安徽金寨县沙坪沟钼铅锌矿田两期成岩成矿作用
DOI:
作者:
作者单位:

作者简介:

通讯作者:

中图分类号:

基金项目:

安徽省公益性地质(科技)项目(2009-g-19)、安徽省国土资源科技项目(2011-k-1)


Two Stages of Diagenesis and Metallogenesis of Shapinggou Molybdenum Lead Zinc Ore Field in Jinzhai County, Anhui Province
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:

    安徽金寨县沙坪沟钼矿床是近年来秦岭-大别成矿带发现的超大型斑岩钼矿床,已探明钼资源储量234×104t。在沙坪沟钼矿床外围发育多处铅锌矿床(点)。本文通过对外围3个铅锌矿床闪锌矿Rb Sr同位素定年,获得120±2Ma的成矿年龄,而钼矿床成矿年龄则在115~111Ma,显示出矿田内铅锌矿床的成矿时代早于钼矿床。结合区域构造背景、控矿构造、赋矿围岩及围岩蚀变等地质特征分析,认为斑岩钼矿床和铅锌矿床为两个独立的成矿系统,热液型铅锌矿成矿系统形成早于斑岩型钼矿成矿系统。据地质勘查和同位素年代学资料,矿田岩浆岩分为两期,第一期为早白垩世早期花岗闪长岩、二长花岗岩,是热液型铅锌矿成矿系统主要赋矿围岩,第二期为早白垩世晚期石英正长岩和花岗斑岩,是斑岩型钼矿成矿系统的主要赋矿围岩。矿床C、H、O、S等稳定同位素相关研究表明热液型铅锌矿成矿系统和斑岩型钼矿成矿系统均是两期岩浆热液演化的结果。因此矿田存在两期成岩成矿作用。两个成矿系统矿石铅同位素组成不同,斑岩型钼矿成矿系统矿石铅同位素比值相对较高,变化范围大。铅锌矿床为早于斑岩钼矿床的独立成矿系统的认识合理解释了沙坪沟钼矿床为单一钼矿体,不含铅锌铜等不同于东秦岭斑岩钼矿床地质现象。区内两期成岩成矿作用均发生于晚侏罗─早白垩世构造体制转换阶段及以后伸展期。

    Abstract:

    The Shapinggou porphyry type molybdenum deposit, located in Jinzhai County of Anhui Province, is a giant ore deposit discovered in the Qinling Dabie metallogenic belt in recent years, with proved reserves of molybdenum resource being 234 million tons. Several lead zinc deposits (mineralization occurrences) have been discovered in this area. Rb Sr isotopic dating for three sphalerites from the Zn Pb deposit yields a metallogenic age of 120±2Ma and dating for Mo deposit is around 115~111Ma, indicating the lead zinc deposit formed earlier than the molybdenum deposit. On the basis of regional tectonic background, ore controlling structure, ore bearing country rock and country rock alteration etc, it can be proposed that molybdenum deposit and lead zinc deposit formed from two different metallogenic systems, with hydrothermal lead zinc deposit formed earlier than porphyry molybdenum deposit. The geological survey and isotopic chorological data show that magmatic rocks formed likely from two magmatic events. The magmatic rock in the first stage consists of granodiorite and monzonitic granite in the early Early Cretaceous, both of which are the host rocks for hydrothermal Pb Zn metallogenic system. The rock in the second stage contains syenite and granite porphyry in the late Early Cretaceous, both of which constitute the main host rocks for porphyry type Mo metallogenic system. Stable isotope study of C, H, O and S shows that the hydrothermal lead zinc mineralization and the porphyry type molybdenum deposit were the result of two stage magma epithermal evolution. There two stages of diagenesis and mineralization may occur in this ore field. Also, two kinds of metallogenic systems have different lead isotope compositions of ore, while the metallogenic system of porphyry molybdenum deposit has higher lead isotope ratios with a wide range of change. The idea that hydrothermal lead zinc deposit was formed earlier than the porphyry molybdenum deposit can reasonably explain the geological phenomenon of why the Shapinggou molybdenum deposit contains only molybdenum orebodies without Pb, Zn and Cu etc. All those are different from the molybdenum deposits of the East Qinling. The two stages of diagenesis and mineralization in this area all took place in the transformation period of tectonic regime and post extension period in the late Jurassic to early Cretaceous.

    参考文献
    相似文献
    引证文献
引用本文

陆三明,阮林森,赵丽丽,王波华,张怀东,王国光,陈芳.2016.安徽金寨县沙坪沟钼铅锌矿田两期成岩成矿作用[J].地质学报,90(6):1167-1181.
LU Sanming, RUAN Linsen, ZHAO Lili, WANG Bohua, ZHANG Huaidong, WANG Guoguang, CHEN Fang.2016. Two Stages of Diagenesis and Metallogenesis of Shapinggou Molybdenum Lead Zinc Ore Field in Jinzhai County, Anhui Province[J]. Acta Geologica Sinica,90(6):1167-1181.

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:2015-05-14
  • 最后修改日期:2015-08-07
  • 录用日期:2016-06-28
  • 在线发布日期: 2016-06-28
  • 出版日期: