Pech de l'Azé IV Layer 8

The Pech de l'Azé IV Layer 8 project grew out of the earlier excavations (2000-2003) of the site. At the base of the sequence is a thick layer (Layer 8) of dark deposits that document Neandertal use of fire at the site. In addition to intact hearths, the layer contains a very high percentage of heated lithics and bones. Interestingly, evidence for fire in the overlying layers drops off rapidly, and fire is poorly attested to in the rest of the sequence.

At the time, we tried two different techniques to expose the hearths to have a better idea of their extent and spatial configuration. At first we tried to expose them horizontally through aerial excavation. The difficult, however, was that the hearths were subject to extensive rack-out and trampling meaning that the deposit that contains them looks quite similar to the hearths themselves. As a result it was extremely difficult to follow them in an aerial excavation. Next, because the Layer 8 hearths are often readily apparent in sections (especially when photographed under the right lighting conditions), we tried to excavate a band of Layer 8 in ten centimeter slices. However, here again after a couple such slices we abandoned the effort. Even with narrow slices, it was too difficult to follow the stratigraphy from one slice to the next. Thus we closed the site in 2003 leaving behind a large portion of the Layer 8 deposits for further research.

Then in 2016, Harold Dibble, Dennis Sandgathe, Paul Goldberg and Vera Aldeias decided to try again with a completely different methodology specifically adapted to these hearth features. They proposed to remove narrow slices from the site and excavate them instead in the lab under very controlled conditions and using a vacuum system to capture all sediments into sterilized vials for analysis. In this way, multiple consecutive slices could be excavated simultaneously allowing their stratigraphy to be documented and compared at a micro level. Additionally, every fourth slice would be retained as a large micromorphology block. This project was funded by the National Science Foundation, and work began in 2017 with the first tests of methods for removing the blocks. Tragically, Harold Dibble died before the planned 2018 season. Afterwards, the project was then reorganized to include Deborah Olszewski and Shannon McPherron. In 2019 we conducted our first proper season with the excavation of two blocks and the removal of others. In 2020 we were unable to excavate due to the global pandemic. Currently, we are planning a full season with the excavation of four more blocks for the summer of 2021.