Olorgesailie

Since 1942, archaeological and paleontological excavations have uncovered thousands of artifacts of fossils at a site known as Olorgesailie, which is about 40 miles south of Nairobi, Kenya.

In 2013, the Smithsonian's Human Origins Program began the Olorgesailie Drilling Project to obtain a long-term climate record from ancient lake deposits in Olorgesailie. The goal is to understand the climate in a regions where human evolution and adaptation took place over the last million years. Olorgesailie is important for several reasons:

There are important transitions in stone tool technologies in the last 500,000 years
The origin of our humans occurred around 200,000 years ago in East Africa
Humans began migrating out of Africa ~75,000 years ago
The emergence of the modern East Africa ecosystem

My role on the project is understand the more than 30 paleosols (fossil soils) identified in the core and compare this to new work in outcrops. There are very abrupt climate shifts with laminated lake deposits directly overlying paleosols. This pattern is repeated throughout the core and outcrop. In this ongoing work, I am using both soil features and bulk geochemistry to characterize these soils, which represent prolonged dry periods.