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现代地质 ›› 2011, Vol. 25 ›› Issue (2): 219-227.

• 矿床学与同位素地球化学 • 上一篇    下一篇

新疆伽师砂岩型铜矿床地质及S、Pb同位素地球化学

王思程1,2,薛春纪1,李志丹1   

  1. 1.地质过程与矿产资源国家重点实验室,中国地质大学 地球科学与资源学院,北京100083;
    2.造山带与地壳演化教育部重点实验室,北京大学 地球与空间科学学院,北京100871
  • 出版日期:2011-04-25 发布日期:2011-05-13
  • 通讯作者: 薛春纪,男,教授,博士生导师,1962年出生,矿床学专业,主要从事矿床学、矿产普查与勘探专业的教学与研究。
  • 作者简介:王思程,男,学士,1989年出生,地质学专业,从事矿床地球化学研究。Email:wscnqqsforever@126.com。
  • 基金资助:

    国家科技支撑计划项目(2007BAB25B05, 2006BAB07B01); 高等学校学科创新引智计划项目(B07011); 长江学者和创新团队发展计划项目(IRT0755)。

Geology and S-, Pb-isotopic Geochemistry of the Jiashi Sandstone-type Copper Deposit, Xinjiang, China

WANG  Si-Cheng1,2,XUE  Chun-Ji1,LI  Zhi-Dan1   

  1. 1.State Key Laboratory of Geological Processes and Mineral Resources, School of Earth Sciences and Resources, China University
     of Geosciences, Beijing100083, China;  2.Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education,
    School of Earth and Space Sciences, Peking University, Beijing100871, China
  • Online:2011-04-25 Published:2011-05-13

摘要:

西南天山新生代山前盆地中的伽师铜矿是新疆近年发现和开发的一个重要的砂岩型铜矿,矿体产于古近系灰白色含岩屑钙质细砂岩中,呈与地层整合的板状、层状。矿石中硫化物主要为辉铜矿,矿体深部出现斑铜矿,极少量黄铁矿、闪锌矿等,硫化物多交代砂岩中胶结物或碎屑颗粒形成胶结结构,矿石发育稀疏浸染状、团块状、结核状等多种构造。矿石的硫同位素δ34SV-CDT在-33.4‰~-24.6‰之间。矿石的铅同位素组成206Pb/204Pb=18.376~18.607、207Pb/204Pb=15.612~15.655、 208Pb/204Pb=38.475~38.747。铜的硫化物矿化表现为含铜盆地流体(地下水)交代砂岩而沉淀,铜矿体形成于古近系细砂岩成岩晚期,矿石硫来源于细菌还原硫酸盐,矿石铅同位素组成指示成矿金属元素来自沉积盆地周围的蚀源区。

关键词: 矿床地质, S、Pb同位素, 砂岩型铜矿, 伽师铜矿, 新疆

Abstract:

The Jiashi copper deposit, located in Cenozoic piedmont basin system of southwestern Tianshan in Xinjiang, is an important sandstone-type copper deposit which has been discovered and mined recently.The ore bodies are tabular or stratiform in shape and occur in Neogene lightgrey detritusbearing calc-sandstone.The sulfide minerals in the ores are mainly chalcocite, fewer pyrite and sphalerite.Bornites occur at the deep part of the ore bodies.The ore shows disseminated, lumpish and nodular structures, and the sulfide minerals replaced the cemented calcites in the sandstone and formed a cemented texture.The ore δ34S V-CDT varies from -33.4‰ to -24.6‰.The 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb of ore sulfide vary from 18.376 to 18.607, 15.612 to 15.655 and 38.475 to 38.747, respectively.It is suggested that the Jiashi copper mineralization was a replacement of the sandstone by copperbearing basin fluid (underground water).The ore bodies formed during late diagenetic stage of the sandstone in Paleogene.The ore sulfur was derived from sulfate reduced by bacteria and the composition of the Pb isotope indicates that the metal were originated from the erosion source area around the sedimentary basin.

Key words: ore geology, S and Pb-isotopes, sandstone-type copper deposit, Jiashi copper deposit, Xinjiang

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