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引用本文:毛景文 周振华 丰成友 王义天 张长青 彭惠娟 于 淼. 初论中国三叠纪大规模成矿作用及其动力学背景[J]. 中国地质, 2012, 39(6): 1437-1471.
MAO Jing-wen, ZHOU Zhen-hua, FENG Cheng-you, WANG Yi-tian, ZHANG Chang-qing, PENG Hui-juan, YU Miao. A preliminary study of the Triassic large-scale mineralization in China and its geodynamic setting[J]. Geology in China, 2012, 39(6): 1437-1471(in Chinese with English abstract).
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初论中国三叠纪大规模成矿作用及其动力学背景
毛景文 周振华 丰成友 王义天 张长青 彭惠娟 于 淼
中国地质科学院矿产资源研究所,北京 100037
摘要:
提要:三叠纪构造演化在中国地质历史过程中具有强度大、影响广泛的特点,然而与三叠纪重大构造事件有关的成矿作用研究明显滞后。本文基于最新研究成果,初步系统论述了中国三叠纪大规模成矿时空分布及基本特点。中国三叠纪金属矿产主要分布在昆仑—秦岭和红河—哀牢山两个三叠纪主造山带及其邻区,另外在华南、东北和新疆三个板内也发育有一系列多金属矿产。三叠纪矿床类型主要包括:①与基性-超基性岩有关的Cu-Ni硫化物矿;②与中酸性-酸性岩有关的斑岩Cu-Au、Cu-Mo、Mo矿,矽卡岩型Cu-Pb-Zn、Cu-Fe、Sn、W矿和脉状Au矿;③与高温气液-流体有关的伟晶岩型稀有金属矿;④与造山过程构造-热-流体有关的造山型Au矿;⑤与造山过程盆地流体有关的MVT型Pb-Zn矿;⑥与地幔流体有关的碳酸岩脉型Mo矿。昆仑—秦岭造山带内大多数三叠纪矿产都形成于碰撞造山或后碰撞环境,以前者为主。在东秦岭地区,三叠纪矿床以Mo、Au矿为主,形成时代集中在233~221 Ma;西秦岭地区三叠纪Au矿和Pb-Zn矿广泛分布,其中金矿受北西向脆韧性剪切构造带控制,而Pb-Zn矿集中出现在西成和凤太两大盆地内,成矿时代集中在晚三叠世(232~214 Ma);东昆仑地区新探明的一系列Cu-Mo-Fe多金属矿床,其成矿时代为240~210 Ma。红河—哀牢山造山带受新特提斯构造演化影响,三叠纪矿产呈零星出露,主要出现在中甸古岛弧区、造山带东侧的滇黔川接壤区和滇东南都龙地区。在中甸岛弧区整体表现为中部以斑岩-矽卡岩型Cu矿床为主,向南北两侧变为斑岩-浅成低温热液型Cu-Pb-Zn矿床和Au矿床,成岩成矿年龄集中于228~201 Ma;川滇黔地区近几年的测年结果显示出其主要的Pb-Zn矿都形成于三叠纪;滇东南都龙地区新近发现一组三叠纪W-Sn矿床,成矿时代集中在214~209 Ma。除两条主碰撞带外,三叠纪矿床还有华南稀有、W-Sn矿床,新疆稀有金属、Mo矿和东北及其邻区斑岩Mo矿、Cu-Ni硫化物矿和脉状Au矿等,其与板块碰撞的远程效应关系密切。其中,华南大多数三叠纪矿产与东西向构造-岩浆活动有关,来源于加厚地壳重熔形成的过铝质花岗岩上侵定位,而东北及其邻区、新疆及其毗邻的蒙古和俄罗斯阿尔泰及紧邻西伯利亚的三叠纪成矿作用则可能与地幔柱活动有关。
关键词:  三叠纪  成矿作用  碰撞造山  后碰撞  地幔柱  昆仑—秦岭造山带  红河—哀牢山造山带
DOI:
分类号:
基金项目:国家自然科学基金项目(40930419)和中国地质调查项目(121201112083和1212011085260)联合资助成果。
A preliminary study of the Triassic large-scale mineralization in China and its geodynamic setting
MAO Jing-wen, ZHOU Zhen-hua, FENG Cheng-you, WANG Yi-tian, ZHANG Chang-qing, PENG Hui-juan, YU Miao
Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China
Abstract:
Abstract:Triassic tectonic evolution in China is characterized by high intensity and wide influence. However, the metallogenic study related to the major Triassic tectonic events has obviously been lagging behind. This paper preliminarily and systematically discusses the space-time distribution and basic characteristics of the large scale Triassic mineralization in China based on the latest research achievements. Triassic deposits in China are distributed mainly in the two main Triassic orogenic belts of the Kunlun-Qinling orogenic belt and the Red River - Ailaoshan orogen belt and their adjacent regions; Besides, there are a series of polymetallic deposits developed in the three intraplates of southern China, northeastern China and Xinjiang area. Major types of Triassic deposits mainly include: ① Cu-Ni sulfide deposits related to basic-ultrabasic rock; ② porphyry Cu-Au, Cu-Mo, Mo deposits, skarn