THE TIMING AND ECOLOGY OF THE HUMAN OCCUPATION OF CENTRAL ASIA (THOCA): A MICROARCHAEOLOGICAL APPROACH

Central Asia has long been recognized as an early corridor of human migration between Africa and the east. Rugged terrain and low precipitation have restricted human settlement to several key river valleys, which continuously accumulate eolian dust (loess) derived from the desert regions to the north. The THOCA project aims to rejuvenate geoarchaeological research in the Obi-Mazar River basin that has been dormant since the Soviet expeditions of the 1980s. Using cutting edge dating techniques including Optically Stimulated Luminescence (OSL), Beryllium-10 cosmogenic nuclide dating, U-Th dating of soil carbonates and paleomagnetics, we are refining the chronology of human occupation over the last 1 million years. Critically, we are augmenting macro-archaeological research with microscopic geoarchaeological techniques to investigate occurrences of fire and vegetation composition with human occupations detected from organic biomarkers. Preliminary data indicate that the Soviet pedocomplex chronology will be revised older and the scope and scale of archaeological occupation, particularly during MIS23, 13, 11 and 9, exceeds previous estimates derived from artifacts alone. Furthermore, correlations between landscape-scale fires and human habitation predate the evolution of Homo sapiens, providing deep time links between hominin migration out of Africa and landscape modification. THOCA will push the frontiers of geoarchaeological investigation, developing and refining methods to better understand the long view of human history.