Ce Anomalies of the Yangtze Region,South China,through the Ordovician and Silurian Transition

作     者：严德天 张丽琴 李双建 YAN DETAIN KEY LABORATORY OF TECTONICS AND PETROLEUM RESOURCES OF MINISTRY OF EDUCATION;CHINA UNIVERSITY OF GEOSCIENCES;WUHAN;CHINA;INSTITUTE OF GEOLOGY AND GEOPHYSICS;CHINESE ACADEMY OF SCIENCES;BEIJING;CHINA ZHANG LIQIN SCHOOL OF GEODESY AND GEOMATICS;WUHAN UNIVERSITY;WUHAN;KEY LABORATORY OF GEOSPACE ENVIRONMENT & GEODESY OF MINISTRY OF EDUCATION;CHINA LI SHUANGJIAN PETROLEUM EXPLORATION AND PRODUCTION INSTITUTE OF SINOPEC;BEIJING ...

作者机构：Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education China University of GeosciencesWuhan Institute of Geology and Geophysics Chinese Academy of Sciences School of Geodesy and Geomatics Wuhan University Key Laboratory of Geospace Environment & Geodesy of Ministry of Education Wuhan University Petroleum Exploration and Production Institute of SINOPEC 

出 版 物：《Journal of Earth Science》 (地球科学学刊（英文版）)

年 卷 期：2009年第20卷第6期

页      面：941-948页

核心收录：

学科分类：070903[理学-古生物学与地层学(含：古人类学)] 081803[工学-地质工程] 0709[理学-地质学] 07[理学] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：This study was supported by the National Natural ScienceFoundation of China (No. 40903032) the Research Foundationfor Outstanding Young Teachers,China University of Geo-sciences (Wuhan) Key Laboratory of Biogeology and En-vironmental Geology of Ministry of Education,China University of Geosciences (No.BGEGF200810) 

主　　题：Ce anomaly redox mass extinction Ordovician/Silurian boundary Yangtze platform. 

摘      要：Systematic Ce anomalies for whole-rock have been obtained from the shale-dominated, continuous, and pelagic sedimentary sequences spanning the Ordovician/Silurian （O/S） boundary at the Tieshui （铁水） of Xiushan （秀山）, Chongqing （重庆）, South China. Ce anomalies across the O/S boundary are recognized in three intervals, Wufeng （五峰）, Guanyinqiao （观音桥） and Longmaxi （龙马溪）. The calculated Ce/Ce＊ values of Wufeng Formation range from 0.84 to 0.96 （avg. 0.90）. In the Guanyinqiao Formation, the values of calculated Ce/Ce＊ range from 0.73 to 0.85 （avg. 0.79）. The Ce/Ce＊ values of uppermost Longmaxi Formation range from 0.87 to 0.96 （avg. 0.91）. All along the section, the magnitude of the Ce anomaly is always negative, but is more significant in the Guanyinqiao Formation. The relatively higher Ce/Ce＊ values in the Wufeng and Longmaxi shales are likely to be due to the sediments deposited under rather reducing conditions. The Ce anomaly apparently does play some regular roles in the anoxic events that accompany prominent mass extinctions, and this work provides new data of critical importance for constraining models on the end-Ordovician anoxic events and mass extinctions.