Regional Manifestations of Late Quaternary Climate Change and Archaeological Site Burial Along the South Atlantic Coastal Plain

Archaeological site investigations on the South Atlantic Coastal Plain have revealed stratified cultural remains in sand deposits of mixed aeolian and fluvial origins, aeolian sand sheets and dunes, alluvial terraces, and Carolina Bay rims. These sites are typically shallow but have yielded discernible archaeostratigraphy within sand dominated deposits by using luminescence dating (OSL), AMS radiocarbon dating, and close interval sediment sampling. Periods of site burial are linked to regional and global paleoclimate records, including Bond events, and provide broader reconstructions for human ecology and periods of site burial.

Introduction

This chapter reviews the significant features of early prehistoric occupations of the Southeastern U.S. Coastal Plain. Along with the Pleistocene age archaeological sites, salient aspects of the geology, including sea level positions, are presented. Possible Pre-Clovis sites dating from pre-LGM to late Pleistocene times are considered. Clovis is seen to have a Coastal Plain settlement focus that includes the now-drowned shelf. The dramatic onset of the Younger Dryas and its potential effects on people, including the “Younger Dryas Impact Hypothesis,” are reviewed.

Brief Overview of the Younger Dryas Cosmic Impact Datum Layer 12,800 Years Ago and Its Archaeological Utility

Chapter 8 reviews the evidence for a suspected cosmic impact over North America at the onset of the Younger Dryas climatic period with the near simultaneous extinction of classic Pleistocene megafauna and the Clovis technoculture. The impact related proxies that are used to detect the impact layer, such as spherules, silica-rich glass, nanodiamonds, carbon, and geochemical enrichment of nickel, cobalt, chromium, iridium, platinum and osmium, are considered. This layer is offered as a useful chronostratigraphic marker for recognizing the YDB boundary in the absence of other dating methods.

Paleoindians in the South Carolina Coastal Plain

The state of South Carolina is examined by the physiographic provinces of Mountains, Piedmont, and Coastal Plain using established Paleoindian projectile point types and their geographic distributions by raw materials. Foraging ranges are reconstructed. There is a substantial drop in post-Clovis point frequencies, as seen elsewhere in the Southeast, with a great increase by Dalton times. Younger Dryas age environmental changes are reviewed, with late Pleistocene flora and fauna changes noted. Starting in Dalton times, sea level rise appears to have affected settlement strategies due to the inundation of the primary resource habitats of the Coastal Plain. The Piedmont Transhumance hypothesis is offered as an explanation of these changes.

Capps

A comprehensive lithic study is provided for an unusual core and flake technology made from chert sources in southeast Alabama that are heavily weathered due to age. Named Capps technology from chert artifacts there and at the Shelley site, it is compared in detail to the Old World Levallois technology with several similarities such as disc cores. Although the assemblage is derived from a surface collection, it is substantially different from Clovis and later Holocene cores and flakes.

Migrations and the Early Human Ecology of the Southeastern Atlantic Slope

The analytic sophistication demonstrated in this volume can be traced back to pioneering works in studies of prehistoric human ecology and what is now recognized as geoarchaeology. The combining of several subfields in geology, geomorphology, hydrology, soil morphology, and advanced dating methods have resulted in the realization of many of the aspirations of the inter-disciplinary research that was advocated for in previous decades. This chapter contrasts the drainage basin morphology along the lower Southeastern U.S., with its expansive Coastal Plains stands, with the shorter river valleys in the northeast, which are controlled by bedrock. The alluvial valleys in the Southeast combined with the milder climates throughout the Pleistocene set this area of the U.S. apart for prime geomorphological and geoarchaeological studies. These regions are contrasted with landforms in the near East at similar time periods, emphasizing the value in global comparisons.

From the Savannah to the Santee River

Chapter 13 examines the evidence for Early Archaic use and settlement of the inter-riverine zone between the Savannah and the Santee Rivers, both of which are the major alluvial rivers on southern Coastal Plain of South Carolina. Heretofore little work has been done in this zone. Several large, private collections, forming a transect, are analyzed for diagnostic hafted bifaces – or various stone tools – including their raw materials. The entire Early Archaic tool kit is found in this zone, though with relatively low density sites. Based on raw material sources, a considerable going back and forth between these major rivers is indicated.

Potential Consequences of the YDB Cosmic Impact at 12.8 kya

The Younger Dryas cooling episode came about in the Northern Hemisphere in an abrupt manner atypical of deglaciation events. This cooling resulted in the Pleistocene extinctions of many genera of faunas and coincided with the disappearance of the Clovis culture. The Younger Dryas Cosmic Impact of 12.8 kya is then considered as a hypothesis that explains these dramatic and enigmatic events. As a nonlinear climate episode, the YDB Impact Hypothesis can have explanatory power in accounting for the associated environmental and cultural changes.

The Vero Site (8IR009)

Recent excavations at the famous Pleistocene Vero Site, also known as the Old Vero Man site in Vero Beach, Florida, have documented strata ranging in age from 22,000 to 2000 BP. Field and lab work has resulted in a detailed reconstruction of natural and cultural stratigraphy, with possible human presence at 14,000 KA. Excavations are protected year-round by a WeatherPort structure. The project is multiyear in scope with excavations continuing through 2017.

The Pre-Clovis Occupation of the Topper Site, Allendale County, South Carolina

Located in a Pleistocene terrace on the Savannah River, evidence for a Pre-Clovis occupation of the Topper site is presented including radiocarbon and OSL dating of the Pleistocene sediments. Topper is a core and flake technology with numerous examples of small tools such as bend breaks, unifaces, small blades, and abundant lithic debris from chert quarrying. It has been named the Clariant complex. Pre-Clovis at Topper is pre-LGM and one of the oldest sites in the Western Hemisphere.