Sanjiang Tethyan metallogenesis in S.W. China: Tectonic setting, metallogenic epochs and deposit types
Sanjiang Tethyan metallogenesis in S.W. China: Tectonic setting, metallogenic epochs and deposit types
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DOI：
10.1016/j.oregeorev.2004.12.007
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发表时间：
2007-04
影响因子：
3.3
通讯作者：
Z. Hou;K. Zaw;G. Pan;X. Mo;Qiang Xu;Yunzhong Hu;Xingzhen Li
中科院分区：
文献类型：
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作者：
Z. Hou;K. Zaw;G. Pan;X. Mo;Qiang Xu;Yunzhong Hu;Xingzhen Li
从构造上看，三江特提斯成矿域位于中国西南部三江特提斯的东喜马拉雅-藏期造山带内。虽然该成矿域始于早古生代，但广泛的成矿作用发生在晚古生代、晚三叠世和喜马拉雅(第三纪)时代。与之对应的构造背景和环境有：与古特提斯洋板俯冲有关的弧盆体系；晚三叠世三江特提斯下岩石圈拆沉或板片断裂导致的碰撞后地壳伸展环境；古新世以来印亚大陆碰撞导致的大规模走滑断裂和逆冲体系。在这个成矿域中，发育了重要的金、铜、贱金属、稀有金属和锡矿带，蕴藏着大量的巨型矿床。矿床类型主要有：(1)受大型走滑断裂系统控制的斑岩型铜矿床；(2)VHMS矿床，主要赋存于弧内裂谷盆地和碰撞后地壳伸展盆地中；(3)沿逆冲-剪切系统的蛇绿混杂岩带中的剪切带型金矿；(4)三叠纪陆内裂谷盆地和第三纪走滑拉分盆地中的热液银多金属矿床；(5)与喜马拉雅花岗岩有关的云英岩型锡和稀有金属矿床。在晚古生代-新生代成矿时代，矿床的类型和样式由晚古生代的VHMS型矿床转变为晚三叠世的喷气-沉积型矿床，到新生代为斑岩型铜矿床、剪切带型金矿床、热液脉型银多金属矿床、云英岩型锡矿床和稀有金属矿床。相应地，成矿金属也由原来的铅-锌-铜-银组合转变为银-铜-铅-锌、铁-银-铅和银-金-汞组合，由银-铜-铅-锌、铜-钼、金、锡、锂-Rb-Cs-Nb-Zr-Hf-Y-Ce-Sc组合转变为银-铜-铅-锌、铜-钼、金、锡和Li-Rb-Cs-Nb-Zr-Hf-Y-Ce-Sc组合。
Tectonically, the Sanjiang Tethyan Metallogenic Domain (STMD) is located within the eastern Himalayan–Tibetan Orogen in the Sanjiang Tethys, southwestern China. Although this metallogenic domain was initiated in the Early Palaeozoic, extensive metallogenesis occurred in the Late Palaeozoic, Late Triassic and Himalayan (Tertiary) epochs. Corresponding tectonic settings and environments in the domain are: an arc-basin system related to the subduction of the Palaeo-Tethyan oceanic slabs; a post-collision crustal extension setting caused by the lithospheric delamination or slab breakoff underneath the Sanjiang Tethys during the Late Triassic; large-scale strike-slip faulting and thrusting systems due to the Indo-Asian continent collision since the Palaeocene. In this metallogenic domain important gold, copper, base metals, rare metals and tin ore belts, incorporating a large number of giant deposits, were developed. The main types of deposits include: (1) porphyry copper deposits, controlled by a large-scale strike-slip fault system, (2) VHMS deposits, mainly occurring in intra-arc rift basins and post-collision crustal extensional basins, (3) shear-zone type gold deposits in the ophiolitic mélange zone along the thrusting–shearing system, (4) hydrothermal silver-polymetallic deposits in the Triassic intra-continental rift basins and Tertiary strike-slip pull-apart basins, and (5) Himalayan granite-related greisen-type tin and rare-metallic deposits. Within the metallogenic epochs of the Late Palaeozoic to Cenozoic, the styles and types of the ore deposits changed from VHMS types in the Late Palaeozoic through exhalative-sedimentary type deposits in the Late Triassic, to porphyry-type copper deposits, shear-zone type gold deposits, hydrothermal vein-type silver-polymetallic deposits, greisen-type tin and rare-metal deposits in the Cenozoic. Correspondingly, ore-forming metals also changed from a Pb–Zn–Cu–Ag association through Ag–Cu–Pb–Zn, Fe–Ag–Pb and Ag–Au–Hg associations, to Ag–Cu–Pb–Zn, Cu–Mo, Au, Sn, and Li–Rb–Cs–Nb–Zr–Hf–Y–Ce–Sc associations.