地学前缘 ›› 2020, Vol. 27 ›› Issue (2): 254-275.DOI: 10.13745/j.esf.sf.2020.3.21

• 特色地域成矿背景与成矿作用 • 上一篇    下一篇

新疆东准噶尔卡拉麦里造山型金成矿系统与区域构造演化

顾雪祥1,2(), 章永梅1,2, 葛战林3, 陈伟志4, 徐劲驰1, 黄岗5, 陶威5   

  1. 1.中国地质大学(北京) 地球科学与资源学院, 北京 100083
    2.中国地质大学(北京) 地质过程与矿产资源国家重点实验室, 北京 100083
    3.中国人民武装警察部队 武警黄金第五支队, 陕西 西安 710100
    4.中国人民武装警察部队 武警黄金第十支队, 云南 昆明 650100
    5.陕西省地勘局 区域地质矿产研究院, 陕西 咸阳 712000
  • 收稿日期:2019-12-18 修回日期:2020-02-22 出版日期:2020-03-25 发布日期:2020-03-25
  • 作者简介:顾雪祥(1964—),男,教授,博士生导师,主要从事矿床学和地球化学研究。E-mail: xuexiang_gu@cugb.edu.cn
  • 基金资助:
    国家自然科学基金项目(41572062);国家重点研发计划项目(2018YFC0604003)

The orogenic Au mineralization system and regional tectonic evolution in the Kalamaili area, East Junggar, Xinjiang

GU Xuexiang1,2(), ZHANG Yongmei1,2, GE Zhanlin3, CHEN Weizhi4, XU Jingchi1, HUANG Gang5, TAO Wei5   

  1. 1. School of Earth Sciences and Resources, China University of Geosciences (Beijing), Beijing 100083, China
    2. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Beijing), Beijing 100083, China
    3. No.5 Gold Geological Party of Chinese People’s Armed Police Force, Xi'an 710100, China
    4. No.10 Gold Geological Party of Chinese People’s Armed Police Force, Kunming 650100, China
    5. Regional Institute of Shaanxi Bureau of Geological Exploration, Xianyang 712000, China
  • Received:2019-12-18 Revised:2020-02-22 Online:2020-03-25 Published:2020-03-25

摘要:

新疆东准噶尔卡拉麦里地区以金水泉、双泉、南明水、苏吉泉东等为代表的金矿床,构成了一套与晚古生代碰撞造山有关的金成矿系统。矿床夹持于区域性的卡拉麦里深大断裂和清水—苏吉泉大断裂之间,矿化受次级脆-韧性断层控制,以中等至陡倾斜的含金石英脉和破碎蚀变岩的形式产于晚古生代浅变质火山沉积岩中。流体包裹体、H-O-S-Pb同位素和热液锆石U-Pb年代学研究表明,成矿流体具中高温(集中于240~330 ℃)、低盐度(<6% NaCleq)、富CO2的变质流体特征,成矿物质来自赋矿的火山沉积岩系,流体不混溶(相分离)和水-岩反应(围岩硫化作用)是导致金沉淀的主要机制,成矿深度变化于7~15 km之间,成矿时代约为314 Ma。晚石炭世至早二叠世,研究区的构造体制由挤压向走滑或走滑伸展转换,构造应力的释放导致深部变质脱水形成的低盐度CO2-H2O-NaCl±CH4含金流体,沿走向NW至近EW向的走滑剪切断裂向地壳浅部流动,并在脆-韧性过渡带或脆性变形带的次级断裂中形成含金石英脉及蚀变岩型金矿石。

关键词: 造山型金矿床, 成矿系统, 区域构造演化, 卡拉麦里, 东准噶尔, 新疆

Abstract:

Au deposits, including the Jinshuiquan, Shuangquan, Nanmingshui, and East Sujiquan Au deposits in the Kalamaili area of eastern Junggar, Xinjiang, constitute a mineralization system related to the late Paleozoic collisional orogeny. The deposits are sandwiched between the regional Kalamaili and Qingshui-Sujiquan faults. Au mineralization is controlled by the subsidiary brittle-ductile faults in slightly metamorphosed, late Paleozoic volcanic sedimentary rocks, and typically occurs as medium-to-steep dipping auriferous quartz veins and surrounding altered rocks. Fluid inclusions, H-O-S-Pb isotopes, and hydrothermal zircon U-Pb dating indicate that the ore-forming fluids are characterized by medium-to-high temperature (mostly 240-330 ℃), low salinity (<6 wt% NaCleq), and CO2-rich metamorphic water. The ore-forming material was sourced from host volcanic sedimentary rocks. Fluid immiscibility (phase separation) and fluid-rock interaction (wall-rock sulfidation) are the principal mechanisms of Au deposition. The timing of mineralization was approximately 314 Ma, and mineralization depths ranged from 7 to 15 km. From the Late Carboniferous to Early Permian, the transition of the tectonic system from compression to strike-slip or strike-slip extension in the study area resulted in the migration of deep metamorphic auriferous CO2-H2O-NaCl±CH4 fluids to shallower depths along NW- to EW-trending strike-slip faults. Au precipitation in the subsidiary faults of the brittle-ductile transition zone or brittle deformation zone led to the formation of auriferous quartz veins and related altered rock ores.

Key words: orogenic gold deposits, mineralization system, regional tectonic evolution, Kalamaili, eastern Junggar, Xinjiang

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