古人类遗址湖北郧西黄龙洞的铀系年代

湖北郧西黄龙洞为近年来发现的晚期智人遗址。本文报道该地点具明确层位意义的洞穴次生碳酸盐岩和骨化石样铀系测年的结果。含文化堆积下伏一局部钙板的年代为约100ka BP, 其中部偏上一局部钙板为约77ka BP, 表层钙板形成于27—57ka BP间。人类化石和石制品出土于文化堆积的底部, 其年代应在57—100ka BP, 并很可能在77—100ka BP间。与人牙化石同层的四枚犀牛牙化石在35—72ka BP间, 与基于次生碳酸盐岩的年代框架没有冲突。本文结果为中国现代人类的早期出现和距今40—100ka BP间有人类活动提供了有力证据。

U-series Dating of Huanglong Cave, a Paleolithic Site at Yunxi, Hubei Province

Huanglong Cave is located at Yunxi County, Hubei Province in central China. Three excavations between 2004 and 2006 lead to the discovery of seven human teeth,dozens of stone and bone artifacts and other evidence of hominin activities. The mammalian fossils represent the Middle-Late Pleistocene "Ailuropoda-Stegodon" fauna commonly found in southern China. Judging by morphological and metric features, the human teeth should be classified as modern Homo sapiens.The deposits inside the cave are divided into five layers. All of the hominin teeth and artifacts, and most of the mammalian fossils were unearthed from the deposits of Layer 3 at Region 1 located ca.100m from the cave entrance and intercalated by flowstone layers, from which four relatively pure and dense calcite samples were taken. Here we report the results of U-series dating of these samples with conventional α spectrometry. A small stalagmite that developed on a flowstone layer beneath Layer 3 gives an age of ~100ka BP. A thin flowstone layer intercalated in the upper part of the deposits dates to ~77ka BP. Two calcite samples taken from the capping flowstone indicate its formation between 57—27ka BP. This paper reports also the U-series dates on four rhinoceros teeth that fall within the range 35—72ka BP, which is consistent with dates on speleothem samples. The excavators claimed that the deposits inside the cave exhibit a relatively simple and consistent stratigraphic sequence. If so, the human teeth and stone artifacts, recovered from the lowest section of Layer 3, should be bracketed in the range of 100 and 77ka BP. This conclusion is in support of a much earlier presence of modern H.sapiens in Asia than previously thought, in particular before the Younger Toba eruption at 74ka BP. Even considering the fact that the samples for dating were not collected during the excavations and that generally the stratigraphy of cave deposits tends to be quite complicated, the human fossils from Huanglong Cave should be emplaced before the formation of capping flowstone at 57ka BP, much older than the fossils from Tianyuan Cave at Zhoukoudian, which is widely accepted as the oldest representative of modern H.sapiens in China.The results of this paper indicate that humans lived in China in the so-called "temporal gap" of 100—40ka BP.