Rockshelters can serve as important prehistoric settlements that commonly preserve stratified archaeological materials; however, few geophysical surveys have proven successful in these environments. We carried out a 2D GPR survey at Mochena Borago Rockshelter, an archaeological site located in southwest Ethiopia. Here, we present the processing and interpretation methodology of the GPR dataset and describe its impact on the understanding of the site. Data processing included DC-drift removal and time-0 correction, as well as post-processing steps including background, band-pass, and f-k filtering. Across some 2D profiles, the GPR signal was contaminated with high amplitude above surface diffractions, spurious signals generated from the rockshelter walls and ceiling. Separating these from subsurface reflections posed a challenge that we’ve attempted to overcome during processing. Interpretation was carried out by mapping major reflection packages and grouping these into radar facies. We then compare these with geologic facies defined by stratigraphic descriptions examined in the excavation units. Finally, we mapped the deepest coherent, laterally extensive reflection as the basement, which appears significantly deeper than any excavations at the time of writing (upward of ~4-m) in some areas of the shelter. We conclude that GPR provides a valuable dataset to understand the nature of stratigraphic deposits at Mochena Borago. The success demonstrated here supports further geophysical work at Mochena Borago and other rockshelter sites in Ethiopia and elsewhere around the world.
Presentation Date: Wednesday, October 14, 2020
Session Start Time: 9:20 AM
Presentation Time: 10:10 AM
Location: Poster Station 5
Presentation Type: Poster
