Observations on the stratigraphy and rediometric age of the omo beds, lower omo basin, southern Ethiopia

During September and October, 1966, the author measured a stratigraphic section for a portion of the Omo Beds, as exposed north of Kalam, Ethiopia. Additional field observations were also made at the time in other parts of the lower Omo Basin. Samples were collected for analysis and for radiometric age determination, and the first potassium-argon measurements were made on feldspars from tuffs in this succession in late 1966 and early 1967. As part of the work of the University of Chicago contingent of the Omo Research Expedition, further field work was possible in the main exposures during the summer of 1967, with additional units being added to the stratigraphic section recorded previously. Materials suitable for isotopic age determination were recollected and further potassium-argon measurements were made during the fall of 1967. These results substantiated and extended the earlier findings.