Exploring Oyster (Crassostrea virginica) Habitat Collection via Oxygen Isotope Geochemistry and its Implications for Ritual and Mound Construction at Crystal River and Roberts Island,Florida

Research at Crystal River and Roberts Island Shell Mound Complex, on the western coast of Florida, USA, offers a quantitative assessment of the temporality of shell deposit construction, Native subsistence practices, and mobility patterns through stable oxygen isotope data from eastern oyster (C. virginica). The δ¹⁸O_water values of oysters vary synchronously with salinity, assuming relatively constant δ¹⁸O_water/salinity gradients since the time of occupation, allowing for an examination of shifts in oyster habitat exploitation over time. Our previous (Thompson et al. 2015) study indicated that midden accumulation occurred throughout the year, while oysters from mound deposits were collected in colder months. New data indicate that in addition to differential season of collection, habitat exploitation also varied. During early occupation at the site, oysters were collected primarily from lower saline habitats, while in later phases oysters were obtained from higher salinity waters; we relate this to a lower sea level and concomitant settlement shift seaward. Additionally, oyster from later mound contexts was collected from higher saline habitats relative to those in midden contexts; Native people may have targeted specific bioherms at certain times for the year for feasting-related mound construction.     

Archaeological Site or Natural Marine Community? Excavation of a Submerged Shell Mound in Ninigret Pond,Rhode Island

ABSTRACT

Submerged shell midden sites and natural shell deposits can have similar characteristics and can be difficult to distinguish archaeologically. We excavated two test units from a large (at least 35 m×70 m) submerged shell mound in Fort Neck Cove in southern Rhode Island to assess whether it was natural or cultural in origin. This mound had been recognized as a potential archaeological feature as early as the 1970s. Excavation, radiocarbon dating, and subsequent laboratory analysis of excavated materials suggest that the mound was a natural oyster reef rather than a submerged archaeological site. No artifacts were found; there was no clear evidence for human modification of any shells; small species that would not have been targeted as food were present; and δ¹³C values of oyster shells from the mound were consistent with freshwater input into their growth environment, suggesting that they grew in an estuarine environment that did not exist prior to the inundation of the ponds. The stratigraphically oldest radiocarbon date we could obtain (430–190 cal BP, 2σ range), from 70 cm below the pond floor, placed deposition of shells at least 3,000 years after the inundation of the pond. The excavation methods that we used and the process of testing, irrespective of whether the feature is cultural, are valuable contributions to the methodological literature on submerged site archaeology and help provide insight for other researchers working to discern natural from cultural shell midden sites.     

Evaluating the Reliability of Fluoride Dating at Two Prehistoric Mound Sites in Mississippi

Abstract

Ion-selective electrode fluoride dating is used to address chronological problems at two mound sites located in Mississippi. At the Mississippian period (A.D. 900–1520) Lyon's Bluff site, 220K520, the fluoride content of deer and human bone is compared with radiocarbon dates and stratigraphic levels to evaluate the reliability of the fluoride dating method for understanding relative burial chronology. At a second site, Pocahontas Mound A (22HI500), fluoride content of deer bone is used to corroborate radiocarbon dates and to establish the proper chronology of levels associated with two distinct occupations (Archaic and Coles Creek/Plaquemine) identified in a large midden area. Fluoride analysis also is used to date a second midden area at this site. For Lyon's Bluff; fluoride dates did not correspond with accelerator mass spectrometry (AMS)-dated burials and midden strata. In contrast, fluoride dating proved very useful in determining chronological placement of midden levels and dating other areas at Pocahontas Mound A. Sample age, site location, soil, and bone preservation are considered as possible causes for the negative results at Lyon's Bluff.     

