Tephrostratigraphy and geological context in paleoanthropology |
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| Authors: | Craig S. Feibel |
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| Affiliation: | Craig Feibel is a geologist in the Departments of Anthropology and Geological Sciences at Rutgers University. He has conducted research on the geological context of evolution in the Turkana Basin of Kenya, and other rift valley sites in Tanzania, Ethiopia, and Israel. His work centers on stratigraphy, sedimentology, and the reconstruction of paleoenvironments. He received a B.A. in Earth Sciences from Dartmouth College, an M.S. in Geology from Iowa State University, and a Ph.D. in Geology from the University of Utah. |
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| Abstract: | The fossiliferous and artifact-rich sites of East Africa, which are central to our understanding of early hominid evolution, also preserve a detailed record of explosive volcanism. The products of these eruptions, ash, lapilli, and pumice, are collectively known as tephra. They drifted down from the skies or washed down rivers in later rainy seasons, and now provide a key to both dating and correlation, and with them the establishment of a geologic framework for evolution. While some tephra can be directly dated, particularly through mineral phases they contain, the glass component of most ashes has a geochemical fingerprint that is unique to a particular eruption. That fingerprint defines an isochronous marker, a layer in time. By identifying characteristic geochemical signatures from far-flung localities, geologists can correlate sequences, establish relationships in time, and compile long-term records from local sections. Much of our understanding of the pattern and timing of Plio-Pleistocene evolution in East Africa is based on this tephrostratigraphic framework. © 1999 Wiley-Liss, Inc. |
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| Keywords: | tephra, stratigraphy correlation geochemistry Plio-Pleistocene dating paleoanthropology |
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