矿床地质2018，Vol.37Issue(3)：521-534,14.DOI:10.16111/j.0258-7106.2018.03.005
内蒙古哈达门沟金矿成矿流体来源的氦、氩同位素示踪
Helium and argon isotopic tracing for sources of ore-forming fluid in Hadamen'gou gold deposit, Inner Mongolia
摘要
Abstract
Located in the Wulashan-Daqingshan area on the north margin of the North China Craton,the Hadamen'gou large-sized gold deposit is hosted in the biotite-hornblende-plagioclase gneiss,hornblende-biotite monzonite gneiss and garnet-biotite-plagioclase gneiss of the Wulashan Group.The characteristics of ore-forming fluid are unknown.In this paper,the authors analyzed the helium and argon isotopic compositions of fluid inclusions in pyrite.The 4He content ranges from 83.92 × 10-8 cm3STP/g to 606.46 × 10-8 cm3STP/g,the n(3He)/n(4He) ratios are between 0.19 Ra and 0.91 Ra,and the content of He derived from the mantle ranges from 2.62％ to 13.73％ with an average value of 9.95 ％;all of these characteristics suggest that the He in ore-forming fluids was mainly derived from the crust with about 10％ from the mantle.The 40Ar content ranges from 71.22 × 10-8 cm3 STP/g to 308.22 × 10-8 cm3STP/g,the n(40Ar)/n(36Ar) ratios are between 2793.6 and 7253.5,and the diagrams of n(40 Ar)/n(36Ar) versus R/Ra and n(40Ar*)/n(4He) versus R/Ra show the mixed source of the crust and the mantle Ar.Based on a comprehensive analysis of hydrogen,oxygen and sulfur isotopic characteristics of the Hadamen'gou gold deposit,it can be concluded that the ore-forming fluid was a mixture of crustal-derived fluid and mantle-derived magmatic fluid,with the former being dominant.In addition,the Urad Front Banner-Hohhot fault probably provided the channel and power for the migration of the K-feldspar-enriched and crust-mantle mixed fluid.关键词
地球化学/成矿流体/氦、氩同位素/黄铁矿/哈达门沟/内蒙古Key words
geochemistry/ore-forming fluid/helium and argon isotopes/pyrite/Hadamen'gou/Inner Mongolia分类
天文与地球科学引用本文复制引用
李志丹,李效广,段超,陈军强,王佳营,俞礽安,张祺,文思博,张超..内蒙古哈达门沟金矿成矿流体来源的氦、氩同位素示踪[J].矿床地质,2018,37(3):521-534,14.基金项目
本文得到中国地质调查局地质大调查项目(编号:12120113057300 （）
DD20160129)和国家自然科学基金项目(编号:41502082)联合资助 （编号:41502082）
