关键词: 三峡库区;二级埋藏阶地;东方剑齿象;晚更新世

Abstract: Three pieces of molar of Stegodon orientalis were unearthed in a gravel layer of second terrace of the Yangtze River, near the village of Pujiacun, Wanxian county, Chongqi. The deposits of second terrace are composed of three layers, namely a clay layer on the top, a thin calcified layer in the middle and a gravel layer at the bottom. The molar of Stegodon orientalis from the gravel layer is dated by U-series method back to 64 000±5 000 years BP. In addition, some ebony materials obtained from the clay layer are dated by Carbon 14 method back to 7 930±90 years BP. Through analyzing the relationships of these layers, we draw a conclusion that the sandy gravel layer is actually the second terrace deposit covered by the clay deposit of the first terrace. In addition, the gravel layer partially cemented by calcium carbonate shows that there existed a period of cold and dry climate between the Late Pleistocene and the Early Holocene. These discoveries provide important information for the study of the formation and age of the lower terrace, the effect of the Neotectonic Movements, the Paleoclimate, etc.

Key words: Three Gorges region; Buried second terrace; Stegodon orientalils; Late Pleistocene