| 湘中古台山金锑矿床变形序列、成矿事件及控矿构造 |
| Received:March 30, 2022 Revised:February 10, 2023 点此下载全文 |
| 引用本文：BAI DaoYuan,LI Bin,JIANG Can,DUAN AiJun.2023.Deformation sequences, metallogenic events and ore-controlling structures at Gutaishan Au-Sb deposit in Central Hunan Province[J].Mineral Deposits,42(2):229~252 |
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| Author Name | Affiliation | | BAI DaoYuan | Hunan Institute of Geology Survey, Changsha 410016, Hunan, China | | LI Bin | Hunan Institute of Geology Survey, Changsha 410016, Hunan, China
State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, Jiangxi, China | | JIANG Can | Hunan Yukun Mining Group Company with Limited Liability, Xinhua 417600, Hunan, China | | DUAN AiJun | Hunan Yukun Mining Group Company with Limited Liability, Xinhua 417600, Hunan, China |
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| 基金项目:本文得到湖南省地质院科研项目（编号：201917）资助 |
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| 中文摘要:湘中古台山金锑矿位于雪峰构造带西南段东北部，发育SN向金矿脉和NW向金锑矿脉2类矿脉。前人提出SN向和NW向断裂为容矿构造，并获得了印支期成矿的40Ar-39Ar同位素年龄，但对容矿断裂的性质、形成时代以及2类矿脉的时代关系缺乏研究和认识。鉴于此，文章通过地表和井下露头构造以及矿化蚀变的观测、解析，结合区域构造特征、区域构造演化和测年资料等，厘定了古台山金锑矿区构造变形序列及其时代、不同类型矿脉的成矿时代和构造背景，探讨了构造控矿规律及动力机制。主要认识如下：①研究区自早至晚经历了5期主要变形事件：志留纪晚期受到NWW向挤压，形成NNE向板劈理、NNE向褶皱（水车背斜）、SN向顺层断裂、逆冲剪切破裂和断裂；中三叠世晚期受到NNW向挤压，局部形成NEE向轴面劈理；晚三叠世受到SN向挤压，形成EW向褶皱、NW向—NNW向右行走滑断裂和剪切破裂、NNE向左行走滑断裂和剪切破裂、EW向逆冲剪切破裂等；中侏罗世晚期受到NWW向挤压，形成EW向右行剪切破裂和断裂；古近纪中晚期受到NE向—NNE向挤压，形成SN向—NNE向右行剪切破裂和断裂、EW向—NEE向左行剪切破裂和断裂、NE向左行剪切破裂等；② SN向金矿脉形成于印支晚期（晚三叠世），NW向金锑矿脉形成于燕山期（晚侏罗世）；2类不同矿脉在空间上共生可能与不同成矿阶段的埋深差异有关；③ NNE向水车复背斜和白马山-龙山EW向隆起相关的NNE向、EW向隐伏大断裂和花岗岩体，以及郴州-邵阳NW向基底隐伏大断裂，为矿床定位提供了良好的构造条件；④导矿构造为晚三叠世NNE向左行走滑断裂；金矿脉的容矿构造为志留纪晚期的SN向逆断裂，金锑矿脉的容矿构造为晚三叠世NW向右行走滑断裂；NNE向断裂的左行走滑，导致SN向和NW向含矿断裂局部偏转为NNW向和NWW向。 |
| 中文关键词:地质学 变形序列 成矿时代 控矿构造 动力机制 古台山金锑矿床 湖南 |
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| Deformation sequences, metallogenic events and ore-controlling structures at Gutaishan Au-Sb deposit in Central Hunan Province |
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| Abstract:The Gutaishan Au-Sb deposit in central Hunan Province is located in the northeast of the southwest section of Xuefeng structural belt, with two types of veins such as SN-trending Au veins and NW-trending Au-Sb veins developed. Predecessors proposed SN- and NW-trending faults as ore-bearing structures, and obtained the 40Ar-39Ar isotopic age indicating Indosinian mineralization. However, there is a lack of research and understanding on the features and ages of ore bearing-faults and the age relationship between the two types of ore veins. In view of this, the authors carried out detailed observation and analysis of surface and underground outcrop structures and mineralization alteration, and combined with regional structural characteristics, regional structural evolution and dating data, determined the deformation sequences and their ages, the metallogenic ages and tectonic setting of different types of veins in the Gutaishan Au-Sb mining area, discussed the structural ore-controlling regularity and dynamic mechanisms. The main achievements are as follows:① The study area has experienced five main deformation events:Regional NWW compression during late Silurian which formed NNE-trending slaty cleavages, NNE-trending fold (the Shuiche anticline), SN-trending bedding-parallel faults, thrust shear fractures and faults; regional NNW compression in the late Middle Triassic which formed NEE-trending axial cleavages locally; regional SN compression in the Late Triassic which formed EW-trending folds, NW- to NNW-trending dextral strike-slip faults and shear fractures, NNE-trending sinistral strike-slip faults and shear fractures, EW-trending thrust shear fractures; regional NWW compression in the late Middle Jurassic which formed EW-trending dextral shear fractures and faults; regional NE to NNE compression in the middle-late Paleogene which formed SN- to NNE-trending dextrall shear fractures and faults, EW- to NEE-trending sinistral shear fractures and fault, and NE-trending sinistral shear fractures. ② SN-trending Au veins were formed in late Indosinian (Late Triassic) and NW-trending Au-Sb veins were formed in Yanshanian (Late Jurassic); the spatial association of the two different types of veins may be related to the depth difference in different metallogenic stages. ③ NNE-trending and EW-trending concealed faults and granite bodies related to NNE-trending Shuiche anticline and Baimashan-Longshan EW-trending uplift, and Chenzhou-Shaoyang NW-trending basement concealed fault provide good structural conditions for the positioning of the deposit. ④ The ore-passing structure is the Late Triassic NNE-trending sinistral strike-slip faults; the ore-bearing structure of the Au veins is SN-trending reverse faults formed in the late Silurian, and the ore-bearing structure of the Au-Sb veins is NW-trending dextral strike-slip faults formed in Late Triassic; sinistral strike-slip of the NNE-trending faults leads to the partial deflection of the SN-trending and NW-trending ore-bearing faults to NNW-trending and NWW-trending respectively. |
| keywords:geology deformation sequences ore-forming epoch ore-controlling structures dynamic mechanisms Gutaishan Au-Sb deposit Hunan |
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