, the third site category, were often constructed over a period of several centuries in an accretional fashion with human remains, grave goods, and sand periodically added. At least 15 burial mounds of the local Swift Creek culture have been identified on the lower St. Johns River, but few have been recorded in Georgia (Ashley and Wallis, 2006; Ashley, Stephenson, and Snow, 2007). Swift Creek burial mounds in coastal Georgia are found at Evelyn (9Gn6), and possibly Cathead Creek (9Mc360), Lewis Creek (9Mc16), and Sadler’s Landing (9Cm233). While the paucity of burial mounds in coastal Georgia may be due to site destruction, sampling bias, or differing burial practices (Ashley, Stephenson, and Snow, 2007: 22; Wallis, 2011), there are other important differences in the distribution of mounds along the coast. Along the lower St. Johns River, burial mounds are spatially segregated from contemporaneous residential bases, typically at a distance of least several hundred meters (Wallis, 2008). In contrast, the burial mound at Evelyn and probable mounds at other sites in Georgia are adjacent to extensive midden deposits. Thus, settlement patterns and mortuary traditions were apparently different along the lower St. Johns and the Georgia coast.

Pottery assemblages also vary along the coast (fig. 5.2). Early Swift Creek Complicated Stamped pottery (ca. cal a.d. 200–500), characterized by notched or crenulated rims, is found primarily along the lower St. Johns River. Early Swift Creek assemblages include mostly sand-tempered plain and charcoal-tempered plain pottery, along with lesser frequencies of complicated stamped sherds that are tempered with sand and/or charcoal. Late Swift Creek Complicated Stamped pottery (ca. cal a.d. 500–800), identified by folded or simple rounded or flattened rims, is common at sites from the lower St. Johns River to just north of the mouth of the Altamaha River (Ashley and Wallis, 2006; Ashley, Stephenson, and Snow, 2007). Late Swift Creek assemblages consist overwhelmingly of sand-tempered or grit-tempered pastes, with vessels from lower St. Johns River sites typically exhibiting smaller quartz sand temper than vessels from sites north of Amelia Island, which have larger (i.e., “grit”) quartz grains (Ashley and Wallis, 2006: 9).

Late Swift Creek assemblages also vary typologically between the lower St. Johns River and areas to the north. While Swift Creek sites on the Georgia coast typically consist of sand or grit-tempered plain and complicated-stamped vessels, lower St. Johns assemblages often include Weeden Island series and St. Johns series vessels. The sum total of these differences—variation in the built landscape and pottery assemblages—is likely indicative of social or cultural distinctions between the lower St. Johns River and coastal areas of Georgia to the north.

Even in the context of these apparent differences, there are paddle matches between sites along the coast, linking mortuary mounds on the St. Johns River with villages on the Altamaha River, as well as along the coast between the two rivers (Wallis, 2011). Specifically, there are six paddle designs that link 21 sites along the coast. There are also several paddle matches between sites in south-central Georgia and the Georgia coast (Ashley, Stephenson, and Snow, 2007). Pottery was obviously implicated in social interactions of some kind—the question is: what kind of social practices do paddle matches represent? Are paddle matches evidence of patterns of migration, seasonal mobility, postmarital residence, exchange, and/or pilgrimage? These alternatives remain indecipherable without an understanding of regional variation in clay and temper resources used in the manufacture of pottery and patterns in the distribution of nonlocal vessels, including vessels that are not Swift Creek Complicated Stamped. Toward this goal, in this chapter we present data from petrographic analysis of thin sections from a broad sample of pottery and clays and subsequently compare these data to the results of INAA. We employ these data to identify nonlocal vessels and, according to their patterns of distribution, offer an interpretation of evident social interactions.

SAMPLING

Petrographic analysis was carried out on thin sections from 69 vessels from 14 Swift Creek sites and 10 unique clay samples. These pottery samples include a majority of Swift Creek Complicated Stamped vessels (both early and late types), including 12 samples that are paddle matches between sites, along with contemporaneous sand-tempered plain and Weeden Island series samples from discrete contexts, such as single-component middens and pit features (table 5.1). All samples were selected with the goals of representing the range of variation in aplastic constituents and approximating the relative frequency of each paste recipe within the total assemblage. Clay samples were taken from Pleistocene deposits of fluvial and marine origins that are exposed along rivers and tidal streams (fig .5.3). These clay samples were not necessarily used by prehistoric potters but were considered to approximate the range of mineralogical variation on a regional level.

An additional sample of 24 petrographic thin sections from a previous study of Deptford and St. Marys (formerly Savannah) pottery from the St. Marys region was included for comparison (Cordell, 1993; also see Ashley and Rolland, 2002). The thin section sample includes nine Deptford samples from four sites in Duval County, Florida (table 5.2). Eleven thin sections of cord-marked and plain sherds had been categorized as Savannah or Savannah-related, but subsequent research by Ashley and Rolland (2002) provided data to recategorize the cord-marked samples as St. Marys (Ashley and Rolland, 2002: 29–34) and Ocmulgee III (2002: 29). The plain samples were recategorized as historic period San Pedro (Ashley and Rolland, 2002: 29; also see Ashley, 2001). These samples are from five sites in Duval and Nassau counties, Florida, and Camden County, Georgia (table 5.2). Three thin sections of Savannah Cord Marked from Chatham County, Georgia, and one of Prairie Cord Marked from Alachua County, Florida had also been included in Cordell’s (1993: 34–36) study. With a time frame of approximately cal 800 b.c. to as late as a.d. 500, the Deptford samples likely predate and perhaps temporally overlap with the Swift Creek pottery samples (Stephenson, Bense, and Snow, 2002). The remaining 15 samples postdate the Swift Creek samples.

METHODS

Petrographic analysis was conducted to evaluate compositional and textural variability in the samples and to document potential matches between pottery samples and clays. Point counts were made for quantifying relative abundance of inclusions. This procedure involved using a petrographic microscope with a mechanical stage and generally followed recommendations by Stoltman (1989, 1991, 2000). A counting interval of 1 mm × 0.5 mm to 1 × 1 mm was used, depending on the size/area of the thin section. Each point or stop of the stage was assigned to one of the following categories: clay matrix, void, silt particles, charcoal temper, grog temper, bone temper, biogenic silica (sponge spicules, phytoliths, diatoms), and very fine through very coarse quartz and other aplastics of varying compositions. For cases in which fewer than 200 points were counted (N = 8 for Swift Creek; N = 10 for Deptford/St. Marys), the thin sections were rotated 180° on the mechanical stage and counted a second time (after Stoltman, 2000: 306). Most of the point counts were made using the ×10 objective, but the ×25 objective (with plane-polarized light) was used to search for occurrence of siliceous microfossils such as sponge spicules, phytoliths, and diatoms. Size of aplastics was estimated with an eyepiece micrometer with reference to the Wentworth Scale (Rice, 1987: 38). A comparison chart of percent particle abundance (Rice, 1987: 349 [fig. 12.2]) was also used for estimating relative abundance of constituents occurring in low frequency.

