The Benxi Miaohou Ruins Uranium Series Dating

For about 20 years,there has been an intense debate over the origin of anatomically modern Homo sapiens between exponents of two competing hypotheses,"multiregional origins" and "recent out of Africa".The phylogenetic relationship between Homo erectus and archaic Homo sapiens in East Asia impacts directly on the hotly debated issues.According to the previously accepted chronology,the erectus-sapiens interface in China occurred somewhere around 200 ka, far too late compared with the same transition event in Africa which is believed to take place ca. 600 ka.The Miaohoushan site,with the recovery of 3 hominid fossils,76 stone artifacts and a faunal assemblage of 72 mammalian species,is known for marking the northernmost human presence in Middle Pleistocene China.This paper presents ²³⁰Th/²³⁴U dates on four calcite and two fossil samples from the hominid fossil-bearing 5^thand 6^thdepositional layers of the site.The flowstone intercalated in 5^thlayer yields an age of 526±30 ka,while three speleothem horizons of the 6^th layer give ages of 276_-38⁺⁶⁰,＞535 and 346_-61⁺¹⁶⁰ka respectively.Based on these results we propose that the topmost section of the 6^thlayer should be no less than 200 ka,and the middle pan of the 5^thlayer older than 500 ka.The results here presented,much older than the previous temporal frame based on the U-series dates on fossil bones,are in support of the proposition for a much earlier Homo erectus-archaic Homo sapiens interface in China.The conclusion is consistent with the chronology of several hominid sites,including Zhoukoudian Localities 1,4 and 15 and Chaoxian hominid site that has been studied with the U-series dating intercalated speleothem formations,being in line with the observation that the existing chronological framework for Chinese Middle sites may have been compressed as a whole. The erectus-sapiens interface in China may be not far from that the same event took place in Africa.If being proved further,our results would impact profoundly on the models of human evolution in East Asia.