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.
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.
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.
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.
-RP