RESULTS

Swift Creek

Among the Swift Creek assemblages, five predominant temper categories were observed: charcoal temper, quartz sand, quartz grit (particle size > 0.5 mm; includes some quartzite), quartz sand and grit, and grog temper (table 5.3). Bone temper was observed in some samples, but was never the predominant constituent. Other constituents included mica, feldspars, granitic rock fragments (rarely), iron concretions or nodules, birefringent grains, and siliceous microfossils (sponge spicules, phytoliths, and diatoms). Most of these other constituents, especially mica, ferric concentrations, and siliceous microfossils, are probably naturally occurring in the potting clays. Sponge spicules are potential tempering materials but are fragmentary in the samples and are only detectable in thin section with magnifications ranging from ×250 to ×400. They are therefore presumed to be natural constituents of the clay resources used for vessel manufacture. Feldspars and other birefringent minerals may be naturally present or introduced along with sand temper. Differences in fine through very coarse quartz particle sizes and other constituents are attributed to tempering practices, although some fine sand may be naturally present in some cases based on variability in some of the clay samples.

Six petrographic paste groups among pottery samples were defined according to the relative abundance of aplastic constituents considered natural inclusions in the exploited clays (table 5.4). Mica, sponge spicules, phytoliths, diatoms, silt grains, and very fine sand were deemed most significant for defining the clay resource groups. Each defined group represents a resource group made up of one or more clay resources that are similar in terms of these six constituents and may crosscut temper groupings. Using these same criteria, some of the clays were assigned to one or more of the six pottery paste categories, while others formed their own categories. For convenience, the mineralogical resource groups are designated A–I (note that, although there is overlap in mineralogical groups A–I in the present study and resource groups A–D in Cordell and Deagan [this volume, chap. 4], the category designations are not equivalent in most cases).

The clay resource groupings among pottery and clay samples can be summarized as follows. Group A comprises the most samples (N = 31) and is characterized by rare to occasional mica, absent or rare sponge spicules, and absent or rare phytoliths. On the basis of the absence or rarity of phytoliths and sponge spicules, four clays are also assigned to group A. However, the potential in each clay for variability in some constituents makes other group designations possible, as well. Group A in the present study corresponds to resource group B in Cordell and Deagan (this volume, chap. 4). Group B (N = 16) has similar constituents as group A, but is differentiated by the occasional to frequent occurrence of phytoliths. Group C (N = 4) contains variable frequencies of phytoliths and differs mainly from groups A and B in the occasional to frequent occurrence of sponge spicules. Group C in the present study corresponds to resource group C in Cordell and Deagan (this volume, chap. 4). Group D (N = 13) is defined primarily by occasional to frequent mica. Group E (N = 4) is characterized by high frequencies of mica like group D, but with occasional to frequent sponge spicules. Group F contains a single sample and is similar to group D but with occasional diatoms. Group F/G clays
(N = 3) are a potential match for the group F sherd because of matching species of diatoms. However, these clays differ from group F in having only rare sponge spicules and rare to occasional mica. Group F in the present study corresponds to resource group A in Cordell and Deagan (this volume, chap. 4). The single clay that constitutes group H is a stockpiled prepared clay from an archaeological context at the Grant site (8Du14). It contains sponge spicules as the predominant aplastic inclusion and does not match any of the pottery samples in this study. Group H corresponds to sandier examples of group D in Cordell and Deagan (this volume, chap. 4). Finally, group I clays (N = 2) are defined by very high mica content, occasional to frequent sponge spicules, and rare diatoms. Groups B, D, E, and I have no counterparts in Cordell and Deagan (this volume, chap. 4).

The five gross temper groups defined in the analysis are not isomorphic with the six clay resource groups among pottery samples (table 5.3; fig. 5.4). For example, group A and B specimens are found in each of the five temper categories. In contrast, the smaller groups (C, D, and E) demonstrate some important correlations. Group C samples (N = 4) are composed entirely of grit-tempered sherds. Group D (N = 13) consists primarily of sand-tempered sherds but also some charcoal-tempered samples. Group E (N = 4) samples are made up of grit-tempered or grit-and-sand–tempered sherds. These correlations reveal an intersection between mineralogically distinct clays and geographically circumscribed tempering traditions. To review, grit temper predominates in Swift Creek assemblages along the Altamaha River and as far south as Amelia Island while fine sand temper (often with charcoal before a.d. 500) dominates lower St. Johns River assemblages (Ashley and Wallis, 2006).

The defined resource groups correspond with geographical areas that can be usefully summarized by county (table 5.5). Sample sizes are small except from Duval County, but still group A comprises higher percentages of samples from southern counties than northern ones. Likewise, group D samples are mostly from lower St. Johns sites in Duval County. The small group E is made up exclusively of samples from Brantley, Glynn, and McIntosh counties, all in Georgia. Group B and C samples are more evenly divided by county but suffer from small sample sizes in the Georgia counties. What is more, many of the Duval county specimens may be foreign imports based on INAA data (Wallis et al., 2010). In sum, using the geographic distributions of mineralogical groups, the petrographic analysis identified two resource groups presumed to be local to the lower St. Johns River area and three resource groups probably local to the Altamaha River area. The two lower St. Johns groups are group A and group D, which differ from each other mostly in terms of mica content. The three likely Altamaha groups are B, C, and E, the latter two groups sharing occasional to frequent sponge spicules. The single sherd containing diatoms and sponge spicules (group F) is tentatively assigned a geographic origin north of the lower St. Johns region.

Deptford and St. Marys

Among the Deptford and St. Marys samples, there are four gross temper categories: quartz sand, quartz grit, grog (including St. Johns grog), and sandy St. Johns (sand and sponge spicules) (table 5.6). There is an apparent relationship between gross temper and pottery series in most cases. In this sample, Ocmulgee III, Alachua Tradition, and Savannah sherds are all grit-tempered. St. Marys samples are all sand-tempered and San Pedro samples are grog-tempered. The Deptford samples show greater variation in gross temper, with grit, sand, grog, and sandy St. Johns pastes. The two grog-tempered examples are Colorinda-like, with grog composed of crushed St. Johns spiculate sherds (Sears, 1957: 25–26; also see Ashley, 2006: 91).

On the basis of petrographic data (presence and relative frequency of siliceous microfossils, mica, and silt), these additional thin sections could be assigned to petrographic paste groups defined for the Swift Creek study (table 5.6). As with the Swift Creek samples, the gross temper or paste groupings are not isomorphic with petrographic clay resource groupings in many cases (table 5.7). Petrographic paste group A includes five sherds—three Deptford, one St. Marys, and one San Pedro—encompassing sand, grit, and grog tempers. Petrographic paste B contains only Deptford samples, encompassing grit, sand, and grog (Colorinda-like only) tempers. Petrographic paste C contains Savannah, Ocmulgee III, Deptford, and Alachua Tradition samples, mostly encompassing grit pastes, and San Pedro samples, encompassing grog pastes. Pastes D and E are both represented exclusively by St. Marys samples and sand tempers. Pastes F/G are represented by one San Pedro sherd and some of the grog temper in the San Pedro sherds (Cordell and Deagan, this volume, chap. 4). Paste H/clay 58 or sandy St. Johns paste is represented by one Deptford and one St. Marys sample.

Our previous interpretations regarding lower St. Johns manufacturing origins of petrographic paste groupings A and D are corroborated by most of the St. Marys Cordmarked samples and some of the Deptford samples. Four of five group A members and two of the three group D members are from lower St. Johns sites. Group B members are from lower St. Johns sites, but may have nonlocal origins on the basis of our findings for the Swift Creek samples. Manufacturing origins outside the lower St. Johns area for group C are also supported, with most members from coastal Georgia sites. This group is broadly distributed, identified in samples as far north as Chatham County, Georgia, and as far west as Alachua County, Florida. Although nonlocal to the lower St. Johns, this wide distribution may represent similar clay resources that are widespread across the region.

