HR: 14:05h
AN: U13A-02 INVITED     [Abstracts]
TI: Late Cenozoic Moisture History of East Africa
AU: * Trauth, M H
EM: trauth@geo.uni-potsdam.de
AF: Institut fuer Geowissenschaften, Universitaet Potsdam, POB 601553, Potsdam, 14415 Germany
AU: Maslin, M A
EM: mmaslin@geography.ucl.ac.uk
AF: Dept of Geography, University College London, 26 Bedford Way, London, WC1H 0AP United Kingdom
AU: Deino, A
EM: al@bgc.org
AF: Berkeley Geochronology Center, 245 Ridge Road, Berkeley, CA 94709 United States
AU: Strecker, M R
EM: strecker@geo.uni-potsdam.de
AF: Institut fuer Geowissenschaften, Universitaet Potsdam, POB 601553, Potsdam, 14415 Germany
AB: Evidence from fluvio-lacustrine sediments in ten separate basins in the Ethiopian and Kenya rifts suggests there were three protracted humid periods during the Late Cenozoic; at 2.7 - 2.5, 1.9 - 1.7, and 1.1 - 0.9 million years before present. These wet periods are coeval with known increases of aridity in parts of North West and North East Africa, indicating significant regional shifts in African climate. These three East African wet periods correspond to major global climatic changes as well as maxima in eccentricity and thus precession, suggesting a combined global and local causation. These climatic changes were important for the speciation and dispersal of mammals and hominids in East Africa as it implies that key steps in human evolution occurred during relatively humid periods in a region containing extensive deep lakes.
DE: 1655 Water cycles (1836)
DE: 1620 Climate dynamics (3309)
DE: 1645 Solid Earth
SC: Union [U]
MN: 2004 AGU Fall Meeting