扬子地台震旦纪海水碳同位素的变化

扬子地台震旦纪海水碳同位素的变化

王宗哲杨杰东孙卫国

中国科学院南京地质古生物研究所

收稿日期:1996-03-20 修回日期:1996-03-20 出版日期:1996-03-20 发布日期:1996-03-20

CARBON ISOTOPE RECORD OF SINIAN SEAWATER IN YANGTZE PLATRORM

Wang Zhongzhe1, Yang Jiedong2, Sun Weiguo1

1. Nanjing Institute of Geology and Palaeontology, Academia Sinica, Nanjing 210008; 2. Center of Modern Analysis, Nanjing University, Nanjing 210093

Received:1996-03-20 Revised:1996-03-20 Online:1996-03-20 Published:1996-03-20

摘要/Abstract

摘要： 本文测定了湖北宜昌三峡剖面震旦系海相碳酸盐岩样品的碳同位素组成。研究表明：震旦纪扬子区海水的δ＾１３Ｃ值显示出大幅度变化，南沱冰期δ＾１３Ｃ为低值（－４‰）；陡山沱早期δ＾１３Ｃ值迅速上升，达到５－６‰，陡山沱期δ＾１３Ｃ值一般在０－５‰之间；灯影期δ＾１３Ｃ值较平稳，一般在２．０－３．４％之间，导致震旦经水δ＾１３Ｃ值大幅度变化的原因主要是由于以疑在和近岸为藻类等光合作用的海洋植物群体为主体的大量生物的繁盛、全球海洋沉积速率的迅速上升，以及海洋深部水柱中缺氧层的存在。

Abstract: Carbon isotopic compositions of Sinian marine carbonates from the Yangtze Gorges sections near Yichang, South China, have been investigated. The δ13C values showed large variation during the Sinian. The marine carbonates have typical lowδ13C values of about -4‰ in the Nantuo Period. At the beginning of the Doushantuo Period the values increased rapidly, and reached +5～+6‰ in the early and middle time of the Doushantuo Period. The mass of 13Cvalues remained stably positive, ranging generally between +2.0‰ and +3.4‰. The large varations of carbon isotopic compositions of Sinian seawater are mainly due to violent growth and wide extending of acritarch and algae, rapid increasing of global sedimentary rate, and development of “oceanic anoxic event”, i.e. the existence of anoxic layer in deep seawater during that time.

王宗哲杨杰东孙卫国. 扬子地台震旦纪海水碳同位素的变化[J]. J4.

Wang Zhongzhe1, Yang Jiedong2, Sun Weiguo1. CARBON ISOTOPE RECORD OF SINIAN SEAWATER IN YANGTZE PLATRORM[J]. J4.