On the basis of these additional data, the use of clay resource A has longevity throughout the study region ranging from Early Woodland Deptford through the historic period. The present sample indicates that clay resources C, D, and E were utilized from Middle Woodland times (ca. a.d. 200) through the time of European contact. In contrast, clay resource B does not seem to have this longevity, as it is only identified in Deptford and Swift Creek samples.

INAA Comparisons

Measuring the concentrations of 30 elements, the data derived from INAA were used to partition 313 pottery samples from 17 Swift Creek sites into two groups: group 1 (N = 129), identified as local to the St. Johns River and group 2 (N = 98), local to the lower Altamaha River (Wallis et al., 2010). The remaining 86 pottery samples were left unassigned to any chemical group defined in the analysis. Twenty-two unique clay samples were also analyzed. Of these, three tentative chemical groups were recognized but were too small to be statistically significant. These tentative groups included group 3 (N = 5), lower St. Johns River clays, group 4 (N = 2), lower Altamaha River clays, and group 5 (N = 4), upper Altamaha/lower Ocmulgee River clays.

In general, the mineralogical groups defined by petrographic analysis of 69 samples are corroborated by the INAA chemical groups (fig. 5.5). In mineralogical group A, more than twice as many samples are chemical group 1 members (local to the lower St. Johns River) compared to chemical group 2 members (local to the Altamaha River). Group B contains more than three times as many chemical group 2 members as chemical group 1 members. Group C includes only chemical group 2 or unassigned samples while group D contains only group 1 or unassigned specimens. Group E is the most variable in terms of chemical composition but also suffers from small sample size, with only four members.

Comparison of the group allocations from INAA and petrographic analysis indicates that some samples that appear to be aberrations to these trends in provenance are probably from nonlocal vessels. For example, the INAA results indicate that two of the group B specimens from Duval County are foreign imports from the Altamaha River (e.g., chemical group 2) while one from Nassau County is unassigned to either chemical group. This leaves only two (13%) of the group B specimens as likely local productions in northeastern Florida (chemical group 1), with the remainder from southeastern Georgia. Similarly, both Duval County specimens in petrographic group C are likely imports based on chemical data, one a chemical group 2 member (Altamaha-made) and the other unassigned to any chemical group. This leaves only specimens from southeastern Georgia sites as local productions in group C.

The data from petrographic analysis of limited clay samples help clarify some of the other discrepancies between mineralogical group members, chemical group members, and their geographic distribution. Group A clays come from sites throughout the study region, from Glynn, Nassau, and Duval counties. Therefore, group A clay resources, and by extension group A pottery, are unlikely to be restricted exclusively to the lower St. Johns River. In other words, the wide distribution of group A clays sets up an expectation for heterogeneous provenance among group A pottery members. There are no natural mineralogical differences between group A clay resources distributed throughout the project area, but INAA was able to identify geographically significant chemical differences between them (Wallis et al., 2010).

Group F/G clays are also widely distributed, derived from Glynn, Camden, and Nassau counties, but seem to be coincident with the St. Marys Meander Plain (White, 1970; see Cordell and Deagan, this volume, chap. 4). For the purposes of this study, the spatial distribution of these group F/G clays has little bearing on the sourcing of sherds because only one sherd potentially matches this group. Group I seems to be the only clay group with a circumscribed spatial distribution, as the two clays comprising this group both come from the Ocmulgee/Altamaha river drainage. Group I clay is the only mineralogical group that contains moderate amounts of both sponge spicules and mica, firmly tying pottery group E to this drainage area. As the only natural clay group with moderate to frequent sponge spicules, group I clay may be related to group C pottery, which also contains sponge spicules as well as rare to occasional mica. Indeed, occasional to frequent naturally occurring sponge spicules occur only in these two Georgia clay samples and pottery samples in these two Georgia pottery groups. The lone member of group F also contains occasional to frequent sponge spicules but this vessel is tempered with spiculate paste grog (i.e., “Colorinda-like”) that may have introduced the spicules to the prepared paste.

To summarize, the similarity of mineral constituents in group A clays across the region causes this mineralogical group to crosscut the two chemical groups determined by INAA. The other mineralogical groups mostly conform to the two chemical groups but also parse them further into subdivisions on the basis of mineralogical differences. This relationship is evident in comparisons of the mineralogical and chemical categories assigned to vessels with matching paddle designs (table 5.8). With the exception of one unassigned sample, all vessels with paddle-matching designs 34, 36, and 38 share the same chemical group 2 but are split among two different mineralogical groups, A and B. These vessels were therefore all probably made near the Altamaha River, based on the chemical evidence, but with two or more mineralogically different clay sources. However, paddle-matching vessels belonging to the same chemical and mineralogical groups are more likely to have been made from very similar and presumably proximate clay resources. This is the case among three of the paddle matches. Vessels with design 36 from the nearby sites of Cathead Creek (9Mc360) and Lewis Creek (9Mc16) are assigned to chemical group 2 and mineralogical group B. Vessels with design 38 from Lewis Creek and Mayport Mound (8Du96), separated by more than 100 km, are members of chemical group 2 and mineralogical group A. Finally, vessels sharing design 291 from the Dent Mound (8Du68) and Greenfield #8/9 (8Du5544/5) belong to chemical group 1 and mineralogical group A. In contrast, two vessels sharing this design from the same site (8Du5544/5) have different mineralogical designations, group A and group D, distinct groups, but both local to the lower St. Johns River area. Thus, the data from INAA and petrographic analysis complement one another, each providing data for further distinctions where the other indicates homogeneity.

NONLOCAL VESSELS AND MODELS OF INTERACTION

Among the clay resource groups defined by petrographic analysis of the Swift Creek phase samples, nine specimens are identified as made from nonlocal materials (table 5.9). These include seven of 41 (17.1%) Swift Creek Complicated Stamped and two of 10 (20%) sand-tempered plain vessels. This proportion of nonlocal vessels among each type is higher than that of the much larger and presumably more representative INAA sample, in which 11 of 180 (6.1%) Swift Creek Complicated Stamped and 3 of 72 (4.1%) sand tempered plain vessels were identified as nonlocal (Wallis et al., 2010). Although the INAA results reveal a higher percentage of nonlocal samples for Swift Creek Complicated Stamped pottery, the difference is not statistically significant. Generally speaking, both types of vessels were transported between the Altamaha and St. Johns rivers.

Among petrographic samples, nonlocal vessels from sites on the lower St. Johns River (N = 6) have clay resource characteristics of the Altamaha River area. These vessels are members of clay resource groups B and C, both local to coastal Georgia, and group A, which was determined to be common in multiple areas along the coast. Two group A members were identified as nonlocal because of their chemical affinity to group 2, defined as local to the lower Altamaha River, and paddle matches linking these samples to sites on the Altamaha River.

Nonlocal vessels from sites on the lower Altamaha River (N = 3) have clay resource characteristics of the lower St. Johns River area. These vessels are members of clay resource group D, determined to be local to the lower St. Johns River. All of these specimens have chemical similarities to group 1, also local to the St. Johns River.

Notably, the temper categories represented in all nonlocal vessels are characteristic of their presumed origin of manufacturing. To review, grit temper predominates along the Altamaha River and coastal Georgia while sand temper is more common along the St. Johns River. Nonlocal vessels on lower St. Johns River sites that are presumed to have been made on the Altamaha River are all tempered with grit or grit and sand. Nonlocal vessels on Altamaha River sites that were presumably made near the lower St. Johns River are all sand-tempered. In sum, mineralogical inclusions, chemistry, and size of quartz temper among these samples clearly indicate the nonlocal area of their manufacture.

