甘肃礼县中川地区金矿流体的来源与成因  

Origin and genesis of gold ore fluid in Zhongchuan area,Li County,Gansu Province

作　　者：姜启明[1] Jiang Qiming(Gansu Industry Polytechnic College,Tianshui,Gansu 741025)

机构地区：[1]甘肃工业职业技术学院,甘肃天水741025

出　　处：《地质科学》2022年第2期510-523,共14页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：甘肃省矿产资源补偿费项目(编号:2009-15)资助。

摘　　要：甘肃省礼县中川地区属于礼(县)岷(县)金矿带的东段,其成矿作用与中川花岗杂岩体有密切的关系。此次研究在已知金矿体上采集标本,碎样后挑选石英晶体,运用英国Micromass公司生产的MM5400质谱计,在1600℃条件下,让石英释放稀有气体,测量其中的^(4)He、^(20)Ne、^(40)Ar等稀有气体,通过稀有气体的示踪作用,研究成矿流体的来源。测试结果表明:礼县中川地区金矿的成矿流体中的^(4)He和^(40)Ar来源于中川花岗杂岩体;Ar同位素比值符合地壳流体特征;在^(3)He/^(4)He‑^(4)He/^(20)Ne体系图上,7个样品中,有4个点位于100%地壳流体来源线上,3个点位于5%上地幔与30%上地幔流体之间,说明成矿热流成分主要是地壳流体,含有10%左右的上地幔热流,即礼县中川地区金矿成矿流体具有混合热液特征。Zhongchuan gold deposit located in Li County,Gansu Province belongs to the eastern section of the Li-Min County metallogenetic belt,whose mineralization has close affinities with Zhongchuan granite complex.Samples were collected from known gold ore bodies,and quartz crystals were selected after crushing samples.Using the MM5400 mass spectrometer produced by Micromass Company,we measured the noble gases such as ^(4)He,^(20)Ne and ^(40)Ar releasing from quartz crystals at 1600℃ to study the source of ore-forming fluid.The results show that:1)^(4)He and ^(40)Ar in the ore-forming fluids of Zhongchuan gold deposit are derived from Zhongchuan granite complex;2)the Ar isotope ratios correspond to the characteristics of crustal fluid;3)on the ^(3)He/^(4)He-^(4)He/^(20)Ne diagram,among the 7 samples,there are 4 points on the 100%crustal line,and 3 points between 5%and 30%upper mantle line,indicating that the ore-forming fluid is mainly composed of crustal fluid and contains about 10%upper mantle fluid contribution,that is,the gold ore-forming fluid in Zhongchuan area of Lixian County has the characteristics of mixed hydrothermal solutions.

关 键 词：金矿床 中川花岗杂岩体 稀有气体 成矿流体 

分 类 号：P611[天文地球—矿床学]