Guangxi The Liujiang Soil (mouth Sweet) Hole Sites Uranium Series Dating

The origin of modern H. sapiens (MHS) is a major paleanthropology subject of research works and of controversies. Establishing a reliable chronological framework is essential to this study. U-series dating of compact and well crystallized cave calcites, with its fairly high reliability, is commonly used for hominid fossil sites. Taking into account the fact that most of the sites in South China are located in limestone caves where speleothem formations may often be found in stratigraphic context, this chronometer should be promising in addressing the issues of human evolution.Ganqian Cave, located at Tubo District, Liujiang County, Guangxi Zhuang Autonomous Region and unearthed 17 hominid fossil teeth representing at least 13 individuals, is one of the numerous anthropologic cave sites in soudiern China. This paper, based on U-senes dating of speleothem formations and fossil materials, provided the reliable age of this cite, and further discussed the important implications of the results to human evolution research in China.We have carried out Th/U dating on intercalated calcite samples. The results show that the capping flowstone layer is of an age of 94 ka, and the second one 220 ka. The fossil-bearing deposits which are bracketed by the two flowstone layers should be of an age between 94 and 220 ka. 2S(Th/U4U and 227Th/2X"Th dating on two mammal fossil teeth gave age ranging from 85 to 139 ka, which evidence the stratigraphic order between the capping flowstone and the underlying fossil-bearing deposits and support to the age assignment of older than ca.AOO ka to die hominid fossil teeth.The results of our study imply a presence of MHS in southern China much earlier than previously accepted. Parallel studies on Liujiang and Bailiandong hominid sites came out in support of the results given here. These new data indicate that the existing chronological framework for Chinese hominid sites may have been compressed. Early representatives of Chinese MHS in southern China may be contemporaneous with their partners in Africa and in West Asia. Our results are in line with the hypothesis for multi-regional model of MHS. China should not be a retared area in human evolution. A number of the cave sites can be expected to provide important evidence on the emergence, evolution and dispersal of MHS.