The proportion of nonlocal vessels at burial mounds is significantly higher than at residential bases. Among the petrographic samples, 5 of 15 (33.3%) vessels from mounds are identified as nonlocal compared to 4 of 54 (7.4%) vessels from residential bases. A two-proportion Z-test of these distributions is significant at the 95% confidence level (Z = 2.2; p < 0.05). In comparison, among vessels from sites on the lower St. Johns River from the larger INAA sample, 9 of 49 (18.3%) vessels were identified as nonlocal while only 2 of 98 (2.0%) vessels from residential bases were nonlocal, a difference that is also statistically significant (Z = 3.14; p < 0.01) (Wallis et al., 2010). What is more, although Swift Creek Complicated Stamped vessels made up only 28% of the total INAA samples from mounds, they comprise nearly 90% of the nonlocal vessels from mounds. The nonlocal origins of four of these vessels are corroborated by petrographic analysis. Clearly, on the lower St. Johns River, burial mounds were preferred locations for the deposition of nonlocal vessels, and the majority of those vessels were Swift Creek Complicated Stamped.

In light of their prevalence at burial mounds as opposed to residential bases, nonlocal vessels do not seem to be the de facto refuse of moving people, either from migrations or seasonal rounds. Either of these behaviors would presumably yield more nonlocal vessels at habitation sites. The few nonlocal vessels at residential bases may represent the exchange of vessels, the contents of vessels, or changes in residence of individuals in marriage. Yet the comparatively high proportion of nonlocal vessels at burial mounds on the lower St. Johns River cannot be linked directly to any of these behaviors or practices.

These vessels were intentionally placed on or within burial mounds, probably in the context of mortuary ceremony and were not often used or broken in local domestic contexts. Vessels were either brought directly to lower St. Johns River burial mounds from residential bases on the Altamaha River or carefully protected from breakage in local villages (or other locales) until their final deposition at mounds. Either way, these nonlocal vessels served as gifts in the sense that they were symbolic material linking together people in distant locations (Wallis, 2011). Artifacts that are mobilized in the context of death are quite often concerned with the (re)constitution of social relationships. Indeed, death often triggers remittances, in the form of exchange, for debts and obligations accrued between allied or competing descent groups (e.g., Battaglia, 1983, 1990; Kan, 1989; Munn, 1990; Weiner, 1992). In this context, nonlocal vessels and paddle matches are likely to have been the result of marriage alliances (e.g., Stoltman and Snow, 1998; Stephenson et al., 2002), but not because women carried their possessions during changes in residence. Instead, vessels were brought from the Altamaha River as offerings or may have been exchanged in the event of a marriage or death. Rather than mere detritus of people moving from place to place, many nonlocal vessels were used as tools of commemoration or assertion of alliances among descent groups geographically separated by more than 100 km.

Analysis of the mineralogical and chemical constituents of pottery and clays thus reveals that Swift Creek paddle matches and nonlocal pottery on the lower St. Johns River are the result of fairly formalized exchanges that were linked to mortuary practices and, presumably, marriage alliances with Altamaha River groups. With no samples from burial mounds along the Georgia coast, this interpretation is yet to be supported for areas outside the lower St. Johns River. Moreover, the sample size and distribution of pottery and clays currently prevent adequate characterization of clay resources in some areas of the coast, particularly areas between the Altamaha and St. Johns rivers.

Even with these limitations, the compelling results outlined here can be viewed as the beginning of a more comprehensive ceramic ecology of the Georgia and Florida coasts. Many more samples, especially clay samples, are needed to delineate the diversity of clay and temper resources that were available to potters in the past. As demonstrated in the circumscribed successes of the foregoing study, these data have the potential to make significant contributions to our understandings of many aspects of the aboriginal past: patterns of migration, seasonal mobility, settlement, resource exploitation, and exchange, to name a few. For Late Archaic and later populations, ceramic vessels were ubiquitous tools for cooking, storage, and transport that, in effect, bore witness to numerous aspects of life. With robust and dispersed sampling, in combination with studies of technology and function, ceramic vessels can serve as effective proxies for understanding specific patterns of population movement, interaction, and settlement.

SUMMARY AND CONCLUSIONS

This study used petrographic analysis to define clay resource groups among clay and pottery samples from the Atlantic coast of southeastern Georgia and northeastern Florida. Among the total 93 pottery samples and 10 clay samples, 12 groups were defined by the analysis, one of which was exclusively local to the lower St. Johns River, four of which were only local to the Altamaha River area, one that seemed to be ubiquitous along the coast, and the rest with inconclusive provenance. The allocation of provenance for these groups was supported by the results of INAA of the same, and additional, Swift Creek phase specimens. Nonlocal vessels were identified by mineralogical and chemical composition that was conspicuously similar to geographically distant pottery and clay samples. Among the Swift Creek phase samples, both Swift Creek Complicated Stamped and sand or grit-tempered plain vessels appear to have been transported between the lower St. Johns and Altamaha rivers. The distribution of nonlocal vessels at sites on the lower St. Johns River, however, is conspicuous. Here, nonlocal vessels were most often complicated stamped and were deposited primarily at burial mounds. These vessels are interpreted as gifts linked to marriage alliances among descent groups centered on the Altamaha and St. Johns rivers.

Understanding the nuances of mineralogical variation in clay resources within and between these two major drainages will require much more data. With a more robust sampling strategy, mineralogical variations in clay resources may aid in future examinations of other temporal periods and more proximate movements and exchanges, such as within river valleys. In the meantime, we have discovered that paddle matches between sites along the coast were most often the result of transported vessels, rather than wooden paddles, and that nonlocal vessels were mostly deposited at burial mounds. This pattern and the accompanying interpretation deserve comparison to other areas of the southeastern United States where Swift Creek Complicated Stamped pottery is distributed. The practices evident on the lower St. Johns River were not necessarily shared by other populations that made and used Swift Creek pottery. In light of the huge temporal and geographic expanse of this pottery type and concomitant archaeological variation, heterogeneity should be expected in the ways that pottery was implicated in social practice. This remains an exciting avenue for future ceramic studies on the Georgia and Florida coasts, and beyond.

Figure 5.1. Sites mentioned in the text.

Figure 5.2. Late Swift Creek pottery from 9Mc372 (A, B, C) and Early Swift Creek pottery from 8Du5543 (charcoal tempered; D, E) and 8Du43 (sand tempered; F).

Figure 5.3. Locations of clay samples. Asterisks denote samples from archaeological contexts.

Figure 5.4. Ternary plots of (A) bulk composition; and (B) sand texture/particle sizes among chemical groups defined by NAA (adapted from Graham and Midgley, 2000).

Figure 5.5. Bivariate plot of cobalt and chromium concentrations among clay resource group members. Ellipses represent 90% probability of membership in chemical groups 1 and 2 that were defined for 313 pottery samples (Wallis et al., 2010).

TABLE 5.1. Thin Section Sample from Clays and Swift Creek Phase Pottery

Sample number

Site no.

