1999 Field Season: Day 19

July 13, 1999

We lifted artifacts and fossils today at Site 15 (the Elephant Site). Roughly thirty stone tools and bones were taken from the site. The fragmented skeleton of an antelope was identified, although an exact identification of the species will have to wait until we get back to the lab in Nairobi. Pieces of the skull and several of the long bones (legs, ribs, etc.,) and teeth were found. This was from the paleosol layer directly above that in which the fossil elephant was found.

Getting ready for the fossil and artifact lift at Site 15.

At Site B7/8-1 we began plastering the bones that were too fragile to lift last Saturday. We were able to get most of the bones in casts and extracted. However, just as we finished putting the plaster on the cluster of vertebrae and the last two ribs, a very rare rain shower started, this being the dry season. It actually remained sunny out the entire time, there was just one large rain cloud overhead that decided to dump on us. We had to think quick, or we would end-up with a lump of fossil bone, sediment and white goo. Fortunately, we had just enough plastic sample bags around. We cut them up to make long strips of plastic, and created an impromptu tarp over the fossils, which we battened down with excavated sediment. This should hold until tomorrow.

Our plastic tarps to cover the plastered fossils overnight.

The rain picked up again before dinner, this time much harder than before. No one can remember a significant rain in the month of July at Olorgesailie. But it may actually be beneficial to us. The sediments at our Locality A sites is still incredibly hard, and a little moisture may be what is needed to soften the layers up just a bit. Also, our surveying has been hampered until now by the thin coat of dust that covers everything in the basin. A rain like this evening's may help wash off that coating, making the fossils and stone tools that have eroded out of the outcrops more visible.

Work continued at the new site, Site A11-15. A fossil vertebra and tooth were spotted eroding out of the hillside from the target sand layer today at the site, which is encouraging for our tentative hypothesis about this sand layer. We are excavating through the same layer at this site that was giving the work crew at Site A11-10 such a hard time (it is a brown silty-diatomite, that is, a diatomite that has a lot of mud mixed into it). It is very hard, and the going is slow. Fortunately, A11-15 is only a 2-by-2 meter square, not the grand undertaking of A11-10.

A fossil vertebra and tooth eroding out of Site A11-15.

And finally, hand excavation has begun at Site A11-10. After more than two weeks of hammering away at the hard diatomite layers above the target sand, the crew reached the sand. In all fairness to the crew, we would like to say that on June 28, we erroneously reported "15m3" of overburden to be removed. This was a typo. The real amount removed was actually around 75m3. Immediately, a stone tool was found in the uppermost part of the target sand layer. We hope, especially after all of the hard work that has gone into clearing this site for excavation, that this is a good sign of things to come at A11-10.

Beginning the hand excavation of A11-10.
A mountain of dirt, produced by the overburden of A11-10.