Dr. C. Vance Haynes and collaborators will examine geological sections in 16 U.S. archaeological sites which bracket the Pleistocene-Holocene transition which occurred from ca. 11,500 to 10,500 years ago. During three seasons of fieldwork they will conduct geologic mapping and microstratigraphic recording in sufficient detail to understand the processes and origins, and to provide a precise stratigraphic framework for sampled sediments, fauna, pollen, diatoms, artifacts and radiocarbon samples. Pollen and diatom analyses will be conducted by appropriate specialists and a large number of samples will be dated to a precision of +- 80 years by radiocarbon accelerator mass spectrometry. This research will provide increased insight into the climatic and environmental changes which marked the end of the last Ice Age and the response of humans as well as other species. Archaeological evidence clearly indicates that humans were present in North America prior to the end of the last Ice Age. These groups, known as "Folsom", which is the name of a specialized stone point type they employed, were widely distributed and hunted species such as mastodon. However, within what appears to be an extremely limited interval a transition occurs and "Clovis" peoples first appear in the archaeological record. At about the same time, several other changes seem to take place as well. Preliminary evidence indicates climatic drying and the rapid extinction of many species. While a number of archeological sites exist which span this interval, it is difficult to compare across them because of varying analytic techniques employed. The work by Dr. Haynes and his colleagues will provide the basis for synthesizing large amounts of data from these individual sites. It will also allow him to test his hypothesis that a rapid and marked reduction in rainfall was responsible for associated environmental and cultural changes. This research is important because it will shed light on a poorly understood aspect of U.S. prehistory. It will also increase our understand of climate change and human and other animal response to it.
