Understanding whether and how Earth system processes impacted human evolution is a challenge that generates broad interest among scientists and the general public. A recent NRC report noted how understanding of the environmental dynamics underpinning human evolution is ripe for major advances. This grant brings together scientists with a breadth of expertise, and this team will expand the paleoenvironmental data set upon which hypotheses about the relationship between environment and human origins must be based. The team will recover cores from long drill cores from five carefully selected ancient lake beds in Ethiopia and Kenya. These sites cover several important intervals of the late Neogene and Quaternary, close to key paleoanthropological sites, that will provide important new environmental information about the locales inhabited by ancient hominins. Funding requested here will support operational costs related to drilling and the initial core descriptions.
The goal of this project is to produce high-quality paleoenvironmental data from deposits close to key anthropological sites. Drilling allows the collection of unaltered samples from the same beds producing the hominin fossils, These near-pristine samples contain geochemical proxy data that can be used to decipher the region's environmental history. The team will correlate these drill cores to nearby marine records and to nearby outcrop records containing hominin and other vertebrate fossils, and to artifact assemblages by using tephras, paleomagnetism and other direct dating techniques. Drill cores from distal ancient lake beds avoid outcrop sample problems such as weathering, lacunae, and discontinuous expression of paleoenvironmental variables, while allowing examination of seasonal-scale environmental variability in varved intervals. The project will collect ~2400m of cores from nine bore holes at the North Awash and Chew Bahir Basins in Ethiopia, and the West Turkana, Baringo and Magadi Basins in Kenya. These areas have yielded some of the most important fossil hominin and artifact sites in the world, directly stimulating much of the current debate about human evolution and environmental dynamics. All sites contain long, continuous climate records spanning much of the last 4 million years, and are areas which are demonstrably sensitive to a range of environmental forcing mechanisms. The cores will be ideal for generating quantitative paleotemperature, paleoprecipitation, and other environmental reconstructions critical for understanding the environmental dynamics that early hominins experienced. These data will also provide a strong empirical base for evaluating both large and mesoscale models of African paleoclimate, and models linking climate, orography, hydrology and vegetation resources critical for early hominin survival.
The project includes training opportunities for nine American and African students, including focused outreach efforts to attract U.S. under-represented minority undergraduates through the University of Arizona's Saguaro Program. Many Kenyan and Ethiopian scientists are centrally involved in the project, and training and research opportunities will exist for more junior African scientists at all stages of the project. Public outreach activities will be carried out through three museum partners in the US and Africa. In the past, the local communities have benefited from scientific drilling activities by casing the boreholes so that they can be used as water wells.
Core samples and data collected by this project will be available to the general scientific community through the National Lacustrine Core Laboratory, ICDP NGDC, and the Smithsonian's Human Origins Database. The drilling operations will be co-funded by the International Continental Drilling Programme.