Calibrating the Chronology of Late Pleistocene Climate Change and Archaeology with Geochemical Isochrons
Author(s): Stanley Ambrose
This is an abstract from the "Recent Advances and Debates in the Pleistocene Archaeology of Africa" session, at the 84th annual meeting of the Society for American Archaeology.
Chronometric dating of Late Pleistocene environmental changes and archaeological sites can be refined by correlations with precisely dated volcanic isochrons, stalagmites, and marine isotope stages (MIS). Lake Malawi cores have volcanic ash from the Toba super-eruption, dated ~74 ka at levels previously dated to ~62.5 ka. Several types of core data show an extremely cold dry period spanning ~2000 years occurs directly above the Toba ash. This is consistent with ice core evidence for 18 centuries of extreme cold after Toba during Greenland Ice Stadial event 20 (GI-20s). A sand layer at Pinnacle Point 5-6 rockshelter on the South African coast contains Toba ash. This sand marks an abrupt drop in sea level ~74 ka. It may correlate with sand beds at Blombos and Klasies, and with Malawi and Greenland core evidence for severe climate after Toba. MSA backed blade technologies appear directly above this sand at 72 ka at PP5-6 and at Klasies. Howiesons Poort and similar technologies appeared at this time, suggesting that modern technological and socio-territorial organization strategies may have evolved in response to severe climate during GI-20s. Macroregional social networks may have developed at this time, and may have facilitated modern human dispersals out of Africa.
Cite this Record
Calibrating the Chronology of Late Pleistocene Climate Change and Archaeology with Geochemical Isochrons. Stanley Ambrose. Presented at The 84th Annual Meeting of the Society for American Archaeology, Albuquerque, NM. 2019 ( tDAR id: 451703)
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min long: -18.721; min lat: -35.174 ; max long: 61.699; max lat: 27.059 ;
Abstract Id(s): 25399