CHRONOLOGY,SITE FORMATION,AND THE WOODLAND-MISSISSIPPIAN TRANSITION AT BAYSHORE HOMES,FLORIDA

Bayshore Homes (8PI41) is a large mound and midden complex on Florida’s west-central Gulf Coast that was investigated originally by William Sears in the 1950s. From 1999 to 2009, the authors conducted survey, test excavations, and soil coring to address questions regarding site formation, chronology, and cultural affiliation. Radiocarbon dates and ceramic analysis indicate two separate occupations during the Woodland and Mississippi periods, cal. A.D. 140–565 and cal. A.D. 890–1390 (2 sigma). The earlier occupation is associated with the Manasota archaeological culture, sand-tempered plain pottery, burials in midden deposits, and interments in a sand mound accompanied by Weeden Island–related mortuary ceramics. The later occupation is associated with Weeden Island–related decorated and Pinellas Plain ceramics in midden deposits and represents the transition from terminal Weeden Island to the Englewood phase of Early Safety Harbor. A large burial mound and a platform mound are associated with this period of site use. Our results also indicate that the unusual ceramic sequence identified by Sears in the site’s large shoreline shell midden is the result of redeposition, which occurred sometime after cal. A.D. 1220. Possible explanations for the redeposition event include monumental mound construction or the elevation of the midden ridge to serve as a foundation for structures to protect them from rising sea levels or storm surges.     

PASTE CHARACTERIZATION OF WEEDEN ISLAND POTTERY FROM KOLOMOKI AND ITS IMPLICATIONS FOR SPECIALIZED PRODUCTION

Abstract

We report the results of a petrographic analysis of pottery from Kolomoki, a Middle and Late Woodland period mound and village complex in southwestern Georgia. Thin sections of 65 sherds representing several prestige and utilitarian Weeden Island pottery types, from both domestic (midden) and ceremonial (mound) contexts, were obtained. For comparison, we also analyzed samples from a few potential clay sources. We characterize the range of variability in paste/resource groupings present in the Kolomoki assemblage and use these data to address patterns of manufacture and exchange of Weeden Island pottery through comparisons to thin sections of comparable types from the McKeithen site and other Weeden Island sites in the region.     

THE CHRONOLOGY OF MONKS MOUND

Abstract

Monks Mound is the largest single Native American construction in North America. The mound sits at the center of the Cahokia site, and interpretations of its construction and use are fundamental for understanding how Mississippian peoples created mounds and landscapes. In the past, researchers speculated that Monks Mound was both one of the oldest and longest-lived monuments at Cahokia. Using a Bayesian computer model that incorporates both archaeological information and radiocarbon dates, I argue the mound is younger and was built more rapidly than previously thought. The mound likely was built in two very rapid efforts spanning fewer than twenty years. This analysis shows Cahokian society could mobilize vast quantities of labor for short periods, which may have inhibited institutionalized, transgenerational sociopolitical hierarchies.     

THE BILTMORE MOUND AND HOPEWELLIAN MOUND USE IN THE SOUTHERN APPALACHIANS

Abstract

Biltmore Mound, located on the Swannanoa River in Asheville, North Carolina, was constructed over a Connestee phase habitation, the earliest evidence dating to about A.D. 300. Mound construction began sometime between A.D. 400 and 550, with the second to last mound stage constructed about A.D. 580–600. Because of the diverse contexts and the excellent preservation of faunal remains, we are able to provide some insights into Connestee ritualism at Biltmore Mound. The Biltmore Mound was a platform used to support large public structures for ritual and ceremonial activities. It was constructed of varying colored and textured soils from a variety of source areas that arguably had symbolic importance. The mound was primarily built out (rather than up) with several mantles that may have comprised a complete ritual cycle of mound construction.     

THE 1974–75 EXCAVATIONS AT MOUND BOTTOM,A PALISADED MISSISSIPPIAN CENTER IN CHEATHAM COUNTY,TENNESSEE

Abstract

Mound Bottom (40CH8) is a large complex of 14 prehistoric mounds located in a horseshoe-shaped bend of the Harpeth River, a tributary of the Cumberland, in Cheatham County, Tennessee. It, together with another mound group 3 km to the south known as the Pack site (40CH1), received sporadic archaeological attention during the first half of the twentieth century, but it was not until 1974 that systematic work was carried out at either mound center. Over portions of that and the following year, Mound Bottom was mapped in detail and excavations were carried out to document the range in variability of mound construction and community structure. Six mounds were tested and 19 houses were partially or totally excavated. House types included both single-set-post structures and wall-trench structures. Calibrated radiocarbon dates from Mound Bottom span about a 600-year period from the eighth through the fourteenth centuries.     

