By Scott Bjelland|2011-05-31T18:50:11+03:00May 31st, 2011|Comments Off on A 5 meter cliff section of lake clays exposed along the dry river Kaitio in West Turkana. The white band near the top is the KBS Tuff, a volcanic ash that fell into the lake 1.87 million years ago. The orange band in the middle of the cliff is an oxidation zone, where organic material was ‘burned out’ by chemical reactions near the Earth’s surface.