Provenance analysis of Permian sandstones from the Solonker area in central Inner Mongolia, China: Constraints from detrital zircon U-Pb geochronology and whole-rock geochemistry
Provenance analysis of Permian sandstones from the Solonker area in central Inner Mongolia, China: Constraints from detrital zircon U-Pb geochronology and whole-rock geochemistry
复制标题
内蒙古中部索伦克地区二叠系砂岩物源分析：来自碎屑锆石U-Pb年代学和全岩地球化学的制约
DOI：
10.1002/gj.3715
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发表时间：
2020
影响因子：
1.8
通讯作者：
Anderson J. Lawford
中科院分区：
文献类型：
--
作者：
Wu Xiancan;Shi Yuruo;Anderson J. Lawford
以中亚造山带东段构造演化为研究对象，采用全岩地球化学和碎屑锆石U-Pb年代学相结合的方法研究了中亚造山带东段的构造演化。地球化学分析表明，研究区沉积岩套与火山岩套关系密切。7个浙西组碎屑锆石的U-Pb年龄分布在309 ~ 275 Ma和464 ~ 435 Ma之间，其中452和288 Ma为两个主要年龄峰。2634 ~ 543 Ma的碎屑锆石较为稀疏，无明显的年龄峰。结果表明，浙西组沉积发生在中-晚二叠世，主要来源于华北板块前寒武纪基底（1880 Ma和2520 Ma）和华北北缘古生代南造山带（288 Ma和452 Ma）两个时代物源。本文认为，Solonker地区的浙西组形成于早-中二叠世古亚洲洋俯冲构造背景下，可能形成于弧前盆地，而古亚洲洋的最终闭合发生在晚二叠世之后。
We undertook an integrated approach incorporating whole-rock geochemistry and detrital zircon U-Pb geochronology from Permian sedimentary rocks in the Solonker area of central Inner Mongolia, China with the aim of constraining the tectonic evolution of the eastern segment of the Central Asian Orogenic Belt. Geochemical analysis reveals a close relationship between the sedimentary and volcanic rock suites in the study region. Detrital zircons from seven samples collected from the Zhesi Formation yield U-Pb ages that cluster around 309-275 Ma and 464-435 Ma, with two main age peaks of 452 and 288 Ma. However, additional detrital zircons with ages in the range of 2,634-543 Ma are sparse and with no obvious age peaks. The results suggest that the deposition of the Zhesi Formation occurred from the Middle to the Late Permian and from two major age provenances: the Precambrian basement of the North China Plate (1,880 Ma and 2,520 Ma) and the Paleozoic Southern orogenic belt along the northern margin of North China (288 Ma and 452 Ma). In this contribution, we suggest that the Zhesi Formation in the Solonker area formed in response to the Early to Middle Permian subduction tectonic setting of the Paleo-Asian Ocean (PAO), probably formed in a forearc basin and that the final closure of the PAO occurred after the Late Permian.