CONFIRMATION OF AN ARCHAIC PERIOD MOUND IN SOUTHWEST MISSISSIPPI

Abstract

Site 22LI504 is a predominantly Archaic period site in Lincoln County, Mississippi. One of its primary elements of interest is a single conical mound from which small-diameter cores revealed evidence of advanced pedogenesis. A radiocarbon sample from one soil core produced a date suggesting that the mound was Archaic in age (Fulmer 2001); however, it was unclear whether the sample came from within the mound or an underlying midden. In the spring of 2006, we excavated a 1-x-1-m unit in the mound to investigate this question. Diagnostic lithic artifacts, an advanced state of soil horizonation, and a lack of ceramics indicate that the mound is of Archaic period construction, with as many as five construction stages and artifact-rich features. We describe the soil profiles, features, and artifacts recovered from the mound, with comparisons to excavation units in an adjacent Archaic midden to show that there is no clear evidence for the mound being a functionally specific locus. We also present radiocarbon dates that indicate the earthwork is over 5,000 years old. These results are evaluated within the broader context of Archaic mound building, focusing in particular on environmental parameters underlying bet-hedging behavior.     

Comparison of mangrove oyster shells lengths harvested in Cuba during the pre-Columbian era and the present day

Abstract

The Mangrove oyster [Crassostrea rhizophorae (Guilding, 1828)] was intensely harvested in the pre-Columbian era by an aboriginal group of hunters and gatherers known as the Ciboney who lived exclusively in Western Cuba. During a comprehensive study of mangrove oyster fishing areas it was of interest to compare the population characteristics under contemporary exploitation with those in pre-Columbian times and for that purpose two samples were used: one from a Ciboney midden in an archeological site 3 km inland from the Jaruco River mouth and another from a commercially exploited population in the ecologically similar Tacajó River. The samples were studied with a ‘shell classifier’ of original design resulting in a mean length of 51.8 ± 2.5 mm for the midden shells and 51.0 ± 3.1 mm for the contemporary sample. Both values were not statistically different for any P > 0.10 meaning that the two populations they came from had similar characteristics. It was also concluded that the Ciboney's manual harvesting exerted less negative anthropogenic pressure on the mangrove oysters’ populations than the contemporary commercial practices based on the use of metal instruments to gather the oysters along with the mangrove aerial roots they are attached to. This latter conclusion is based on the fact that oyster shells 41–80 mm long from the midden are 12% more abundant than in the modern sample, in spite of 500 years of weathering.     

Geochemical methods for inferring seasonal occupation of an estuarine shellmound: a case study from San Francisco Bay

Seasonal patterns of Native American residence and use of shell mounds of the San Francisco Bay area, California are of great interest. This work investigates seasonal occupation by means of a new method for interpretation of geochemical data from Mytilus trossulus specimens recovered from one of these structures, the Ellis Landing Shell Mound (CA-CCO-295). The approach, which is suitable for relatively small shell fragments from a variety of archaeological contexts, is used to infer the environmental conditions (temperature and salinity of ambient water) at harvest time, compared with average conditions for the period, and thus estimate the season during which the shells were harvested. This information, in turn, is employed to evaluate current models about the growth and construction of prehistoric shell mounds in San Francisco Bay. The method was applied to seven different lenses in the shell mound ranging in age from ∼240 cal yr BP to ∼3510 cal yr BP. We found that, although seasonal occupation varied over time, it generally was confined to summer through late fall, with little indication of winter gathering. Our findings suggest that California shell mounds, such as Ellis Landing, were constructed in a very different manner than some other mounded places used by contemporaneous hunter-gatherers elsewhere in North America.     

A REASSESSMENT OF THE CHRONOLOGY OF MOUND A AT TOQUA

Abstract

The Toqua site (40MR6) is one of the most thoroughly excavated Late Mississippian mound sites in East Tennessee. The site has been a focal point of research on late prehistory in southern Appalachia, but there are issues surrounding its chronological placement. The radiometric dates obtained for the site in the 1970s and the archaeomagnetic dates reported in 1999 have large standard deviations. These dates are too imprecise to be useful for a temporal placement of the site that is clear enough for current discussions of the development of Mississippian culture. A newly obtained Accelerator Mass Spectrometry (AMS) date from the large platform mound (Mound A) allows a reevaluation of the occupation sequence of the Toqua site. This date provides an anchor for a refined chronology for Mound A. In addition to the new AMS date, this refined chronology is based on complementary lines of evidence, including architectural evidence, mortuary practices, pottery traditions, and shell gorget styles.     

