西藏班公湖- 怒江成矿带商旭金矿成矿时代探讨及其地质意义
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

基金项目:

本文为国家重点研发计划(编号2018YFC0604101、2018YFC0604106),中国地质调查局项目(编号DD20160026、DD20190167),公益性行业科研专项(编号201511017)、中国地质科学院基本科研业务费(编号YYWF201608),国家自然科学基金项目(编号41402178)和中国国家留学基金资助的成果。


Metallogenic epoch study on the Shangxu gold deposit, Bangong- Nujiang suture zone, Tibet and its geological implications
Author:
Affiliation:

Fund Project:

  • 摘要
  • |
  • 图/表
  • |
  • 访问统计
  • |
  • 参考文献
  • |
  • 相似文献
  • |
  • 引证文献
  • |
  • 资源附件
  • |
  • 文章评论
    摘要:

    造山型金矿在世界范围内具有重要的经济价值和找矿潜力,也是西藏班公湖怒江铜多金属资源基地的主攻矿床类型之一。班公湖怒江成矿带是近十年来识别和建立的我国最重要的斑岩浅成低温热液矽卡岩型铜金成矿带。商旭金矿位于班公湖怒江缝合带中段,是该成矿带上首例造山型金矿床。矿体产于中下侏罗统木嘎岗日群沉积岩,由石英脉、碳酸盐+石英脉和蚀变岩构成,呈透镜状、块状、条带状、鞍状、浸染状、角砾状等产出,受北西西向的区域断裂构造控制。热液蚀变发育碳酸盐化、白云母化、绿泥石化和硫化物蚀变等。矿物学研究和含矿脉体特征表明,早期热液活动发育于挤压应力环境,后期挤压应力逐渐消失,对应了变形晚期的构造环境。含金石英流体包裹体的Rb- Sr同位素测试获取的等时线年龄为135. 6±2. 7Ma,87Sr/86 Sr平均初始比值为0. 713,预示成矿作用发生于早白垩世,成矿物质主要来自地壳。综合研究认为,商旭金矿形成于早白垩世初班公湖怒江缝合带中段的闭合期,地块间挤压应力致使木嘎岗日群发生构造变形,在挤压变形晚期构造环境发生转换的过程,围岩中应力释放促成了区域的金矿化。对比研究显示,商旭金矿化与世界大型、超大型造山型金矿在矿床地质、热液蚀变特征、成矿流体性质、成矿构造环境、动力学背景等方面具有相似性,进一步表明班怒带具备寻找造山型金矿的潜力。

    Abstract:

    The orogenic gold deposit is globally an economically important mineralization and is thus the main objective of themineral exploration inthe Bangong- Nujiang Copper Polymetallic Resources Base. The Bangong- Nujiang metallogenic belt is one of the most important porphyry- epithermal- skarn copper and gold resource belt that has been recognized and developed in the recent decade in China. The Shangxu gold deposit, situated in the middle of the Bangong- Nujiang belt, is the first orogenic gold deposit in this metallogenic belt. Mineralization is hosted by the Early to Middle Jurassic turbidite of the Mugagangri Group, and comprised of quartz lodes, carbonate+quartz veins and altered rocks, with lentoid, massive, laminated, saddle, disseminated, brecciated structures. Mineralization is controlled by the NWW- stretching regional fault system. Hydrothermal alteration includes carbonatization, muscovitization, chloritization and sulfidation. The mineralogy and the characteristics of gold lodes indicate that the early hydrothermal activity developed in a compressional environment,and the compression stressdecreased and disappeared in the late hydrothermal stage. This could correspond to a late tectonic deformation setting. The Rb- Sr isotopes of quartz fluid inclusions lead to an isochron age of 135. 6±2. 7 Ma, with an average initial 87Sr/86 Sr value of 0. 713, indicating that mineralization developed in the Early Cretaceous, and the ore- forming materials were sourced from the crust. Integrated study shows that the formation of the Shangxu gold deposit was coincident with the closure of the middle Bangong- Nujiang suture during the Early Cretaceous. The compression stress between terranes caused regional deformation and metamorphism of the host rock of the Mugagangri Group. During thechanging tectonic setting in the late compression deformation, stress relief might have led to gold mineralization. A comparison study shows that the Shangxu gold mineralization shares similarities in deposit geology, hydrothermal alterations, ore- forming fluids, tectonic settings andgeodynamic settings with large and world- class orogenic gold deposits around the world, indicating the potential of orogenic gold mineralization along the Bangong- Nujiang belt.

    参考文献
    相似文献
    引证文献
引用本文

方向,宋扬,唐菊兴,王嘉星,李海峰.2020.西藏班公湖- 怒江成矿带商旭金矿成矿时代探讨及其地质意义[J].地质学报,94(11):3376-3390.
FANG Xiang, SONG Yang, TANG Juxing, WANG Jiaxing, LI Haifeng.2020. Metallogenic epoch study on the Shangxu gold deposit, Bangong- Nujiang suture zone, Tibet and its geological implications[J]. Acta Geologica Sinica,94(11):3376-3390.

复制
分享
文章指标
  • 点击次数:
  • 下载次数:
  • HTML阅读次数:
  • 引用次数:
历史
  • 收稿日期:2019-12-10
  • 最后修改日期:2020-06-01
  • 录用日期:2020-04-22
  • 在线发布日期: 2020-06-11
  • 出版日期: