Multiskalige Untersuchungen zur Rekonstruktion geomorphologischer Prozesse im Abri Mochena Borago (Äthiopien) und seinem Einzugsgebiet

Abstract

In prehistoric times the rock shelter Mochena Borago served as a retreat for anatomically modern humans in the southwestern Ethiopian Highlands. During the last decade archaeo-logical analyses helped to gain insight into the history of settlement of the rock shelter in the last 50 ka. Element and micromorphological analyses as well as computer-supported large scale investigations for sediment sources and transport into the rock shelter itself were carried out to understand the depositional history of Mochena Borago. The arrangement of excavation sites gives a rough overview of the stratigraphic setting, whereas the uneven distribution of the test pits leaves gaps regarding available information on the subsurface.
The trenches show interlaced deposits of volcanic and clastic origin, which are now – to some degree – put in a depositional sequence. The unconsolidated sediments show a se-quence of paleo-surfaces, as well as indications for local continuous sedimentation and spontaneous mass movements. Furthermore, indications for humid periods with high sedi-mentation rates are found which contrast to low sedimentation rates resulting from climatic and/ or morphological changes at the site. Traces of Homo sapiens are especially common in sheltered areas within the rock shelter, which are associated with sediment accumulation in the northern part of the cave. The southern part shows high energy erosion through fluvial processes which are also related to the morphological structure of the rock shelter itself and erosion features within the subsurface. Due to existing high erosion features, it is likely that sediments with archaeological findings have been removed from the cave. This has to be taken into account, because an earlier occupation at Mochena Borago is possible.
The depositional history is still not fully understood and consequently more investigations are necessary at Mochena Borago, which constitutes a research site with urgent need for interdisciplinary work on early human local history. In the future, the regional connection be-tween different paleoenvironments in southwestern Ethiopia has to be examined and more climatic archives in this region have to be involved.

Resources

• Meyer2014_MA_MochenaBorago.pdf

Bibliography

Meyer, S. (2014): Multiskalige Untersuchungen zur Rekonstruktion geomorphologischer Prozesse im Abri Mochena Borago (Äthiopien) und seinem Einzugsgebiet. University of Cologne