9700870 Walter In 1992, Eritrea emerged as an independence nation after a thirty year war. In June 1993, we contacted colleagues at the Earth Science Unit, University of Asmara concerning the feasibility of beginning geological and paleontological research in Eritrea. At their invitation, Walter visited Eritrea in July 1994 and met with the University of Asmara, the Geological Survey, the Ministry of Mines and Energy, the National Museum, and the Ministry of Culture. This paved the way for a reconnaissance field survey in the summer of 1995. A field permit was granted in March, 1996 (Attachment 1). We propose to investigate the Danakil Depression of Eritrea, which is the northernmost segment of the Afar Rift system, itself a major branch of the East African Rift. Specifically, we will investigate the northern Danakil Depression, the escarpments adjacent to the Depression, and the sedimentary basins along the Red Sea coast north of the Danakil (Fig. 1). Our primary objective is to study the origin and evolution of tectonism, vol.canism, and sedimentation in an area where oceanic and continental rift processes merge. We are specifically interested in the interplay between voicanism and tectonism as they relate to sedimentary basin formation, and the correlation between terrestrial and marine sequences. A secondary objective is to survley the rift basins for hominid-paleontological and archaeological occurrences. Results and observations from this study will provide insights into early hominid evolution in Eritrea. In a broad sense the project concerns the first systematic survey of late Cenozoic sedimentary basins in Eritrea for their integrated geological, paleontological and archaeological content. This proposal seeks funds to partially support an exploratory field project to begin January, 1997. Investigators in this preliminary phase are: (1) Richard Buffler (University of Texas, Austin; sediment basin analysis, regional tectonics); (2) Seife Behre (Eritrean citizen, in priva te consulting in Eritrea; remote sensing, regional tectonics); (3) Tesfaye Yemane (Eritrean citizen, Ph.D. candidate, Iowa State University; sedimentology and stratigraphy); (4) Twiede Medhin Tecle (Eritrean citizen; Eritrean Ministry of Mines and Energy; regional geology); (5) Semere Solomon (Eritrean citizen; University of Asmara; structural geology; (6) Carl Vondra (Iowa State University; stratigraphy, sedimentology, rift basin analysis) and (7) Robert Walter (Institute of Human Origins, geochronotogy, volcanology, regional tectonics). Partial support is provided by a grant from Anadarko Petroleum Corporation (Budget). This is a preliminary project in an area that has only recently been opened to scientific investigations. One of our goals is to test a sequence stratigraphic approach to terrestrial basin analysis. Stratigraphic sections will be subdivided into a regional framework using laterally extensive chronostratigraphic markers, including unconformities (base level falls, down cutting), flooding events (base level rises, aggradation), and interbedded volcanic units (flows and tephra beds) that witl be radiometrically dated. Several unconformities and numerous volcanic units were observed during a reconnaissance survey to this area in 1995. An attempt will be made to identify sedimentary cycles within adjacent marine and nonmarine sections, and to relate them to sea level and climatic base-level cycles, and to use them as correlation tools. We will use this information to test models of rift evolution. Our secondary objective, to identify potential hominid-bearing paleontological sites, is also a testable hypothesis. The prospect of early hominid fossils in the Dana.U was initially theoretical, based on the hypothesis that the sedimentary basins of northern Afar formed under similar tectonic, geological, and paleoenvirom-nental conditions as hominid-bearing deposits of the central Afar, where several geological and anthropological research groups (including IHO's Hadar Research Project) have been working for nearly twenty years. However, in December 1995 a hominid skull (species uncertain) was found by an Italian geological research team (led by E. Abbate of the University of Florence) in Plio-Pleistocene sediments near Buia along the flanks of the Danakil Depression. Their discovery is significant for it shows that early hominids are indeed present in the late Cenozoic sediments of the Danakil basin, and that this secondary objective has a high probability of success. The project merits consideration as a Small Grant for Exploratory Research because it is preliminary work on untested and novel ideas (e.g., terrestrial sequence stratigraphy and early hominid exploration). There is also an urgency to conduct field work, since the Eritrean government may not hold the permit indefinitely. Preliminary 4OAr/ 39Ar dating of volcanic rocks collected during this study will be done at the University of Toronto by RCW in the laboratory of Prof. Derek York.
