文献类型：期刊文献

中文题名：中甸三叠纪弧后前陆盆地中的碎屑锆石:亲扬子地块群的原特提斯岩浆记录

英文题名：Detrital zircon age-spectra of a Triassic backarc foreland basin in Zhongdian area:Proto-Tetheyan magmatic record of Yangtze-affinited blocks in SE Tibet

作者：信迪 杨天南 薛传东 姜丽莉 向坤

第一作者：信迪

机构：[1]中国地质科学院地质研究所,北京100037;[2]中国地质科学院,深地科学与探测技术实验室,北京100037;[3]昆明理工大学地球科学系,昆明650093;[4]中国地质调查局成都地质调查中心,成都611230;[5]贵州理工学院资源与环境工程学院,贵阳550003

第一机构：中国地质科学院地质研究所,北京100037

年份：2024

卷号：40

期号：12

起止页码：3817-3829

中文期刊名：岩石学报

外文期刊名：Acta Petrologica Sinica

收录：CSTPCD;;Scopus;北大核心:【北大核心2023】；CSCD:【CSCD2023_2024】；

基金：国家自然科学基金项目(42202250);中国地质科学院地质研究所基本科研业务费项目(J2318)联合资助。

语种：中文

中文关键词：原特提斯;中咱地块;弧后前陆盆地;碎屑锆石;大扬子地块

外文关键词：Proto-Tethys;Zhongza Block;Back-arc foreland basin;Detrital zircon;Greater Yangtze Block

摘要：作为东特提斯造山系的主体,我国的青藏高原及其周缘地区保留了最为完整的特提斯演化相关地质记录,但原特提斯阶段的构造演化历史尚未取得共识。三江造山带位于巨型阿尔卑斯-喜马拉雅造山系的东段。晚古生代-早中生代古特提斯构造运动、中-晚中生代新特提斯构造运动和新生代以来的陆-陆碰撞构造运动的多次叠加和改造致使造山带内部分地块的原特提斯演化历史难以恢复,阻碍了古地理、古构造格局的合理重建。针对东羌塘地块和中咱地块新元古代至古生代时期的构造演化研究程度较低,相关数据报道较少,本文通过对横穿中咱地块剖面的综合研究,认为中甸东侧发育早三叠世小型弧后前陆盆地。该弧后前陆盆地充填物主要为下三叠统碎屑岩,长石岩屑砂岩的碎屑锆石中岩浆锆石的表面年龄峰值区间主要为1900~1800Ma、970~940Ma、510~410Ma、390~320Ma和301~240Ma。中咱地块古生界两个年龄峰值(390~320Ma和301~240Ma)与扬子地块古生界碎屑锆石年龄谱高度相似,表明中咱地块的前寒武纪基底与扬子地块相连。东羌塘、中咱、兰坪(印支)地块与扬子地块一起组成大扬子地块,其西南缘、东南缘发育早古生代岩浆岩带。在印度-欧亚大陆碰撞之前,这一岩浆岩带呈近东西向位于大扬子地块南缘,为其内部古生界的沉积物源区。
As the main body of the East Tethys orogenic system,the Tibetan Plateau and its peripheral areas in China retain the most complete geological records related to the Tethys evolution.However,the tectonic evolution history of the Proto-Tethys stage in Tibetan Plateau has not yet reached a consensus.The Sanjiang Orogen is located in the eastern part of the Alpine-Himalayan orogenic system.The multistage tectonism,including the Paleo-Tethys tectonic movement in Late Paleozoic-Early Mesozoic,the Neo-Tethys tectonic movements in Middle-Late Mesozoic,and the continent-continent collisional tectonic movements since the Cenozoic era,have made it difficult to recover the Proto-Tethys evolutionary history and reconstruct the palaeogeographic and palaeotectonic patterns of Sanjiang Orogen.It has been poorly studied that the tectonic evolutions of East Qiangtang Block and Zhongza Block in Neoproterozoic and Paleozoic,because the relevant data are rarely reported.In this paper,through a comprehensive traverse study of the east of Zhongdian,we found that a small Late Permian-Early Triassic back-arc foreland basin was developed on the Zhongza Block.The sediment fillings of back-arc foreland basin is mainly composed of Upper Permian-Lower Triassic clastic rocks.The peak surface ages of magmatic zircons in the detrital zircons ages from the feldspathic lithic sandstone have five prominent peaks at 1900~1800Ma,970~940Ma,510~410Ma,390~320Ma and 301~240Ma.The two Paleozoic peaks(390~320Ma and 301~240Ma)of Zhongza Block are highly comparable to the Paleozoic detrital zircon age spectra of the Yangtze Block,indicating that the Precambrian basement of the Zhongza Block is connected to the Yangtze Block.The East Qiangtang,Zhongza and Lanping(Indochina)blocks together with the Yangtze Block form the Greater Yangtze Block,and the Early Paleozoic Belt magmatism was developed in the southwestern and southeastern edges of the block.Prior to the India-Eurasia collision,this magmatic belt was orientated nearly east-west at the southern edge of the Greater Yangtze Block,which was the provenance of Paleozoic sediments within the Yangtze Block.