This modest award assists Professor Paul I. Abell of the University of Rhode Island to collaborate in paleoclimatology research with Professor Hans-Joachim Pachur of the Institute for Physical Geography of the Free University of Berlin, FRG. The objective of their current research is to assess the degree to which stable isotope analyses of the shells of ancient freshwater gastropods by Dr. Abell give the same interpretation of paleoclimates as the geological/paleon- tological approach used by Dr. Pachur. The shells were collected by Dr. Pachur from sites along a mid-Holocene Saharan river bed in the northern Sudan, where he has been applying a variety of techniques to the delineation of ancient climatic conditions. Shell material will be jointly selected from his collections, and Dr. Abell and his students will measure stable isotope ratios on these shells at short intervals along the growth spirals. The environment in which man evolved in Equatorial Africa has been the subject of extensive interest and study by anthropologists, archeologists, paleontologists and climatologists. It has become evident that climate may have been a significant factor in directing evolutionary change, both morphologically and socially. The measurement of stable isotope ratios in freshwater gastropod shells may provide a valuable new tool in the armory of those scientists interested in the Pliocene-Pleistocene-Holocene world. Comprehensive comparison and interpretation of the isotope and geological and paleontological data produced in this collaborative project will test the validity of the stable isotope approach and provide useful research experience for several U.S. undergraduate and graduate students.
