Geoarchaeological research in the coastal plain portion of the Savannah River valley

Selected archaeological, stratigraphical, sedimentological, hydrological, sea level, and ¹⁴C data are considered in order to ascertain the times and rates of saltmarsh, floodplain, river swamp, and alluvial terrace development in the lower Savannah River valley. Archaeological data are emphasized in the elucidation of these developmental trends and their environmental correlates. It is concluded that the modern environments associated with the categories of archaeological sites examined (estuarine shell middens, river swamp point bar sites, raised terrace/point bar sites) are not representative of local conditions during occupation(s). Accordingly, a mid-Holocene development of lower energy depositional environments is documented, along with a corresponding shift in subsistence-settlement patterning that suggests more diffuse, or broad spectrum, socio-economic strategies. A base level (sea level) dominance on river sedimentation, even far inland from the coast, may also be indicated.     

New evidence from the southeastern U.S. for eustatic components in the late Holocene Sea levels

Changes in Holocene sea level through time have been attributed to eustatic, isostatic, and neotectonic processes. Eustatic changes imply global expression through linkage in world climate, or changes in ocean water or basin volume, while isostatic adjustment and neotectonic distortion involve regional or local geophysical parameters which must be ascertained. A Holocene sea level curve is being developed for the southeastern United States through a study of marsh stratigraphy and archaeologic sites located in marsh and interriverine areas. The curve is evaluated in light of intensive investigations of regional and local tectonic elements. Both major and some minor trends in sea level change are shown to include significant eustatic components.     

Carolina Bay geoarchaeology and Holocene landscape evolution on the Upper Coastal Plain of South Carolina

Surface water on the mainly dry, upland interfluves of the Upper Coastal Plain of South Carolina occurs currently as a sporadic distribution of shallow ponds held within Carolina bays and other small, isolated basins. At seven bays on the U.S. Department of Energy's Savannah River Site on the Upper Coastal Plain of South Carolina, we investigated Holocene changes in bay morphology, ecology, and prehistoric human activity. At Flamingo Bay, we employed archaeological survey and testing, shovel and auger testing, sediment analysis, and ground-penetrating radar to document stratigraphy and chronology of the sand rim on the eastern side of the bay. Artifact assemblage indicate changes in intensity of human use of the bay. Radiocarbon dates from a sediment core establish time scales for depositional processes at the center of the basin. Ground-penetrating radar data from the other bays indicate that the stratigraphy of all seven bays is broadly similar. We conclude that: (1) Significant modification of the bays, including rim development and basin infilling, occurred during the Holocene; (2) ponds on the early Holocene landscape were larger and more permanent than at present; (3) early Holocene climate, as indicated by both depositional processes and human activity, was not characterized by prolonged periods of extremely dry conditions; and (4) fluvial-centric models of terminal Pleistocene—early Holocene human adaptations require revision to include intensive use of isolated upland ponds. © 1996 John Wiley & Sons, Inc.     

Unusual electrical resistivity effects associated with fast-growing trees

A series of electrical resistivity profiles have been acquired in eucalyptus groves during archaeological surveys performed in Portugal. The combination of the sandy soils in the region plus the presence of high growth eucalyptus trees yielded anomalous resistivity values which were extremely high and showed large variability. Other moderate and low growth trees did not show similar unusual resistivities. We conclude that extreme caution must be exercised when interpreting data from archaeological surveys associated with unusual soils or vegetation. © 1993 John Wiley & Sons, Inc.