华南板块东南部南华纪‒震旦纪沉积地层 区域对比、物源特征及构造演化  

Nanhuan-Sinian Sedimentary Strata Correlation and Its Provenance Feature in Southeastern Part of South China Block:Implications for Tectonic Evolution

作　　者：宋芳 何垚砚 牛志军 杨文强 王志宏 Song Fang;He Yaoyan;Niu Zhijun;Yang Wenqiang;Wang Zhihong(Hubei Key Laboratory of Paleontology and Geological Environment Evolution,Wuhan 430205,China;Wuhan Center,China Geological Survey(Geosciences Innovation Center of Central South China),Wuhan 430205,China)

机构地区：[1]古生物与地质环境演化湖北省重点实验室,湖北武汉430205 [2]中国地质调查局武汉地质调查中心(中南地质科技创新中心),湖北武汉430205

出　　处：《地球科学》2024年第9期3411-3427,共17页Earth Science

基　　金：中国地质调查局地质调查项目(Nos.DD20240038,DD20243437,DD20243480,DD20230226);国家自然科学金面上项目(Nos.U2244212,41772019);古生物与地质环境演化湖北省重点实验室开放基金项目(No.PEL⁃202106).

摘　　要：华南板块东南部南华纪‒震旦纪的沉积大地构造背景等问题尚存在争议,本文以研究区内北东‒南西向分布、砂岩‒板岩夹砾岩为主要特征的碎屑岩地层为突破口,开展区域地层对比及物源示踪,进而对该地区沉积大地构造背景进行约束.对闽西南、赣中、湘东南以及桂北4个地区的代表性南华纪‒震旦纪沉积地层剖面开展了岩性对比和碎屑锆石定年工作,结果显示:研究区内不同地区南华纪‒震旦纪碎屑岩地层的岩石组合及沉积序列特征相似,以900~1100 Ma年龄峰值为特征的物源从南华纪早期至震旦纪持续地从南东向北西推进.同时,本文从岩性和物源两个方面定义了“华夏型陆源碎屑地层”.研究结果对政和‒大埔断裂带以西的扬子陆块和华夏地块之间在南华纪‒震旦纪存在宽阔大洋的分隔提出了质疑.The sedimentary tectonic background of the southeastern part of South China Block(SCB)remains controversial.This study focuses on the set of NE-SW stretching clastic sedimentary with alternating lithology of sand and slate with regional gravel interbeds,conducting the sedimentary strata correlation and detrital zircon U-Pb ages in order to constrain the sedimentary tectonic background.Four Nanhuan⁃Sinian sedimentary strata sections have been studied and the results show that Nanhuan⁃Sinian sedimentary of the southeastern part of SCB could be well correlated and provenance with detrital zircon age peak of 900-1100 Ma migrated from southeast to northwest from the Early Nanhuan to Sinian.“Cathaysia-derived Clastic Strata”are identified according to the lithology and provenance features.The results challenge the opinions that there had been a wide ocean between the blocks of Yangtze and Cathaysia during Nanhuan⁃Sinian to the west of Zhenghe-Dapu Fault in study area.

关 键 词：华南板块 南华纪 震旦纪 地层对比 碎屑锆石 地层学 沉积学. 

分 类 号：P535[天文地球—古生物学与地层学]