北山造山带增生造山过程  

Accretionary orogenic processes of the Beishan orogenic belt.

作　　者：宋东方[1] 肖文交[2] 曾浩 毛启贵 敖松坚[1] SONG Dongfang;XIAO Wenjiao;ZENG Hao;MAO Qigui;AO Songjian(State Key Laboratory of Lithospheric and Environmental Coevolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;National Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences,Urumqi 830011,Xinjiang,China)

机构地区：[1]中国科学院地质与地球物理研究所/岩石圈演化与环境演变全国重点实验室,北京100029 [2]中国科学院新疆生态与地理研究所/干旱区生态安全与可持续发展全国重点实验室,新疆乌鲁木齐830011

出　　处：《地质通报》2024年第12期2131-2150,共20页Geological Bulletin of China

基　　金：国家自然科学基金项目《增生造山作用》(批准号:42222210);《大陆演化与季风系统演变》(批准号:42488201);中国科学院青年创新促进会项目(编号:2021062)

摘　　要：北山造山带位于中亚造山带南缘中段,处于东西向构造衔接的关键大地构造位置。近年来,北山造山带构造演化成为研究热点,在基底时代与构造属性、岩浆岩成因、蛇绿岩时代与构造背景、沉积物源与大地构造背景、构造变形样式与时限等方面取得了重要进展。本文以这些新进展为主线,总结北山造山带各构造单元的基本特征,梳理岩浆作用时空格架和蛇绿混杂岩时代,在此基础上探讨北山增生造山过程。北山造山带前寒武纪岩浆记录为零星分布的中元古代(约1.4 Ga)及新元古代(0.9~0.8 Ga)花岗片麻岩,不存在大规模的前寒武纪结晶基底;早古生代—早中生代发育连续的岩浆作用。蛇绿岩时代具有从中部寒武纪—奥陶纪向南北两侧石炭纪—二叠纪变年轻的特点,最终的缝合带位于柳园—后红泉一带,基性岩时代和最年轻的沉积岩基质时代共同限定了最终的增生拼贴时代为中—晚三叠世。北山造山带从中元古代开始位于超大陆外围增生边缘,此后经历了新元古代和古生代的长期增生,在三叠纪完成了最终的增生造山过程并进入陆内演化阶段。增生造山过程中幔源岩浆形成岛弧新生地壳、增生楔和岛弧侧向拼贴增生,对大陆生长具有重要意义。The Beishan orogenic belt is located in the middle of the southern margin of the Central Asian orogenic belt,and is at the key tectonic position of the east−west tectonic connection.In recent years,the tectonic evolution of Beishan has become a research focus,and important progress has been made in the aspects of orogenic basement,magmatism,ophiolitic mélanges,sedimentation,and deformation.This paper focuses on recent advances and summarizes the basic characteristics of each tectonic unit of Beishan,particularly the spatial−temporal distribution of magmatism and ophiolitic mélanges,and discusses the accretionary processes of Beishan.The Precambrian magmatic records are scattered Mesoproterozoic(Ca.1.4 Ga)and Neoproterozoic(Ca.0.9~0.8 Ga)gneissic granitoids,and there is no large−scale Precambrian basement in Beishan.Continuous magmatism developed from Early Paleozoic to Early Mesozoic across Beishan.The ophiolitic mélanges changed from Cambrian–Ordovician in the middle to Carboniferous–Permian in the north and south,and the final suture zone is located in the Liuyuan–Houhongquan area in southern Beishan.The ages of mafic rocks and the youngest sedimentary matrix jointly define the age for terminal accretion as the Middle–Late Triassic.Beishan was located at the margin of supercontinent from the Mesoproterozoic,and then experienced long−term accretion in Neoproterozoic and Paleozoic,and terminated accretionary orogeny and shifted to intracontinental evolution in Triassic.The accretion of mantle−derived arc magmatism and growth of accretionary wedges are of great significance to continental growth during the long−lived accretionary orogenesis.

关 键 词：北山造山带 岩浆作用 蛇绿混杂岩 增生造山 大陆增生 

分 类 号：P54[天文地球—构造地质学] P58[天文地球—地质学]