Today is a well deserved day off for the crew, as we have put in a long week of hard work. We thought that a report of the state of our excavations would be appropriate.
At
Site A11-10, overburden removal continues. We are expecting to hit the target
layer soon. Although we expected the work to take a long time, due to the
quantity dirt, progress was complicated this week by an unexpectedly hard
layer in the sediments above our target sand. The diatomite layer was particularly
well cemented; usually it will break readily. In fact, it bent one of our
picks.
The
Locality B excavation is nearing completion already, as the Member 8 layer
has nearly been completely removed, and all of the fossils have been carefully
exposed. Preservatives applied to the fossils will keep them from disintegrating,
and we will extract them on Monday or Tuesday. One of the reasons we needed
to set up a datum in Locality B is to allow us to remove the bones from this
site. In order to remove fossils, we need to be able to record their position
on our grid. So far, a preliminary analysis of the bones is indicative of
a single individual, a large grazing animal. A more detailed study will have
to wait until we are out of the field and back in the museum lab.
At
Site 15 (the Elephant Site) we have nearly reached the target paleosol. Excavation
continues in 5 cm spits and the excavators continue to careful pick through
the sediments for fossils or stone artifacts. The microfauna fossils which
are being recovered from the sediments are aiding our research on environmental
change in the Olorgesailie Basin 990,000 years ago. Careful study of microfauna
above the elephant layer coupled with our data on the environment during the
time of the elephant layer will give us insight into any environmental change
that took place and the rate at which it took place.
-RP