Rare earth elemental and Sr isotopic evidence for seawater intrusion event of the Songliao Basin 91 million years ago

作     者：Yu-Ke Liu Hua-jian Wang Jin-You Zhang Zhen-Wu Liu Fa-Zi Chen Xiao-Mei Wang Shui-Chang Zhang He Liu 

作者机构：Research Institute of Petroleum Exploration and DevelopmentBeijing100083China Key Laboratory of Petroleum GeochemistryChina National Petroleum CorporationBeijing100083China Daqing Oil Field CompanyChina National Petroleum CorporationDaqingHeilongjiang163000China School of Ocean SciencesChina University of GeosciencesBejing100083China 

出 版 物：《Petroleum Science》 (石油科学（英文版）)

年 卷 期：2023年第20卷第3期

页      面：1347-1362页

核心收录：

学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：supported by Project of Basic Science Center of National Natural Science Foundation of China(72088101) the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA14010101) National Key Research and Development Program of China(2017YFC0603101) National Natural Science Foundation of China(41872125,42002158) Scientific and Technological Project of RIPED(2021ycq01) the subject development project of RIPED(yjkt2019-3) 

主　　题：Songliao Basin Lacustrine dolostone Seawater intrusion Rare earth elements Strontium isotope 

摘      要：Petrogenesis of lacustrine dolostone is closely related with paleo-lake water *** we report the high spatial-resolution petrographic and geochemical results of a lacustrine dolomite nodule from the Qingshankou Formation,the Songliao *** and elemental signatures confirm the protogenetic origin of this nodule and its effectiveness in recording geochemical characteristics of paleo-lake water during *** low Y/Ho ratios,middle rare earth element(MREE)enrichment and subtle positive Eu anomalies within the nodule indicate a fresh water ***,the Sr isotope values in the core of the nodule(0.7076-0.7080)are close to contemporaneous seawater(0.7074),yet different from the modern river(0.7120)and the host black shale(0.7100).On the premise of excluding the influence of hydrothermal fluids,the significantly low strontium isotope values of the lacustrine dolomite might be caused by seawater interference during *** findings demonstrate that lacustrine dolomite within black shales is not only a faithful tracer of diagenetic water environment,but also a novel and easily identified mineralogical evidence for episodic seawater intrusion event(91 Ma)in the Songliao Basin,which supplements other paleontological and geochemical evidence.