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Research Fellows Directory

Nicholas Blegen

Dr Nicholas Blegen

Research Fellow


University of Cambridge

Research summary

My research focuses on understanding modern human origins through the studies of volcanic glass (obsidian) and volcanic ash layers (tephra) from the last 500,000 years in East Africa. This work entails establishing the geographic scale of prehistoric human interactions via stone raw material sourcing and refining the stratigraphy and chronology of correspondingly vast landscape-scale archaeological, paleontological and geological deposits through correlation and dating of tephras. Long-distance transport of stone materials is a feature of prehistoric human behavior that is important for determining the geographic scale of human interactions with their physical environments as well as with one another. Using geochemical sourcing of obsidian artifacts at sites from equatorial East Africa, I am able to document this behavior. With new excavations and artifact analysis my work is showing that prehistoric hunter-gatherers from at least 400,000 years ago regularly transported obsidian distances between 50 and 250 km. This behavior was not previously documented at sites dating to more than 60,000 years ago. To establish a chronology of geographic scale matching the large range over which our early modern human ancestors traversed, I use geological survey and chemical analysis of volcanic ashes dispersed across equatorial East Africa. Such work has documented many widespread ash layers, some found across an area of over 115,000 square kilometers and correlating across several East African rift basins. All these rift basins contain rich archaeological, fossil and paleoenvironmental archives. These tephras thus provide the context with which to characterize past landscapes and environments relating to human behavior and interactions on large geographic scales commensurate with the scope of human interactions documented by raw material sourcing. These themes are encompassed in my current research as part of the "Ashes of Our Ancestors: project. this work will assess the relationship between behavioral change and past environments in East Africa over the time scale of modern human evolution by linking archaeological sites to paleoenvironmental data through the correlation and dating of widespread volcanic ash layers.

Grants awarded

The Ashes of Our Ancestors: Dating the Circumstances of Modern Human Evolution in East Africa.

Scheme: Newton International Fellowships

Dates: Oct 2018 - Sep 2020

Value: £99,000