Constructing community at civic-ceremonial centers: pottery-making practices at Crystal River and Roberts Island

ABSTRACT

Crystal River (8CI1) and Roberts Island (8CI36, 8CI40, 8CI41) are neighboring mound complexes on Florida’s west-central Gulf Coast, with mainly sequential occupations during the Middle and Late Woodland periods, respectively. Previous work at Crystal River produced assemblages marked by a diversity of pastes and surface treatments, suggestive of distinct communities of practice. However, these excavations were unsystematic and poorly controlled, thus confounding understanding of temporal and spatial variation in practice. Recent excavations in domestic areas, combined with the analysis of older collections from mounds, support a finer-grained understanding of variation in ceramic production. Our analysis suggests that communities of practice persisted through time, although there is variation that corresponds well with changes in settlement.     

Building Monks Mound,Cahokia, Illinois,a.d. 800–1400

Abstract

Cahokia (a.d. 800–1400), located near the confluence of the Mississippi and Missouri rivers, was the largest settlement in ancient North America. Monks Mound occupies the center of Cahokia and provides both a modern and ancient focal point for the site. Past investigations of Monks Mound explored issues of mound chronology and use. Recent soil coring around the perimeter clarifies the geological context and degree of preparation necessary before the mound was built. The results suggest that the mound is not optimally positioned for stability and its location may ultimately accelerate deterioration. Moreover, evaluation of the mound features and fill indicates that maximization of the geotechnical potential of sediments was not a primary concern for the Cahokians. Although poorly engineered relative to modern standards, the suitability of the mound as a platform may have been secondary to other design choices made while building the largest single mound in ancient North America.     

THE BEAD MAKER’S MIDDEN: EVIDENCE OF LATE PREHISTORIC SHELL BEAD PRODUCTION ON OSSABAW ISLAND,GEORGIA

Abstract

In 2005, archaeological excavations were undertaken in a single shell midden at a late prehistoric Irene phase (circa A.D. 1380) site on Ossabaw Island, Georgia. The excavations were designed specifically to collect information on the fabrication of shell beads and other shell ornaments. A considerable amount of stone was recovered, almost all of which is petrified wood used specifically in the production of “microdrills” for perforating shell beads. Also recovered were large quantities of fragmented knobbed whelk (Busycon carica), the principal raw material used for shell beads, as well as examples of shell beads in all stages of manufacture. The excavations of this midden, designated the Bead Maker’s Midden, produced abundant information bearing on shellworking technology, including the full range of tools and raw materials used and the sequences involved in the production of shell beads. Replication experiments were conducted to validate the archaeological findings. The collected data provide direct evidence of the process of shell bead production during the Late Mississippi period.     

Oxygen isotope analysis of California mussel shells: seasonality and human sedentism at an 8,200-year-old shell midden on Santa Rosa Island,California

To evaluate coastal settlement and land use strategies among maritime hunter-gatherers, we analyzed oxygen isotope (δ¹⁸O) data from 131 marine carbonate samples from 21 California mussel (Mytilus californianus) shells obtained from a large ～8,200-year-old shell midden (CA-SRI-666) on California’s Santa Rosa Island. Seasonal distributions of the isotopic data were assigned using a paleo-sea surface temperature model created by comparing modern sea surface temperatures (SST) to a fully profiled ～8,200-year-old shell. For 20 additional shells, we used two sampling strategies to compare season-of-harvest inferences and explore whether the Early Holocene site occupants were sedentary. Estimated season-of-harvest differed by 35 % between the two sampling methods, corroborating recent isotope analysis of an 8,800-year-old shell midden on San Miguel Island. Shellfish appear to have been collected year-round at CA-SRI-666 from intertidal or subtidal water temperatures similar to modern SST in the vicinity of eastern Santa Rosa Island. The isotope results are consistent with other evidence from CA-SRI-666 that suggest that the site served as a residential base for relatively sedentary maritime people.     

