HR: 13:45h
AN: U13A-01    [Abstracts]
TI: Complex Records of Environmental Character and Change in Neogene African Rift Basins
AU: * Feibel, C S
EM: feibel@rci.rutgers.edu
AF: Dept. of Geological Sciences, Rutgers University, Wright Geological Laboratory 610 Taylor Road, Piscataway, NJ 08854-8066 United States
AB: The Neogene rift basins of East Africa preserve complex environmental records encompassing the effects of tectonics and climate along with the influences of volcanism, landscape succession and biotic change. Detailed reconstruction of individual basin evolution, along with the integration of parallel basin histories can allow the isolation of controlling factors, particularly when they are represented by distinctive signatures. Major Neogene basins, such as the Turkana and Middle Awash systems, preserve long and detailed records, with critical correlation links based on tephrostratigraphic ties, isotopic age determinations and magnetic polarity stratigraphy. Smaller basinal systems, such as Olduvai, Konso and Olorgesailie often reflect shorter accumulation histories, but may add crucial data for distinguishing the influence of global climate, regional tectonics, and local environmental effects. Miocene sedimentary records provide important baseline data on environmental conditions across the African continent, including major tectonic effects initiating subsidence along with strong local climatic influences. Plio-Pleistocene records are far more complete, and demonstrate both short-term (seasonal) as well as long-term (Milankovitch scale) climatic influences superimposed on regional tectonic controls and episodically overwhelmed by explosive volcanic signals. Depositional and post-depositional features of these sedimentary sequences directly reflect habitat character and change through crucial intervals of development in African terrestrial ecosystems. These continental archives preserve direct evidence of the environmental patterns which influenced crucial steps in hominin evolution, the appearances, adaptation, behavioral innovation and extinctions of the hominin clade.
DE: 9305 Africa
DE: 8110 Continental tectonics--general (0905)
DE: 3344 Paleoclimatology
DE: 4239 Limnology
SC: Union [U]
MN: 2004 AGU Fall Meeting