T327 Paleoclimate Proxies and Evolving Human Landscapes

Wednesday, 30 October 2013
8:00 AM - 12:00 PM
Room 605

THE HOMININ SITES AND PALEOLAKES DRILLING PROJECT (HSPDP): DOCUMENTING THE PALEOENVIRONMENTAL CONTEXT OF HUMAN ORIGINS IN EAST AFRICA THROUGH SCIENTIFIC DRILLING

Paper number: T327-12
Program: Technical Sessions
Time: 10:40 AM – 10:55 AM

Authors

Abstract

Testing hypotheses linking environmental change and human evolution requires detailed climatic, tectonic and hydrographic records for the areas of interest. In eastern Africa, stratigraphically continuous lake beds often occur near important fossil hominin and artifact sites, providing an opportunity to reconstruct paleoenvironmental conditions at high temporal resolution for the regions where the hominins have been found. HSPDP was developed to collect high quality drill cores of these records, unaffected by surface weathering, from some of the most important fossil hominin and artifact localities in Kenya and Ethiopia. The five drilling areas under study are (oldest to youngest): 1) The Late Pliocene Northern Awash River Basin, Ethiopia, where lake beds of the Hadar Fm. will provide an environmental record through the evolutionary history of Australopithecus afarensis; 2) Pliocene deposits of the Chemeron Fm. in the Tugen Hills, Kenya, which have yielded the oldest fossils of Homo; 3) Early Pleistocene lakebeds of the Nachukui Fm., west of L. Turkana, Kenya, coeval with rich archaeological finds, where some of the earliest and most complete specimens of H. erectus have been found, and covering the time window when hominins first dispersed out of Africa; 4) Chew Bahir, Ethiopia a modern but seasonally dry Middle Pleistocene-Recent basin near the oldest known fossils of anatomically modern H. sapiens, and, 5) The Lake Magadi Basin, Kenya, where a M. Pleistocene-Recent record adjacent to key archaeological sites will document environments during the technological transition into the Middle Stone Age.

Drilling at the Tugen Hills and W. Turkana sites took place in June-July 2013. Cores at the Tugen Hills (~228m) and West Turkana (~216m) sites both had excellent recovery (>93% each). Down-hole and preliminary multisensor core logs, along with field core observations indicate considerable paleolake level and environmental variability. Drilling at the Ethiopian sites will take place from November 2013 to February, 2014 and at L. Magadi in mid-2014. An extensive suite of paleoecological, geochemical and physical properties analyses, along with climate/landscape modeling experiments will be conducted following the coring phase.

Authorship of this abstract also includes the entire HSPDP field team.