Dr. Nancy Sikes will conduct carbon and oxygen isotope analyses on soil samples collected from four important paleoanthropological sites in East Africa. She will run ca. 250 samples, including 40 standards and duplicates and use this information to assess habitat diversity and change in environments occupied by hominids in the East African Rift system. These data, supplemented by traditional analyses of sediments, pollen and fauna will enable scientists to examine the relationship between hominid cultural and biological development and the variable and changing environments in which they lived. Stable carbon isotope analyses will allow estimation of the proportion of tropical woody plants in relation to more open country grassland species. In this way it is possible to distinguish between grassland and woodland habitats. Oxygen isotope ratios from soil carbonates will be used to reconstruct changes in local and regional climatic conditions, particularly temperature and rainfall. The four sites to be studied include: 1. the Chiwondo beds of Northern Malawi. These are associated with two species of early hominid and date to 2.3-2.5 million years ago (mya). 2. At Olduvai Gorge Dr. Sikes will examine a single strata which dates between 1.75 and 1.70 mya and has been the focus of extensive anthropological investigation. 3. At the younger site of Olorgesailie she will focus on sediments which span the 1.2-0.049 mya sediments in areas which have yielded archaeological remains. 4. Finally she will study a ca. 1.6 my artifact rich paleosol at the site of Peninj in northern Tanzania. Paleoanthropologists have recovered extensive fossil and artifactual remains from sites in Eastern Africa and on this basis traced, in general outline, changes in hominid culture and physical form over a four million year period. However the causes for these changes and the environments in which they occurred are poorly understood. Many scientists look to the environment which in Eastern Africa underwent extreme alternations between drier and wetter conditions as an explanatory factor. Dr. Sike's research will provide important insight into conditions at sites of particular paleoanthropological significance. - À- v- +- ±@ + _ Ûª? ÑOh ª' +'ª?0 à + Õ $ H l + ¢ ? D h + R:WWUSERTEMPLATENORMAL.DOT
