AGE OF BED I, OLDUVAI GORGE, TANGANYIKA

Olduvai Gorge is justly famous because of its unique geological sequence of Pleistocene deposits, which are exceedingly rich in fossil fauna, as well as a long sequence of stages of evolution of the earlier Stone Age cultures.

In the monograph published in 1951 the view was expressed that, although Bed I differed from Bed II in faunal content, both belonged to the lower part of the Middle Pleistocene. This view was revised by one of us in 1959 as a result of reviewing the fauna collected in the series of detailed excavations during the period 1952–9 inclusive.

Leakey claimed that it was now apparent that the time-interval between Bed I and Bed II was greater than had been previously supposed, and he reverted to the view which he had published in 1935 that Bed I was of Lower Pleistocene age. In view of the extraordinary wealth of fossil and cultural material in the Olduvai deposits, it was not surprising when in 1959 a most important fossil hominid skull—Zinjanthropus boisei—was found in Bed I, at site FLK I, in association with faunal remains and Stone Age Culture material of the Olduwan Culture. In 1960, thanks to the Research Committee of the National Geographic Society, the Wenner Gren Foundation and the Wilkie Trust, very extensive further work was carried out, resulting in the discovery of pre-Zinjanthropus fossil hominid material at a lower geological level in Bed I.