| 四川丹巴县独狼沟金矿床成因：来自同位素证据 |
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| 引用本文： | 凡,韬.四川丹巴县独狼沟金矿床成因：来自同位素证据[J].地质与勘探,2023,59(3):481-496. |
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| 作者姓名： | 凡 韬 |
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| 作者单位： | 四川省第七地质大队，四川乐山；四川省深地资源勘查开发研究院，四川乐山；张建东劳模创新工作室，四川乐山 |
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| 摘 要： | 四川丹巴县独狼沟金矿床是扬子陆块西缘金成矿带上的一个大型金矿床。矿体呈较高品位、较厚单体石英脉充填于构造破碎带之间，呈透镜状、似层状和层状产出，受断层构造影响极为明显，具热液矿床特征。矿物学、锆石U-Pb测年成果和稀土元素及微量元素等方面研究显示矿床主要受两期热液成矿作用影响，早期热液成矿作用形成以磁黄铁矿、黄铁矿等高温热液矿物为主的金矿体，时限限定于184.2±1.1 Ma；晚期热液成矿作用则形成以黄铜矿、叶碲铋矿等中温热液矿物为主的金矿体，时限限定于156.5±4.3 Ma。成矿流体氢氧同位素组成表明其与该时期区域岩浆作用存在一定关联而与区域变质作用关系不密切。S同位素组成反映出其来源为深部来源的属性，在Pb同位素组成的研究中也对这一观点进行了验证。成矿流体被认为是来自交代岩石圈地幔，在早侏罗世软流圈上涌事件影响下交代岩石圈地幔中挥发分上涌并活化上覆地层中的金，从而形成富金成矿流体并沿区域性深大断裂上移就位于地壳岩石地层中成矿。成矿动力学机制与区域碰撞造山后由挤压向伸展转换的大地构造背景密切关联，认为独狼沟金矿床为典型造山型金矿床。
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| 关 键 词： | U-Pb锆石年代学 岩石化学 同位素地球化学 矿床成因 独狼沟金矿 丹巴县 四川省 |
| 收稿时间： | 2022/7/23 0:00:00 |
| 修稿时间： | 2023/3/30 0:00:00 |
Genesis of the Dulanggou gold deposit in Danba County of Sichuan Province:Based on isotopic evidence |
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| Fan Tao.Genesis of the Dulanggou gold deposit in Danba County of Sichuan Province:Based on isotopic evidence[J].Geology and Prospecting,2023,59(3):481-496. |
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| Authors: | Fan Tao |
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| Institution: | No.7th Geological Brigade of Sichuan Province,Leshan, Sichuan; Research Institute of Deep Resources Exploration and Development,of Sichuan Provice,Leshan,Sichuan; Zhang Jiandong Model Worker Innovation Studio,Leshan, Sichuan |
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| Abstract: | The Dulanggou gold deposit in Danba County of Sichuan Province is a large gold deposit in the western Yangtze margin gold
metallogenic belt. The ore bodies occur in thick high-grade quartz veins in structural fracture zones, and display lenticular, stratiform-like and
stratiform shapes. They show a significant control by fault structures, and are typical of hydrothermal deposits. This work conducted mineralogy, zircon
U-Pb dating, REE and trace element analysis on the rocks and ores from the deposit to reveal the deposit genesis. Results show that the deposit was
mainly affected by two-stage hydrothermal mineralization. The early hydrothermal mineralization formed gold orebodies dominated by pyrrhotite, pyrite
and other high-temperature hydrothermal minerals, with a time limit of 184.2±1.1Ma. The late hydrothermal mineralization resulted in the formation of
gold orebodies dominated by chalcopyrite, tellurite bismuth and other mesothermal hydrothermal minerals, with a time limit of 156.5±4.3 Ma. H-O
isotopic analysis indicates that the ore-forming fluids do not correlate with metamorphism, but have some certain correlation with regional magmatism in
this period. S isotopic composition reflects the attribute of deep source, which has also been verified by lead isotopic composition. Ore-forming fluids are
inferred to be originated from metasomatic lithospheric mantle. Under the influence of Early Jurassic asthenosphere upwelling, volatiles from lithosphere
mantle were subjected to metasomatism, and upwelled and activated gold in overlying strata. As a result, gold-rich ore-forming fluids were formed,
which then moved upward along regional deep faults and located in crustal rock strata. The metallogenic dynamics is closely related to the transitional
tectonic environment from compressional to extensional tectonic environment after regional orogeny. These evidences indicate that The Dulanggou gold
deposit is a typical orogenic gold deposit. |
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| Keywords: | U-Pb zircon chronology petrochemistry isotopic geochemistry genesis Dulanggou gold deposit Danba County Sichuan Province |
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