盘县大洞古人类遗址的地层和古气候研究

STRATIGRAPHIC AND PALEOENVIRONMENTAL STUDIES AT THE DADONG CAVE,PANXIAN

贵州盘县大洞的堆积物 ,自上而下可以分为 3层。大洞主体堆积物为角砾堆积 ,来源于洞顶灰岩的崩塌 ,另外有人类遗物以及洞外片流作用带入的泥砂。人类化石、旧石器和哺乳动物化石主要分布在第 2层角砾堆积中。堆积物在洞厅各部位均有相应分布 ,属同一沉积序列。已知的早期人类活动时间大约从2 60ka .B .P .开始 ,到 142ka .B .P .前后结束 ,对应于深海氧同位素的第 6、7阶段。角砾层下段 ,发育一套遭强烈溶蚀和风化的堆积物 ,地球化学分析结果显示其湿热的沉积环境 ,时间大约在 2 60— 180kaB .P .期间 ,对应于深海氧同位素第 7阶段 ;大洞堆积物在气候变化周期上与黄土。

Deposits of the excavated area at the Dadong Cave in Panxian County,Guizhou Province,can be divided into three stratigraphic units,distributed in all parts of the main hall.Human fossils,stone artifacts and mammalian fauna were unearthed mainly from the second stratum,a breccia deposit.Angular rocks resulted from roof-fall and boulders are the main source of the deposits,filled with clay and sands,. The current U-series and ESR dating results indicate that early human activities in the cave began around 260 ka and ended at approximately 42 ka,which corresponds to Oxygen Isotope Stage 6 and 7. Strongly weathered dark deposits were detected from the lower breccia,suggesting a warm climatic period from 260 to 180 ka and corresponding to Oxygen Isotope Stage 7. The periodic climatic changes derived from the Dadong deposits can be compared with sequences of loess and glacia/interglacial sequence of the Qinghai-Tibet Plateau.