鲁西南单县盆地钻孔记录的古近纪环境变化  

Paleogene Environmental Changes Recorded by the Borehole in the Shanxian Basin,Southwestern Shandong

作　　者：路淑毅 杨斌 李胜荣[1] 宋香锁 杜圣贤 高建飞[6] 张尚坤 李明慧[2] 张伟林[2] LU ShuYi;YANG Bin;LI ShengRong;SONG XiangSuo;DU ShengXian;GAO JianFei;ZHANG ShangKun;LI MingHui;ZHANG WeiLin(School of Earth Science and Resources,China University of Geosciences(Beijing),Beijing 100083,China;Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China;Shandong Institute of Geological Sciences,Jinan 250013,China;Key Laboratory of Gold Mineralization Processes and Resource Utilization,Ministry of Natural and Resources,Jinan 250013,China;Shandong Key Laboratory of Mineralization Processes and Resource Utilization in Metallic Minerals,Jinan 250013,China;Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China)

机构地区：[1]中国地质大学(北京)地球科学与资源学院,北京100083 [2]中国科学院青藏高原研究所,北京100101 [3]山东省地质科学研究院,济南250013 [4]自然资源部金矿成矿过程与资源利用重点实验室,济南250013 [5]山东省金属矿产成矿地质过程与综合利用重点实验室,济南250013 [6]中国地质科学院矿产资源研究所,北京100037

出　　处：《沉积学报》2023年第2期498-510,共13页Acta Sedimentologica Sinica

基　　金：中国科学院战略性先导科技专项(XDA20070201,XDA20070101);国家重点研发计划(2017YFC0602803);第二次青藏高原科学考察项目(2019QZKK0202,2019QZXX0707)。

摘　　要：鲁西南地区的单县盆地盐矿是新发现的小陆块盆地形成的大型盐类矿床,成矿时代为古近纪(主要是始新世中晚期至渐新世)。基于单县盆地YZK-3钻孔(521.7 m)元素和碳氧同位素的分析,探讨单县盆地在古近纪时期的古环境演化特征。研究表明:1)单县盆地YZK-3孔沉积物水溶元素和酸溶元素及比值的变化反映了湖泊的咸化和淡化过程;2)受热液补给和成岩作用影响,碳酸盐δ18O和δ13C的相关性不适合论湖泊的封闭与开放状态,但变化趋势仍具有古环境意义;3)始新世—渐新世,单县盆地古湖泊经历了淡水湖—咸水湖—盐湖—咸水湖—淡水湖的演化过程,其干旱化趋势明显。全球气候变化是成盐作用的主要驱动机制。The salt deposit in the Shanxian Basin in southwestern Shandong is a large-scale salt deposit formed in a typical small continental basin.This salt deposit developed during the Paleogene period(mainly the Middle and Late Eocene-Oligocene).Based on the elements and carbon and oxygen isotopes(δ18O andδ13C)in borehole YZK-3(521.7 m)in the Shanxian Basin,this study tried to reconstruct the paleoenvironmental evolution characteristics of the Shanxian Basin.The main conclusions are as follows:(1)The changes of water soluble and acid soluble element contents and ratios are basically consistent with the lake status as freshwater or salt water.(2)Due to hydrothermal in⁃flow and diagenesis,the correlation betweenδ18O andδ13C of carbonate minerals is not useful in discussing the clo⁃sure and open state of the lake.However,the trend ofδ18O andδ13C still could be used to talk about the paleoenvironmental changes.(3)From the Eocene to the Oligocene,the ancient lakes of the Shanxian Basin experienced the evolution process of freshwater lake⁃brackish water lake⁃salt lake⁃brackish water lake⁃freshwater lake.Global cli⁃mate change is the main driving factor for the evaporate deposit.

关 键 词：碳氧同位素 元素 古环境 古近纪 单县盆地 

分 类 号：P531[天文地球—古生物学与地层学]