"Diane Gifford has observed periods of sediment accumulation on contemporary
sites at Lake Turkana and has found that, at time, accumulation is very rapid.
These observations have formed part of a study of how bones and stones enter
the fossil record. At the end of September 1972, she had the opportunity of
watching the fate of a butchery site occupied by a small group of Dassanetch
hunters who killed a hippopotamus on the lakeshore. Because of the size of
the carcase the men established a short-term camp about 60 metres (200 feet)
inland from the kill. They carreid most of the carcase to their camp, where
they constructed two rock windbreaks and a stone-circled hearth. The group
stayed there just a few days before moving on and leaving the debris of their
camp-site, including the scattered bones of the hippo, behind them.
"The lake was rising at the time, and very soon the head and neck of the
carcase was standing in shallow water while the rest of the scattered skeleton
was exposed on dry ground. The rise continued through to December of the
following year, and then reversed. Finally the head and neck were again
exposed above water, revealing a 3-centimetre (1-inch) layer of fine silt in
and around the skull. This, together with the water, had served to preserve
the bone. By contrast, the parts of the skeleton not covered by water had
begun to crack and flake from exposure to the elements. This illustrates both
the speed with which bones can be buried along a lake margin and the rapidity
with which unprotected bone will begin to disintegrate." Richard Leakey, The
making of Mankind, (E. P. Dutton, 1981), p. 35.
The interesting thing to me was the windbreak which I mentioned last night,
and the earliest one is from 2.0 million years ago and the stone-circled
hearth which was like that found at Terra Amata, 300-400 thousand years ago.
I will answer Joe Riemer's question tonight, and then I will be gone for a
week much to the relief of some. I am going to go see Redwoods. I have never
seen that type of tree and I want to see if the reports are a impressive as
advertised. I hope to go to Chinatown in San Francisco and practice my
chinese(or make a fool of myself).
glenn