Site name

Pottery type

Gross paste

Petrographic paste

Chemical group

Paddle design

2004-01

8Du96

Mayport Mound

Late Swift Creek Comp Stamp

grit

A

2

38

2005-02

8Du96

Mayport Mound

Early Swift Creek Comp Stamp

charcoal

D

1

2005-01

8Du96

Mayport Mound

Charcoal Tempered Plain

charcoal

A

1

2005-03

8Du96

Mayport Mound

Charcoal Tempered Plain

charcoal

A

U1

2005-26

8Du96

Mayport Mound

Charcoal Tempered Plain

charcoal

A

1

2004-03

8Du96

Mayport Mound

Plain

grog (Colorinda)

F

1

2008-06

8Du68

Dent Mound

Late Swift Creek Comp Stamp

sand

A

1

291

2008-32

8Du68

Dent Mound

Late Swift Creek Comp Stamp

grit

B

2

34

2008-04

8Du68

Dent Mound

Late Swift Creek Comp Stamp

grit & sand

A

U2

36

2008-05

8Du68

Dent Mound

Late Swift Creek Comp Stamp

grit

C

2

2005-24

8Du68

Dent Mound

Late Swift Creek Comp Stamp

grit

A

UO

2005-25

8Du68

Dent Mound

Early Swift Creek Comp Stamp

charcoal

A

1

2008-01

8Du68

Dent Mound

Sand Tempered Plain

sand

D

1

2008-02

8Du68

Dent Mound

Charcoal Tempered Plain

charcoal

A

1

2008-03

8Du68

Dent Mound

Charcoal Tempered Plain

charcoal

A

1

2008-08

8Du17245

Tillie Fowler

Swift Creek Comp Stamp

sand

A

1

2008-10

8Du17245

Tillie Fowler

Sand Tempered Plain

sand

A

1

2008-11

8Du17245

Tillie Fowler

Early Swift Creek Comp Stamp

charcoal

B

1

2008-09

8Du17245

Tillie Fowler

Charcoal Tempered Plain

charcoal

D

1

2008-07

8Du17245

Tillie Fowler

Weeden Island

Red

sand

D

UO

2008-15

8Du14686

JU Temp

Swift Creek Comp Stamp

sand

A

1

2008-12

8Du14686

JU Temp

Early Swift Creek Comp Stamp

charcoal

D

1

2008-13

8Du14686

JU Temp

Sand Tempered Plain

sand

D

1

2008-14

8Du14686

JU Temp

Sand Tempered Plain

sand

A

1

2008-16

8Du5543

Greenfield 7

Swift Creek Comp Stamp

grit

C

UO

TABLE 5.1 — (Continued)

Sample number

Site no.

Site name

Pottery type

Gross paste

Petrographic paste

Chemical group

Paddle design

2008-17

8Du5543

Greenfield 7

Swift Creek Comp Stamp

grog

D

1

2008-19

8Du5543

Greenfield 7

Early Swift Creek Comp Stamp

charcoal

A

1

2005-23

8Du5543

Greenfield 7

Early Swift Creek Comp Stamp

charcoal

A

UO

2008-18

8Du5543

Greenfield 7

Early Swift Creek Comp Stamp

charcoal

B

1

2008-20

8Du5543

Greenfield 7

Sand Tempered Plain

sand

D

1

2008-21

8Du5544/5

Greenfield 8/9

Swift Creek Comp Stamp

sand

D

1

291

2008-25

8Du5544/5

Greenfield 8/9

Swift Creek Comp Stamp

sand

A

1

291

2008-22

8Du5544/5

Greenfield 8/9

Sand Tempered Plain

sand

D

1

2008-24

8Du5544/5

Greenfield 8/9

Sand Tempered Plain

sand

A

1

2008-23

8Du5544/5

Greenfield 8/9

Sand Tempered Plain

grit

B

2

2008-33

8Na32

McArthur

Swift Creek Comp Stamp

grit

A

2

2008-36

8Na32

McArthur

Swift Creek Comp Stamp

grit

A

2

2008-37

8Na32

McArthur

Swift Creek Comp Stamp

grit

B

2

2008-38

8Na32

McArthur

Swift Creek Comp Stamp

grit & sand

A

2

2008-34

8Na32

McArthur

New River Comp Stamp

grit & sand

A

U1

2005-08

8Na32

McArthur

Charcoal Tempered Plain

charcoal

A

UO

2005-09

8Na32

McArthur

Charcoal Tempered Plain

charcoal

A

1

2008-35

8Na32

McArthur

Weeden Island Incised

sand

B

UO

2008-57

9Cm25

Hallows Field

Swift Creek Comp Stamp

grit

B

2

2008-56

9Cm25

Hallows Field

Swift Creek Comp Stamp

grog

A

1

2008-45

9Gn6

Evelyn

Swift Creek Comp Stamp

grit

B

2

2008-47

9Gn6

Evelyn

Swift Creek Comp Stamp

grit

A

2

2008-46

9Gn6

Evelyn

Swift Creek Comp Stamp

grog

E

1

2008-44

9Gn6

Evelyn

Sand Tempered Plain

sand

D

1

2008-48

9Gn6

Evelyn

Sand Tempered Plain

grog

B

U2

2008-26

9Mc372

Sidon

Swift Creek Comp Stamp

grit

A

2

34

TABLE 5.1 — (Continued)

Sample number

Site no.

Site name

Pottery type

Gross paste

Petrographic paste

Chemical group

Paddle design

2008-31

9Mc372

Sidon

Swift Creek Comp Stamp

grit

B

2

2008-27

9Mc372

Sidon

Swift Creek Comp Stamp

grit & sand

B

U1

36

2008-28

9Mc372

Sidon

Swift Creek Comp Stamp

grit & sand

A

2

2008-30

9Mc372

Sidon

Swift Creek Comp Stamp

sand

D

UO

2008-29

9Mc372

Sidon

Sand Tempered Plain

grit

B

U2

2008-40

9Mc360

Cathead Creek

Swift Creek Comp Stamp

grit

B

2

38

2008-41

9Mc360

Cathead Creek

Swift Creek Comp Stamp

grit

B

2

2008-42

9Mc360

Cathead Creek

Swift Creek Comp Stamp

grit

E

2

2008-39

9Mc360

Cathead Creek

Swift Creek Comp Stamp

grit & sand

B

U2

36

2008-43

9Mc360

Cathead Creek

Swift Creek Comp Stamp

sand

D

UO

2004-18

9Mc16

Lewis Creek

Swift Creek Comp Stamp

grit

A

2

38

2008-49

9Mc16

Lewis Creek

Swift Creek Comp Stamp

grit & sand

B

2

36

2008-50

9Mc16

Lewis Creek

Swift Creek Comp Stamp

grit & sand

A

2

2008-51

9Mc16

Lewis Creek

Swift Creek Comp Stamp

grit & sand

E

U1

2008-52

 Brantley, GA

Kings Lake

Swift Creek Comp Stamp

grit

A

UO

2008-54

Brantley, GA

Kings Lake

Swift Creek Comp Stamp

grit

C

2

2008-53

Brantley, GA

Kings Lake

Swift Creek Comp Stamp

grit & sand

E

UO

2008-55

9Wy8

Paradise Park

Swift Creek Comp Stamp

grit

C

2

C03-58c

8Du14

 Grant

clay

H

3

C04-59c

8Du7479

 Oxeye Is.

clay

A

3

C05-60c

8Du1

 Grand

clay

A

3

C06-61c

 Nassau, FL

 Amelia Is.

clay

A

UO

C07-62c

 Nassau, FL

 Little Talbot Is.

clay

G

3

C10-63c

9Cm157

 Cabin Bluff

clay

G

UO

C13-64c

9Tf115

 Coffee Bluff

clay

I

5

C15-65c

Glynn, GA 

 Jekyll Is.

clay

G

UO

C17-66c

Glynn, GA 

 Clay-hole Is.

clay

A

4

C18-67c

Wayne, GA 

 Lower Sansavilla

clay

I

4

Abbreviations: UO = unassigned outlier; U1 = unassigned but likely member of Group 1; U2 = unassigned but likely member of Group 2. County is given for locations without site numbers.

