雪峰山早中生代构造演化：构造学和年代学分析  

Tectonic evolution of the Early Mesozoic Xuefengshan belt: Insights from structural analysis and geochronological constraints

作　　者：褚杨[1,2,3] 林伟[1] Michel Faure 王清晨[1] 

机构地区：[1]中国科学院地质与地球物理研究所岩石圈演化国家重点实验室,北京100029 [2]Institue des Sciences de la Terre d'Orleans,Campus Geosciences,Universite d'Orleans,1A Rue de la Ferollerie,45071 Orleans Cedex 2,France [3]中国科学院研究生院,北京100049

出　　处：《地质科学》2011年第1期146-160,共15页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家重点基础研究发展计划“973”项目(编号:2005CB422101);中国科学院知识创新工程重大项目(编号:KZCX1-YW-15-1)资助

摘　　要：雪峰山主体地处湖南省境内,位于华南板块的中心区域,是一条典型的陆内造山带。通过详细的野外地质观察,我们将其分为3个构造单元:西部外区,主要以大型箱状褶皱为主;中部区,与西部区以主逆冲断层相分隔,劈理发育呈扇状,是雪峰山构造带的核心区域,也是变质级别最深、变形最强的区域;东部区,变形集中在脆韧性区域之上,以极性北西构造为主,并有反向构造发育。研究区经历了3期构造变形:D_1为上部指向北西的韧性剪切,广泛发育于整个区域;D_2代表了一期反向褶皱—逆冲构造事件;D_3则以水平挤压为主,形成了直立的褶皱、劈理和线理。雪峰山的构造演化表明华南板块东南缘古太平洋板块向北西方向的俯冲可能引发了早中生代的陆内俯冲造山过程。In the center of the South China Block,in Hunan Province,the Xuefengshan Belt provides a well-exposed example of intracontinentat orogens. Detail field observations indicate that the Xuefengshan Belt can be divided into：（ 1 ）the Western Outer Zone, characterized by km-scale box-fold structure; （2）the Central Xuefengshan Zone, where the dip of the cleavage surface exhibits a fan-like pattern, separated from the Western Outer Zone by the Xuefengshan Main Thrust,the most deformed and metamorphosed region in this belt; （3）and the Eastern Zone, deformed mainly in the brittle-ductile level,characterized by top-to-the-NW structures and also some back-folding structures. The Xuefengshan Belt results of polyphase deformation： D~, characterized by a widespread top-to-the-NW ductile shearing. D2 corresponds to a SE-directed back thrusting and folding event. D3 consists of upright folds with vertical cleavage and lineation. The tectonic evolution of the Early Mesozoic Xuefengshan Belt is possibly originated by the continental subduction in response to the northwest directed subduetion of the Pacific plate.

关 键 词：华南板块 雪峰山 早中生代 多期构造变形 陆内造山 

分 类 号：P542[天文地球—构造地质学]