CONTINUING THE RESEARCH: ARCHAEOGEOPHYSICAL INVESTIGATIONS AT THE BATTLE MOUND SITE (3LA1) IN LAFAYETTE COUNTY,ARKANSAS

Abstract

The continuing use of archaeogeophysical methods at the Battle Mound site (3LA1) exemplifies the power of geophysics as a non-invasive, preservation-oriented, and economically feasible way to pursue the exploration of settlement patterning at the Middle and Late Caddo (ca. A.D. 1200–1680) mound site. Using these methods, a 1-ha (2.47 acres) area directly east of the large mound was surveyed using magnetic gradiometry and concatenated to the existing survey area. Results from the 1-ha survey provide further elucidation of the spatial structure and internal organization of the Caddo Indian occupation at the Battle Mound site.     

Exploring Accumulation Rates of Shell Deposits Through Seasonality Data

Shell middens are often analysed as the result of short- or long-term depositional activities. In order to confidently interpret such deposits, it is necessary to have accurate estimations of shell accumulation rates, most commonly produced by radiocarbon dates. This paper introduces the application of seasonality data as a temporal measurement of short-term shell deposition. This gives access to an additional estimate of shell accumulation rates, which work on a shorter timescale than can be analysed through radiocarbon dating. We focus on shell deposits on the Farasan Islands, Saudi Arabia, which comprise over 3000 shell midden sites dating to the mid-Holocene (6500–4500 calBP). One site (JW1727) was chosen to (1) explore the potential of seasonality data to reconstruct accumulation rates, (2) analyse the intensity of exploitation and (3) assess the visibility of short-term shellfish deposits. Stable oxygen isotope values (δ¹⁸O) were obtained from the marine gastropod Conomurex fasciatus (Born 1778), representing 72 % of the shell weight of JW1727, to reconstruct season of capture. Seasonality data was grouped by their spatial distribution, which allowed successive episodes of deposition within a stratigraphic sequence to be connected. This allowed us to make an estimation of exploited shell meat of ～200 kg over a 7-month period (～400 shells/day). We argue that excavation methods and low resolution stratigraphic data cause imprecision in the seasonality data and the low visibility of rapidly accumulated shell deposits. Also, an increase of analysed shells per layer is key to understanding the seasonal brickwork of more middens in the future.     

The Case of the Caldwell Mound: A Woodland Period Mound in the Central Scioto River Valley

ABSTRACT

This article presents a reconstruction and analysis of the Caldwell Mound located in the central Scioto River valley of southern Ohio. The mound contained a log tomb, at least four burials, and associated funerary objects. Four AMS radiocarbon dates place the Caldwell Mound within the last century BC and first century AD, and the mound contains evidence of practices historically associated with “Adena” and “Hopewell.” Few other records exist from this period in the region despite it experiencing perhaps some of the most dramatic socioreligious transformations in precolumbian North America. This analysis documents early evidence for the diversification and segregation of leadership roles based on the interpretation of three buried individuals. It also demonstrates the utility and efficacy of working with amateur-produced records and collections, even when incomplete, to reconstruct and glean insight from important Woodland period sites.     

Mound ZZl,Nixtun-Ch'ich', Petén,Guatemala: Rescue Operations at a Long-Lived Structure in the Maya Lowlands

Abstract

Mound ZZl, located on the tip of the peninsular portion of the large lowland Maya site of Nixtun-Ch’ich’ in Petén, Guatemala, was investigated in 2007 during a salvage operation. An axial trench revealed a long sequence of activity in the area, beginning before 1000 B. C. and extending into the early 18th century. Early platform construction was accompanied by feasting and smashing of Middle Preclassic (1000—400 B.C.) pottery in a termination and/or dedication rite. The mound grew through the construction and reconstruction of numerous platforms and structures—and further episodes of termination and dedication—that primarily extended it laterally, rather than vertically. The location of Mound ZZl and its features—reincorporation of Middle Preclassic fill materials; secondary burials; clay figurines; protection by a large wall-ditch complex; pecked plaster symbols; and the presence of a Spanish mission church—suggest that it was a key civic-ceremonial component of the region's sacred landscape for nearly three thousand years.