TABLE 5.2. Thin Section Sample from Cordell 1993 Study(a)

Period/series

Sample no.

Site no.

Site name

Pottery type

Gross paste

Petrographic paste

Deptford

T2

8Du58

Brown Site I

Deptford Bold

Check Stamped

grit

B

T18

8Du59

Brown Site II

Deptford Bold

Check Stamped

grit

B

T19

8Du59

Brown Site II

Deptford Bold

Check Stamped

sand & grog (Colorinda)

A

T80

8Du5541

Greenfield Site 5

Deptford Bold

Check Stamped

sandy St. J

H

T81

8Du5541

Greenfield Site 5

Deptford Linear

Check Stamped

sand

A

T84

8Du5541

Greenfield Site 5

Deptford Check Stamped

sand

C

T87

8Du5541

Greenfield Site 5

Deptford Plain

sand & grog (Colorinda)

B

T92

8Du5541

Greenfield Site 5

Deptford Plain

sand

B

T106

8Du7523

Pelotes Island

Deptford Plain

grit

A

St. Marys

T120

8Du669

JEA site

St. Marys Cord Marked(b)

sand

A

T103

8Du7523

Pelotes Island

St. Marys Cord Marked(b)

sand

D

T49

8Na41

Amelia Island

St. Marys Cord Marked(b)

sand

D

T51

8Na41

Amelia Island

St. Marys Cord Marked(b)

sandy St. J

H

T48

9Cm177

Devil’s Walking Stick

St. Marys Cord Marked(b)

sand

D

T58

9Cm177

Devil’s Walking Stick

St. Marys Cord Marked(b)

sand

E

Ocmulgee III

T36

8Du58

Brown Site I

Ocmulgee III Cordmarked(b)

grit

C

Alachua Tradition

T93

8Al27

Rocky Point site

Prairie Cord Marked

grit

C

Savannah

T124

9Ch15

Indian King’s Tomb

Savannah Fine

Cord Marked

grit

C

T126

9Ch15

Indian King’s Tomb

Savannah Fine Cord Marked

grit

C

T127

9Ch15

Indian King’s Tomb

Savannah Fine Cord Marked

grit

C

San Pedro

T63

9Cm177

Devil’s Walking Stick

San Pedro Plain(c)

grog

C

T64

9Cm177

Devil’s Walking Stick

San Pedro Plain (c)

grog

F/G

T67

9Cm177

Devil’s Walking Stick

San Pedro Plain (c)

grog

A

T69

9Cm177

Devil’s Walking Stick

San Pedro Plain (c)

grog

C

(a) See Cordell (1993: 37, fig. 2) for site locations.

(b) Formerly Savannah Fine Cord Marked in Cordell (1993).

(c) Formerly Savannah Plain in Cordell (1993).

TABLE 5.3. Gross Paste Categories among Swift Creek Phase Samples

Gross paste

Sample size

Tempers

Matrix (%)

Aplastics (%)

Sand (%)

Ssi.5/1

Silt (%)

Very fine sand(a) (%)

Fine sand (%)

Medium sand (%)

Coarse sand (%)

Very coarse sand (%)

Petrographic paste

Other constituents(b)

charcoal-temper

15

9% charcoal temper

(grog present in 7 cases; bone temper in 3 cases)

60

40

26

0.96/1.10

3–5

7

17

2

<1

–

A = 67%

B = 13%

D = 20%

2% polyxQ

1% feldspars

<1% heavies

grog-temper

5

2-4% crushed sherds (bone temper in one case)

55

45

36

1.05/1.21

3–5

11

18

6

1

<1

A, B, D, E, F

2% polyxQ

2% feldspars

2% heavies

sand-temper

17

quartz sand

(grog temper rare in 3 cases; charcoal temper rare in one case)

58

42

36

0.94/1.10

3–5

12

21

2

<1

<1

A = 41%

B = 6%

D = 53%

2% polyxQ

2% feldspars

1%–2% heavies

grit and sand

10

quartz sand and grit (grog temper rare in two cases)

56

44

39

1.52/1.62

3–5

7

15

11

5

1

A = 50%

B = 30%

E = 20%

2% polyxQ

1% feldspars

1%–2% heavies

grit-temper

22

grit-sized quartz and quartzite

(charcoal present in one case)

60

40

38

1.97/2.02

3–5

4

10

12

10

2

A = 36%

B = 41%

C = 18%

E = 5%

4% polyxQ

1% feldspars

1% heavies

(a) Sand in very fine through very coarse size ranges consists primarily of quartz.

(b) These constituents are included in sand percentages.

TABLE 5.4. Summary Descriptions of Variability in Clay Resource Groups among Clays and Swift Creek Phase Samples

Petrographic paste group

Sample size

Estimated silt (%)

Very fine sand (%)

Mica

Sponge spicules

Phytoliths

Diatoms

Refired color

Temper group

Naa group

Comments

Relationship to clay samples

A

31

3–5%

7

rare to occasional

absent or rare

absent or rare

–

moderate-high iron

charcoal = 10

sand = 7

grog = 1

grit & sand = 5

grit = 8

1 (most charcoal, grog, sand) and 2 (most grit, grit & sand)

silt ranges from 3% to 3-5%, a difference of debatable significance (grit samples with slightly higher silt); differs from B in absence/rarity of phytoliths

possible affinity to clays 4, 5, 6 and 17

A-clay

4

1–5

6–11

rare to none, but might vary

none to rare

none to rare

–

moderate to high iron

clay 4, 5, 6, 17

3, 4, UO

potential for variability in silt, sand content and perhaps other constituents

most similar to paste A; possible affinity to pastes B and C if deposits vary in frequency of phytoliths and sponge spicules

B

16

3–5

5

rare to occasional in most

rare to occasional

occasional to frequent

–

low to moderate-high iron

charcoal = 2

sand = 1

grog = 1

grit & sand = 3

grit = 9

mostly 2

silt ranges from 3% to 5%, a difference of debatable significance; differs from A in terms of presence of noticeable phytoliths

possible affinity to clays 5 and 6 if deposits vary in frequency of phytoliths

TABLE 5.4 — (Continued)

Petrographic paste group

Sample size

Estimated silt (%)

Very fine sand (%)

Mica

Sponge spicules

Phytoliths

Diatoms

Refired color

Temper group

Naa group

Comments

Relationship to clay samples

C

4

3–5

2

rare to occasional in most

occasional to frequent

variable

–

low to moderate iron

grit = 4

2

heterogeneous group in terms of phytoliths; differs from A and B in presence of noticeable sponge spicules and lower frequency of very fine sand

possible affinity to clays 5 and 6 if deposits vary in frequency of sponge spicules

D

13

3–10,

variable

13

occasional to frequent

absent to rare

rare to absent

–

low to moderate-high iron

charcoal = 3

sand = 9

grog = 1

1

relatively micaceous compared to groups A-C; variable silt content

possible affinity to A clays 4, 6, 17 if deposits vary in mica frequency

E

4

3–10,

variable

7

occasional to frequent

occasional to frequent

variable

–

low to moderate-moderate to high iron

grog = 1

grit & sand = 2

grit = 1

variable

similar to group D, but with higher sponge spicule content

possible affinity with I clays 13, 18 or A clays if deposits vary in mica, spicules and phytoliths

F

1

3

21

occasional to frequent

occasional to frequent

rare to occasional

occasional

–

grog = 1

1

similar to D, but with more very fine sand and occasional diatoms

possible affinity to clay 18 in mica, spicule, and phytolith frequency, but diatom species difference precludes a match; might be more similar to F/G clays

