Geochemical Characteristics of the Peleoenvironment of Sediment of the First Terrace of the Three Gorge of the Changjiang——A Case Study for the Youxing Profile of Jiangjin
详细信息
- 责任者：Xia Kiasheng (School of Geography Science ; Southwest University ; Chongqing 400715 ; China) ; Xie Shengyou
- 刊名：Journal of Mountain Science
- 出版年：2010
- 卷期：28(5)
- 关键词：放射性碳计时 ; 河流阶地 ; 晚更新世 ; 长江三峡
- 页码：p.519-525
- 图表：illus., 3 tables, 28 refs.
- 分类号：1400
- issnNo：ISSN1008-2786
- isbnNo：CN51-1516/P
摘要
The 14 C age dating method was applied to study the deposited age of the the first terrace of the Three Gorge of the Changjiang in Youxi profile,Jiangjin.The geochemical characteristics of oxides such as MgO,CaO,Fe2O3,FeO,Fe2O3/FeO were analyzed.It was found that the Fe2O3 and the Fe2O3/FeO ratio are high in the lower incompact gravel bed,whereas FeO、CaO、MgO are lower.The characteristics of the oxides in the diagenetic conglomerate are opposite.The 14 C age dating indicated that the deposited age of the first terrace was between 13.4ka.BP and 40.0ka BP.The geochemical results shown that the Jiangbei conglomerate might be deposited under a dry and cold climate during the last Glacial age in late Pleistocene,.and these geochemical characteristics recorded in cyclic sedimentations of this area reflected the changes of alluvial system dynamics,and implicated warm/wet-cold/dry cyclic changes in late Pleistocene.