塔里木盆地塔中志留系柯坪塔格组物源示踪:碎屑锆石U-Pb年代学证据  

Provenance of Silurian Kepingtage Formation in Tazhong Area, Tarim Basin:Evidence from Detrital Zircon U-Pb Geochronology

作　　者：李祥权[1,2] 丁洪坤[3] 彭鹏[3] 吴梅莲[3] 钟楚红 柴雄[3] 刘国威[3] 彭丽[3] Li Xiangquan;Ding Hongkun;Peng Peng;Wu Meilian;Zhong Chuhong;Chai Xiong;Liu Guowei;Peng Li(Hubei Key Laboratory of Marine Geological Resources,China University of Geosciences,Wuhan 430074,China;Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education,China University of Geosciences,Wuhan 430074,China;PetroChina Tarim Oilfield Company,Kuerle 841000,China)

机构地区：[1]中国地质大学海洋地质资源湖北省重点实验室,湖北武汉430074 [2]中国地质大学构造与油气资源教育部重点实验室,湖北武汉430074 [3]中国石油塔里木油田分公司,新疆库尔勒841000

出　　处：《地球科学》2021年第8期2819-2831,共13页Earth Science

基　　金：国家自然科学基金项目(No.41672110)。

摘　　要：目前对塔中志留系物源的认识仍存在不确定性.利用LA-ICP-MS分析技术对塔里木盆地塔中地区志留系柯坪塔格组2件样品开展碎屑锆石U-Pb年代学研究.结果表明塔中志留系碎屑锆石主要为岩浆结晶成因,锆石年龄主要分布在早古生代460~490 Ma、新元古代760~1 000 Ma、古元古代1 600~2 200 Ma及新太古代晚期-古元古代早期2 400~2 600 Ma四个时期,其中新元古代760~1 000 Ma碎屑锆石年龄占绝对优势(56.8%),峰值~850 Ma.结合志留纪时期塔里木板块南北缘的板块动力学背景,通过盆内构造演化及地貌特征的分析以及和潜在源区锆石年龄的详细对比,确定塔中志留系碎屑锆石主要来源于塔里木盆地西南缘的铁克里克隆起构造带.There is still uncertainty in the understanding of the source of the Silurian sedimentation in Tazhong area of Tarim Basin. Using LA-ICP-MS analysis technology, two samples of the Kepingtage Formation in Tazhong area were collected for detrital zircon U-Pb chronology. The results show that the zircons are mainly of magmatic crystallization origin and their ages are mainly distributed in four periods: Early Paleozoic 460-490 Ma, Neoproterozoic 760-1 000 Ma, Paleoproterozoic 1 600-2 200 Ma, and Late Neoarchaean-Early Paleoproterozoic 2 400-2 600 Ma. The Neoproterozoic 760-1 000 Ma detrital zircon ages take the largest proportion(56.8%), with a ~850 Ma single peak. Based on the plate dynamics background of the northern and southern margins of the Tarim plate during the Silurian Period, the analysis of tectonic evolution and geomorphologic features within the basin, as well as the detailed comparison of zircon ages with the potential provenance area, it is proposed that the Tazhong Silurian detrital zircons were mainly sourced from the Tiekelike uplift in the southwest margin of Tarim Basin.

关 键 词：物源 碎屑锆石 U-PB年代学 柯坪塔格组 志留系 塔中地区 塔里木盆地 

分 类 号：P597[天文地球—地球化学]