Skip to main content
U.S. flag

An official website of the United States government

New geochronologic and palaeomagnetic data for the hominid-bearing Hadar Formation of Ethiopia

January 1, 1977

A 2.6 Myr K/Ar age has been derived for a primary unreworked tuff high in the hominid-bearing Hadar Formation (Kada Hadar Member), stratigraphically above all the important fossil finds. A 2.6 Myr fission track age has been derived on zircons from this tuff. New K/Ar results on the Kadada Moumou basalt (Sidi Hakoma Member) suggest a 3.0 Myr age. Preliminary interpretation of a detailed continuous palaeomagnetic section through the formation indicates the existence of persistent normal and reversed sequences. With the radiometric age control this magnetic sequence appears to correlate with the Gauss Epoch. These initial results imply the fossil-rich Hadar Formation spans from somewhat older than 3.1 Myr to somewhat younger than 2.6 Myr. ?? 1977 Nature Publishing Group.

Publication Year 1977
Title New geochronologic and palaeomagnetic data for the hominid-bearing Hadar Formation of Ethiopia
DOI 10.1038/267323a0
Authors J.L. Aronson, T.J. Schmitt, R.C. Walter, M. Taieb, J.J. Tiercelin, D.C. Johanson, C.W. Naeser, A.E.M. Nairn
Publication Type Article
Publication Subtype Journal Article
Series Title Nature
Index ID 70000995
Record Source USGS Publications Warehouse