Abstract
Reliable radioisotopic dates on igneous material related to fossils and artefacts excavated at a hominid site are valuable to anthropologists who, aided by stratigraphy and palaeomagnetic studies, can then conduct inter-site correlations to erect an overall time scale for hominid evolution in East Africa. As more K—Ar dates become available comparisons become more secure and the time scale more accurate. With this in mind we examined the Chesowanja locality1 in the northern Rift Valley of Kenya, east of L. Baringo at 36° 12′ E, 0° 39′ N, and now report a new K–Ar age constraint of >1.42±0.07 Myr for the Australopithecus remains and the associated Oldowan tool industry. This minimum was formed by dating the Chesowanja basalt overlying the fossiliferous sediments. Previously, a K–Ar age of 0.73±0.07 Myr had been reported2 for this basalt which (1) cast doubt on an age range estimate of 1.37–1.98 Myr for the sedinifents inferred3 on the basis of a faunal correlation with the K–Ar dated tuffs of the Shungura Formation in the Omo Valley4, and (2) confused the interpretation of the geomagnetic reversal stratigraphy5.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
