初论陆-陆碰撞与成矿作用——以青藏高原造山带为例  

Continental Collision and Related Metallogeny: A Case Study of Mineralization in Tibetan Orogen

作　　者：侯增谦[1] 吕庆田[1] 王安建[2] 李晓波[3] 王宗起[4] 王二七[5] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]中国地质科学院,北京100037 [3]国土资源部信息中心,北京100812 [4]中国地质科学院地质研究所,北京100037 [5]中国科学院地质与地球物理研究所,北京100029

出　　处：《矿床地质》2003年第4期319-333,共15页Mineral Deposits

基　　金：国家基础研究规划 973项目"印度-亚洲大陆主碰撞带成矿作用"(编号 :2 0 0 2CB412 60 0 )资助

摘　　要：青藏高原碰撞造山带以其成矿规模大、形成时代新、矿床类型多、保存条件好诸特征而被誉为研究大陆成矿作用的天然实验室。文章基于青藏高原已有的矿产勘查与研究成果 ,概述了大陆碰撞过程中的主要成矿作用及其成矿带的时空分布 ,初步分析了陆_陆碰撞所造就的成矿背景和成矿环境以及控制成矿作用的关键地质过程 ,并草拟了可供今后研究的工作模型。初步研究认为 ,始于 6 0Ma的印度大陆与亚洲大陆碰撞至少形成了 3个重要的控矿构造单元 ,即雅鲁藏布江以北的主碰撞变形带 ,雅鲁藏布江以南的藏南拆离_逆冲带和高原东缘的藏东构造转换带。主碰撞变形带以巨大规模的地壳缩短、双倍地壳加厚、大规模逆冲系和SN向正断层系统发育为特征 ,控制了冈底斯斑岩铜矿带 (含浅成低温热液金矿 )、安多锑矿化带和风火山铜矿化带及腾冲锡矿带的形成及分布 ;藏南拆离_逆冲带由藏南拆离系 (STDS)和一系列北倾的叠瓦状逆冲断裂带构成 ,控制了藏南变质核杂岩型金矿化、热液脉型金锑矿化和蚀变破碎带型金锑矿化的形成 ;藏东构造转换带以发育大规模走滑断裂系统、大型剪切带、富碱斑岩带和走滑拉分盆地为特征 ,控制了玉龙斑岩铜矿带、哀牢山和锦屏山金矿带及兰坪盆地银多金属矿带的分布。按成矿系统的基本思想 ,初步将青藏高原碰撞?Metallogeny in the collisional orogen is an important research frontier for economic geologists both in China and abroad. The Himalayan_Tibetan orogen, which is characterized by the occurrence of large_scale, intense and young mineralizations as well as various kinds of large_size and weakly reformed deposits, is regarded as an ideal field for understanding ore_forming processes in collisional orogens. Based on data available and the authors' preliminary research results, this paper describes geological features and temporal_spatial distribution of important ore deposits in the Tibetan orogen, discusses geodynamic settings, mineral environments, and key geological processes governing the formation of these deposits, and proposes a possible working model for metallogeny in the Tibetan orogen. It seems that the Indo_Asian continent collision since 60 Ma resulted at least in the formation of three significant tectonic units controlling the development of ore deposits in the Tibetan orogen. They are: (1) the main collisional deformation zone north of IYS, (2) the southern Tibet detachment_thrust zone south of IYS, and (3) the eastern Tibet tectonic transformation zone. In the main collisional deformation zone characterized by the development of large_scale crustal shortening, thickening and thrusting as well as SN_striking normal faulting systems across the zone, there have occurred since Paleocene the Gangdese porphyry (_epithermal) Cu_ (Au) belt, the Ando Sb mineralization belt and the Fenghuoshan sandstone Cu mineralization belt in Tibet, and the Tengchong Sn belt in western Yunnan. In the southern Tibet detachment_thrust zone, the STDS and a series of thrusting systems control the Au_Sb hydrothermal mineralizations related to metamorphic core_complexes and tectonic_controlled fracture zones. Characterized by the development of large_sized strike_slip faulting systems constraining the localization of ore_bearing potassic porphyry intrusion groups, large_sized shear belts and strike_slip pull_apart basins in the

关 键 词：陆-陆碰撞 成矿作用 青藏高原造山带 地质学 矿床类型 

分 类 号：P611[天文地球—矿床学] P542[天文地球—地质学]