TABLE 5.4 — (Continued)

Petrographic paste group

Sample size

Estimated silt (%)

Very fine sand (%)

Mica

Sponge spicules

Phytoliths

Diatoms

Refired color

Temper group

Naa group

Comments

Relationship to clay samples

F/G clay

3

1–3

variable

rare to occasional

rare

absent to rare

occasional to frequent

moderate to high iron

clay 7, 10, 15

3, UO

potential for variation in silt, very fine sand, mica and perhaps other constituents

possible affinity to paste F in diatom species

H clay

1

3–5

10

rare

18%

not observed

–

moderate iron

clay 3

3

spiculate clay, stockpiled

no matches with any of the pottery samples

I clay

2

variable

variable

frequent

occasional to frequent

variable

extremely rare

low to moderate

clay 13, 18

4,5

mica frequency is higher than sherd with F paste

similar to paste F, but diatom species difference precludes a match

TABLE 5.5. Clay Resource Groupings by County and INAA Group

Clay resource group

County

INAA G1

INAA G2

INAA unas

Total

A

Duval

13

3

3

18

Nassau

3

1

2

6

Camden

1

1

Brantley

1

1

Glynn

1

1

McIntosh

3

3

Total

17

8

6

31

B

Duval

2

2

4

Nassau

1

1

2

Camden

1

1

Glynn

2

2

McIntosh

5

2

7

Total

2

11

3

16

C

Duval

1

1

2

Brantley

1

1

Wayne

1

1

Total

 0

3

1

4

D

Duval

9

1

10

Glynn

1

1

McIntosh

2

2

 Total

10

3

13

E

Brantley

1

1

Glynn

1

1

McIntosh

1

1

2

Total

1

1

2

4

F

Duval

1

1

TABLE 5.6

Temporal, Gross Temper, and Petrographic Paste Categories for the Deptford/St. Marys Sample

Period/ series

Time frame

Gross paste

Sample size

Petrographic paste

Deptford

500 b.c. up to a.d. 800

(Russo, 1992: 114)

grit

3

A = 1

B = 2

sand

3

A, B, C

sandy St. Johns

1

H

sand & grog (Colorinda)

2

A, B

St. Marys

a.d. 1250–1500+

(Ashley and Rolland, 2002: 25)(a)

sand

5

A = 1

D = 3

E = 1

sandy St. Johns (b)

1

H

Ocmulgee III

a.d. 900–1250

(Ashley and Rolland 2002: 25)

grit

1

C

Alachua Tradition

a.d. 1250–1600

(Milanich and Fairbanks, 1980: 170)

grit

1

C

Savannah

a.d. 1150–1300

(DePratter, 1979)

grit

3

C = 3

San Pedro

16th and 17th centuries a.d.

(Ashley and Rolland, 1997)

grog (c)

4

A = 1

C = 2

F/G = 1

(a) At the time of the 1993 study, Russo suggested the time frame for Savannah-like fine cord marked pottery in the St. Marys region ranged from as early as a.d. 800–1500 (1992: 116).

(b) Percentage of sponge spicules in St. Marys sample is a little lower than typical sandy St. Johns. St. Marys sherd also contains phytoliths, which may not be typical of sandy St. Johns.

(c) Grog in most San Pedro samples also composed of F/G paste.

TABLE 5.7. Summary Descriptions of Variability in Clay Resource Groups in Deptford/St. Marys Sample

Petrographic paste group

Sample size

Estimated silt (%)

Mica

Sponge spicules

Phytoliths

Diatoms

Temper group

Pottery type

Relationship to clay samples

A

5

1–3

none to rare

absent or rare

absent or rare

-

sand = 2

grit = 1

grog = 1

Colorinda = 1

Deptford = 3

St. Marys = 1

San Pedro = 1

possible affinity to clays 59, 60, 61, 66

B

4

3–5

none to rare

rare to occasional

occasional to frequent

-

sand = 1

grit = 2

Colorinda = 1

Deptford

possible affinity to clays 60 and 61 if deposits vary in frequency of phytoliths

C

8

1–7, variable

none to rare

occasional to frequent

occasional to

frequent (c)

-

sand = 1

grit = 5

grog = 2

Alachua = 1

Deptford = 1

Ocmulgee III = 1

San Pedro = 2(a) Savannah = 3

possible affinity to clays 60, 61, 66 if deposits vary in frequency of sponge spicules and phytoliths

D

3

1–5,

variable

occasional to frequent

absent to rare

rare to absent

-

sand = 3

St. Marys

possible affinity to A clays 59, 61, 66 if deposits vary in mica frequency

E

1

3

occasional to frequent

occasional to frequent

variable (occasional to frequent)

-

sand = 1

St. Marys

possible affinity with I clays 64, 67, or A clays if deposits vary in mica, spicules and phytoliths

H

2

1–3

none to rare

5%–15% (estimated)

none to occasional

-

SSJ = 2

Deptford = 1

St. Marys = 1(b)

clay 58?

F/G

1

5

rare to occasional

occasional to frequent

rare to occasional

occasional to frequent

grog = 1

San Pedro = 1a

possible affinity to clays 62, 63, 65 diatom species

(a) Some grog temper composed of F/G clays.

(b) Percentage of sponge spicules in St. Marys sample is a little lower than typical sandy St. Johns. St. Marys sherd also contains phytoliths, which may not be typical of sandy St. Johns.

(c) All cases contain noticeable phytoliths. This is in contrast to the Swift Creek phase samples defined as Group C in which phytoliths were variable. In two of four Swift Creek samples phytoliths were not present or rare.

TABLE 5.8

Clay Resource Groupings and INAA Chemical Groups for Paddle Matching Vessels

Abbreviations: petid = petrographic analysis indentification; Petpaste = petrographic (mineralogical) paste category; INAA = instrumental neutron activation analysis chemical group; unas=unassigned to any chemical group defined in the analysis.

Petid

Site

Temper

Petpaste

INAA

Paddle no.

Design

2008-26

9Mc372

GRIT

A

2

34

2008-32

8Du68

GRIT

B

2

2008-04

8Du68

GSAND

A

2

36

2008-27

9Mc372

GSAND

B

unas

2008-39

9Mc360

GSAND

B

2

2008-49

9Mc16

GSAND

B

2

2004-01

9Mc16

GRIT

A

2

38

2004-18

8Du96

GRIT

A

2

2008-40

9Mc360

GRIT

B

2

2008-06

8Du68

SAND

A

1

291

2008-21

8Du5544/5

SAND

D

1

2008-25

8Du5544/5

SAND

A

1

TABLE 5.9. Samples Identified as Nonlocal by Clay Resource Grouping

Sample number

Site no.

