塔里木盆地东北缘下寒武统泥页岩古气候与物源背景研究  

Paleoclimate and Provenance Background of Lower Cambrian Mudstone in the Northeastern Margin of Tarim Basin

作　　者：谢巍 李一凡[1,2] 刘旺威[1,2,3] XIE Wei;LI YiFan;LIU WangWei(School of Energy Resources,China University of Geosciences(Beijing),Beijing 100083,China;Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Enrichment Mechanism,Ministry of Education,China University of Geosciences(Beijing),Beijing 100083,China;Wuxi Research Institute of Petroleum Geology,Petroleum Exploration and Production Research Institute,SINOPEC,Wuxi,Jiangsu 214126,China)

机构地区：[1]中国地质大学(北京)能源学院,北京100083 [2]教育部海相储层演化与油气富集机理重点实验室,中国地质大学(北京),北京100083 [3]中国石化石油勘探开发研究院无锡石油地质研究所,江苏无锡214126

出　　处：《沉积学报》2023年第4期1240-1256,共17页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(U19B6003-01-02,41802155)。

摘　　要：通过对库鲁克塔格地区下寒武统泥页岩的主微量元素数据进行地球化学分析,探讨了早寒武世塔里木盆地东北缘的古气候演化特征、物源输入背景、泥页岩成因模式。CIA值及SiO_(2)-(Al_(2)O_(3)+K_(2)O+Na_(2)O)图解表明,研究区古气候由埃迪卡拉纪进入寒武纪变暖,进入寒武纪后再次变得寒冷干旱。Ce/Ce^(*)值和(La/Ce)N值表明西山布拉克组沉积背景为洋中脊附近的深海洋盆,其上覆的西大山组和下伏的汉格尔乔克组为稳定的大陆边缘背景。La-Th-Sc图解表明恰克马克铁什Ⅰ号剖面泥页岩形成时构造环境为被动大陆边缘,恰克马克铁什Ⅱ号剖面构造环境变化较大。Th-Sc、Th/Sc-La/Sc图解及公式化判别函数表明,恰克马克铁什Ⅰ号剖面母岩性质为中性—中酸性岩浆岩,其物源可能来自于中央隆起带前寒武系的中酸性喷出岩、花岗闪长岩、橄榄石花岗岩等,恰克马克铁什Ⅱ号剖面母岩性质为基性—中酸性岩浆岩,其铁镁质组分明显增加,除中央隆起带物源的输入外,可能受到海底铁镁质热液喷出的影响。Based on the geochemical analysis of the Lower Cambrian mudstone in the Kuluketage area,the paleoclimate,provenance,and formation of mudstone in the Early Cambrian are discussed.In the study area,the CIA value and SiO_(2)-(Al_(2)O_(3)+K_(2)O+Na_(2)O)diagram show that the paleoclimate in the Early Cambrian was warmer than in the Ediacaran,and became cold and dry again in the Cambrian.The Ce/Ce^(*)and(La/Ce)N values indicate that the Xishanbulake Formation was deposited in a submarine basin near a mid ocean ridge(MOR),and the overlying Xidashan and underlying Hangeerqiaoke Formations are deposited in a stable continental margin.The La-Th-Sc diagram shows that the tectonic setting of the formation in section QKMK-Ⅰ was a passive continental margin,while section QKMK-Ⅱ.Th-Sc and Th/Sc-La/Sc diagrams and discriminant functions indicate that the parent rock of section QKMK-Ⅰ is a neutral to intermediate-acid igneous rock,and its provenance may be intermediate-acid rock of the Precambrian in the central uplift zone.The parent rock of section QKMK-Ⅱ is a mafic to intermediate-acidic igneous rock,and its mafic components obviously increased.Except for the central uplift zone provenance,it may be affected by the effusion of mafic hydrothermal fluids from the seabed.

关 键 词：寒武系 库鲁克塔格 主量元素 泥页岩 古气候 微量元素 

分 类 号：P512.2[天文地球—地质学]