Collaborative Research: Development and Application of Cryptotephra Studies to Resolve Debates over Chronology in Modern Human Origins Research in South Africa

Collaborative Research: Development and Application of Cryptotephra Studies to Resolve Debates over Chronology in Modern Human Origins Research in South Africa Collaborative Research: Development and Application of Cryptotephra Studies to Resolve Debates over Chronology in Modern Human Origins Research in South Africa Cryptotephra shards discovered at Pinnacle Point (PP5-6) at the southern tip of Africa correlate with the 74 ka Toba super-eruption (YTT). YTT cryptotephra has also been found in the Lake Malawi core. Since YTT has been discovered to the north in Malawi and on the far south coast, we fully expect to find it in all the key early modern human archaeological sites in South Africa. These results will significantly improve our understanding of the timing of the origins of modern humans, resolve a recently-developed dating debate, and correlate these important records of modern human origins within a global network of sites at a single moment in time. YTT will act as an isochron for high precision correlations to global chronologies and paleoclimate records. The objective of this project is to provide modern human origins studies in South Africa with a new and independent dating technique, resolve a current dating debate over the age of indicators of early complex and symbolic behavior, and use the discovered cryptotephra results to provide precise chronological tie-points between these crucial sites, other regions (for example East Africa), and the global climate change record. This collaborative project will 1) develop the cryptotephra correlation dating method specifically for application to southern Africa and the dating of key events in modern human origins research, with the longterm goal of applying it to other sites in Africa, 2) sample a set of sites crucial to modern human origins for the Toba cryptotephra, define it geochemically, and identify where in the sections the shard peak is found, 3) conduct exploratory research with the goal of identifying other cryptotephra markers from volcanoes in other regions for the purpose of dating other portions of the sections. The methods include 1) the collection of sediment samples from each of the archaeological sites, 2) heavy liquid separation of the shards for analysis, 3) geochemical characterization of the shards and correlation to known eruptive events, and 4) counting of shards to identify the peak of shard counts in the stratigraphy of the sites.