Site name

Pottery type

Gross paste

Petro. Paste

Chemical group

Paddle design

2004-01

8Du96

Mayport Mound

Late Swift Creek Comp Stamp

grit

A

2

38

2008-04

8Du68

Dent Mound

Swift Creek Comp Stamp

grit & sand

A

U2

36

2008-05

8Du68

Dent Mound

Swift Creek Comp Stamp

grit

C

2

2008-32

8Du68

Dent Mound

Swift Creek Comp Stamp

grit

B

2

34

2008-16

8Du5543

Greenfield 7

Swift Creek Comp Stamp

grit

C

UO

2008-23

8Du5544/5

Greenfield 8/9

sand tempered plain

grit

B

2

2008-44

9Gn6

Evelyn

sand tempered plain

sand

D

1

2008-43

9Mc360

Cathead Creek

Swift Creek Comp Stamp

sand

D

UO

2008-30

9Mc372

Sidon

Swift Creek Comp Stamp

sand

D

UO

[1]We gratefully acknowledge the St. Catherines Island and Edward John Noble foundations for their long-term support of archaeological research on the island. We are particularly grateful to Buddy Sullivan, Jack Waters, and Jeff Woods for their assistance in obtaining new known-age, prebomb oyster shell samples in Liberty and McIntosh counties, Georgia. We also acknowledge the assistance of Douglas Kennett and Brendan Culleton in processing the new high-precision samples from St. Catherines Island. We also greatly appreciate the assistance of Lorann Pendleton Thomas and Diana Rosenthal in preparing this manuscript.

[2]Whereas the simple mean treats each variate as equally significant, the weighted mean assigns an importance, or “weight,” to the various observations. In the case of ΔR, the individual ΔR values are inversely weighted according to their associated error terms (expressed as weight = 1/error2). In effect, the smaller the error, the higher the weight assigned to a given value of ΔR. The various error estimates associated with the mean of ΔR likewise affect the weighting of the initial, sample-specific error estimate.

[3]Another problem is that miscommunication with the radiocarbon laboratory resulted in the 13C/12C ratio being omitted from several of the Meeting House Field 14C determinations (Thomas, 2008: chap. 13, table 13.4). Rather than attempt to estimate the results with dummy values, we have excluded these dates from consideration here.

[4] We would like to thank Dave Thomas and Victor Thompson for inviting us to participate in the sixth Caldwell Conference and to be included in this volume. We would also like to thank the staff of the American Museum of Natural History and Lorann Pendleton for their hospitality and good company during the conference. We are indebted to our reviewers: Torben Rick, Christopher Rodning, Thomas Pluckhahn, and an anonymous fourth reviewer for their thoughtful critiques and valuable insight into this manuscript. We would like to thank Betsy Reitz, who analyzed several of the samples we have used. We are also grateful to Timothy Parsons, who created the figures in this chapter. Finally, we would like to thank the Edward John Noble Foundation for the generosity that facilitates the publication and distribution of this volume.

[5]I would first like to thank David Hurst Thomas and Victor Thompson for inviting me to be a part of this volume. This chapter is based on my 2010 master’s thesis completed through Hunter College, New York, NY. This work was made possible by funding from the Edward John Noble Foundation and the St. Catherines Island Foundation and support from the American Museum of Natural History. I am forever indebted to Dr. David Hurst Thomas for the opportunity to work on this material and for the guidance he has provided over the years. I would like to thank my friends and colleagues at the American Museum for their encouragement and support throughout the various stages of this project: Lorann Pendleton Thomas, Matt Sanger, Elliot Blair, Matt “Nappy” Napolitano, Rachel Cajigas, and Christina “Cheeks” Friberg. A heartfelt thank you goes to the dedicated participants of the St. Catherines Island Archaeological Project field crew that helped to collect the data used in this study and to Royce Hayes and the St. Catherines Island staff for all their help on and off site. I am indebted to Dr. Lewis Somers for everything from survey troubleshooting to physics lessons. I would also like to thank Dr. Victor Thompson for his helpful suggestions as the final product was being formed, my advisor Dr. William Perry, and Diana Rosenthal for her masterful editing skills.

[6]The authors are grateful for the opportunity to contribute to this volume. Impetus and direction for this study were provided by Kathleen Deagan, Distinguished Research Curator Emerita, Florida Museum of Natural History (FLMNH). Florida Bureau of Historical Resources Special Category Grant # SC 161 provided funding for FOY thin-sectioning. The clay samples were made available for study by Vicki Rolland, Neill Wallis, and Kathleen Deagan and the clay thin sections were provided courtesy of Neill Wallis. We are grateful to Michael Sullivan for conducting diatom species identifications. We also thank the reviewers, Christopher Rodning, Thomas Pluckhahn, and Torben Rick whose comments significantly improved this work. Special thanks go to Diana Rosenthal and the AMNH editorial staff for guidance throughout the editorial process. The FOY pottery samples are curated in Historical Archaeology at FLMNH. FOY and 9Cm177 pottery and clay thin sections are curated at FLMNH-CTL.

[7]The relative abundance scale is as follows: abundant, common, frequent, occasional, rare, and none.

[8]The kiln temperature was initially set at 275°C and held for 10 minutes (with kiln door slightly open to allow for escape of water vapor). Then the kiln door was shut completely and the temperature was raised to 800°C. After 15 minutes, the 800°C temperature was achieved and was maintained for 30 minutes. The total firing time was approximately 77 minutes.

[9]Very low iron oxide content is represented by white to very pale brown refired colors. Low to moderate iron oxide is represented by light yellowish brown refired colors. Reddish yellow to light reddish brown refired colors represent moderate iron oxide and yellowish red to red refired colors represent high relative iron oxide contents.

[10]The counting interval ranged from 1 mm × 1 mm to 1 mm × 0.5 mm, depending on the size or area of the thin section. Each point or stop of the stage was assigned to one of the following categories: clay matrix, void (including channel voids, closed pores, and micropores [Rice 1987: 350]), silt particles, sponge spicules, grog temper, and very fine through very coarse quartz and other aplastics of varying compositions. Most of the counts were made using the ×10 objective, but the ×25 objective (with plane-polarized light) was used to confirm the occurrence of sponge spicules and other siliceous microfossils. Size of aplastics was estimated with reference to the Wentworth Scale (Rice 1987: 38). A comparison chart of estimated percent particle abundance (Rice 1987: 349 [fig. 12.2]) was also used for estimating relative abundance of silt and sponge spicules when occurring in low frequency. For cases in which fewer than 200 points were counted (N = 3), the thin sections were rotated 180° on the mechanical stage and counted a second time (after Stoltman, 2000: 306).

[11]Counts of quartz and other nonopaque minerals (e.g., quartzite, feldspars, mafic minerals) were included in calculation of sand size indices. Sponge spicules, silt, and other matrix constituents were excluded from this calculation. A second sand size index is also listed, which takes into account the size difference between very fine and fine sand inclusions. In the second index, very fine grains are given a value of 0.5 while fine grains have a value of 1.

[12]Details and results of the sample clay analysis are on file in the FLMNH-CTL.

[13]The diatom identifications were provided by diatomist Michael Sullivan.

[14]The terms “quartz sand” or just “sand” here and elsewhere in this chapter refer primarily to quartz grains, but includes grains of polycrystalline quartz, and other crystalline accessory constituents

[15]Petrographic analysis of a small sample of San Pedro and San Marcos pottery from 8Du53, San Juan del Puerto, a 17th-century Mocama mission (see Gorman, 2008a), was conducted recently by Ann Cordell. Resource groups A, B, and C are present, primarily B (Gorman, n.d.).

[16]The authors are grateful for the opportunity to contribute to this volume. Funding for this research was provided by a doctoral dissertation improvement grant from the National Science Foundation (#0744235). Pottery samples came from collections at South Georgia College, University of Georgia, University of West Georgia Waring Laboratory, Environmental Services, Inc., Florida Archeological Services, Jacksonville Museum of Science and History, and the Florida Museum of Natural History. In addition to those collected by the authors, clay samples were obtained by Vicki Rolland, Carolyn Rock, Brian Floyd, Fred Cook, and Keith Ashley. Pottery and clay thin sections are curated in the Florida Museum of Natural History Ceramic Technology Laboratory.