Cu-Pb-Zn, Cu-Fe, Sn, W deposits and vein-type Au deposits related to intermediate-acid rocks and acidic plutons; ③ pegmatite-type rare metal deposits related to high temperature gas-fluids; ④ orogenic Au deposits related to tectonic-hydrothermal activities in the orogenic process; ⑤ MVT Pb-Zn deposits related to basinal fluids in the orogenic process; ⑥ carbonated vein-type Mo deposits related to mantle fluids. Most of the Triassic deposits in the Kunlun-Qinling orogen belt were mainly formed in collisional stage, or in the post-collision setting. In East Qinling area, the Triassic deposits are dominated by Mo, Au, with the formation ages mainly concentrated in 233-221Ma. In contrast, Au deposits and Pb-Zn deposits of Triassic are widely distributed in West Qinling area, Au deposits are distributed along the NW-trending brittle-ductile shear zones, and Pb-Zn deposits are largely concentrated in the two targe basins of Xicheng and Fengtai, whose metallogenic epochs are mainly in the Late Triassic (232-214Ma). In East Kunlun area, newly discovered Cu-Mo-Fe polymetallic deposits were formed in 240-210 Ma. Influenced by Neo-Tethys evolution, Triassic metal mineral resources are scattered in the Red River - Ailaoshan orogen belt, mainly distributed in Zhongdian ancient island arc, Yunnan-Guizhou-Sichuan border area in the east of the orogenic belt and Dulong area of southeast Yunnan. In Zhongdian area, the metallogenic ages are concentrated in 228-201Ma and their distribution shows the characteristics of porphyry-skarn Cu deposits in the middle part and porphyry-epithermal Cu-Pb-Zn deposits and Au deposits on both north and south sides. The dating results obtained in recent years indicate that Pb-Zn deposits in Yunnan-Guizhou-Sichuan border area were mainly formed in Triassic. Moreover, a series of Triassic W-Sn deposits have been discovered recently in Dulong area of southeast Yunnan, whose peak age is 214-209Ma. In addition to the two main collision belts, rare metal and W-Sn deposits in South China, rare metal and Mo deposits in Xinjiang, porphyry Mo deposits, Cu-Ni sulfide deposits and vein type Au deposits in Northeast China and its adjacent areas were also formed in Triassic, and all of these deposits were closely related to the collision regime, most Triassic deposits in South China were related to EW-extending tectonic-magmatic systems and derived from the emplacement of aluminum granite resulting from the remelting of thickened crust. The mineralization of Triassic deposits in Northeast China and its adjacent areas, Xinjiang, and some neighboring areas of Mongolia and Russian Altay as well as Siberia were probably related to mantle plume activities.
Key words:  Triassic  mineralization  collision orogeny  post-collision  mantle plume  Kunlun-Qinling orogen belt  Red River - Ailaoshan orogen belt