The Great Rift Valley covers 8,700 Kms. (5,400 miles) running from Jordan Valley in the Middle East and taking in the whole of the Red Sea before cutting through Ethiopia, Kenya, Tanzania, Mozambique and finally reaching the Indian Ocean at Beira. The valley is lined with a series of freshwater and soda based volcanic lakes .The high rate of evaporation is the only major way through which water escapes from the lakes. The evaporation leaves behind a large accumulation of salts and minerals in the lakes. This makes the lakes Naivasha and Baringo contain high alkaline contents, a factor that makes the highly alkaline soils in and around the lakes turn bones and ivory into fossils.