库车坳陷北部山前带中生界泥岩元素地球化学特征及其沉积环境意义  

Element geochemical characteristics of Mesozoic mudstones in the northern piedmont zone of the Kuqa depression and their implications to sedimentary environments

作　　者：梁万乐 李贤庆[1,2] 魏强 李谨[3] 孙可欣[1,2] 和钰凯[1,2] 张亚超 Liang Wanle;Li Xianqing;Wei Qiang;Li Jin;Sun Kexin;He Yukai;Zhang Yachao(State Key Laboratory of Coal Resources and Safe Mining,Beijing 100083,China;College of Geoscience and Surveying Engineering,China University of Mining and Technology,Beijing 100083,China;Branch of Natural Gas Geology,PetroChina Research Institute of Petroleum Exploration&Development,Langfang Hebei 065007,China)

机构地区：[1]煤炭资源与安全开采国家重点实验室,北京100083 [2]中国矿业大学(北京)地球科学与测绘工程学院,北京100083 [3]中国石油勘探开发研究院天然气地质研究所,河北廊坊065007

出　　处：《矿业科学学报》2019年第5期375-383,共9页Journal of Mining Science and Technology

基　　金：国家科技重大专项(2016ZX05007-003);中央高校基本科研业务费专项资金(2010YM01)

摘　　要：应用元素地球化学方法,对库车坳陷北部山前带中生界三叠系和侏罗系泥岩的主量元素、微量元素和稀土元素(REE)特征进行了研究,并探讨了其沉积环境意义。结果表明:库车坳陷北部山前带中生界泥岩主要为陆相淡水沉积,稀土元素具有轻稀土富集特征,稀土元素总量反映有机质快速堆积、陆源细碎屑补给速度慢的沉积特征。从三叠纪到侏罗纪古盐度略有上升,古气候以温暖湿润为主,整体处于贫氧—缺氧环境。黄山街组沉积时期温暖湿润的气候与较低的古盐度有利于有机质的形成,贫氧—缺氧环境提供保存条件。至恰克马克组沉积时期古气候开始向干燥炎热转化,且古盐度较高,影响有机质产量,但缺氧环境更有利于其保存。By means of element geochemistry,the characteristics of major elements,trace elements and rare earth elements(REE)for Triassic and Jurassic mudstones from the northern piedmont zone in the Kuqa depression were studied and discussed for the implications fo sedimentry environment.The Mesozoic mudstones from the northern piedmont zone in the Kuqa depression are dominently terrestrial freshwater sedimentary environments.REE are characterized by enrichment of light REE,and reflect the sedimentary characteristics of rapid accumulation of organic matter and slow recharge of terrigenous fine debris.From the Triassic to the Jurassic,the paleosalinity increased slightly while the paleoclimate was mainly humid,and the whole was under dysoxic-anoxic conditions.The warm and humid paleoclimate and lower paleosalinity during the deposition of the Huangshanjie Formation are conducive to the production of organic matter productivity,and the dysoxic-anoxic condition provides preservation conditions.The hot-dry paleoclimate environment began to appear in the period of the Qiakemake Formation,and the higher paleosalinity may promote the formation of organic matter,but the anoxic condition is more conducive to its preservation.

关 键 词：库车坳陷 中生界泥岩 地球化学特征 微量元素 稀土元素 沉积环境意义 

分 类 号：TE122.1[石油与天然气工程—油气勘探]