西北地质2018，Vol.51Issue(1)：255-264,10.
西秦岭大桥金矿硅质岩硅氧同位素特征及成因探讨
Si-O Isotopic Characteristics and Genesis of the Siliceous Rocks from the Daqiao Gold Deposit in West Qinling
摘要
Abstract
The Daqiao gold deposit is situated between the Minxian-Dangchang and Zhouqu-Chengxian regional faults in west Qinling.The ore-body is hosted within the siliceous breccia at the lithological unconformity interface between limestone and argillaceous slate in the lower part of Triassic strata.The breccia shows layered,tabular and lenticular shapes,occurring in the both side of the fault.The ore structures include primarily breccia,quilt-membrane,crusty,veinstockwork and pore.The ore minerals are mainly pyrite,binarite,pyrrhotite,arsenopyrite,sphalerite,galena and chalcopyrite.The alterations of country rocks are composed of silicification,sericitization and calcilization.The element associations related to the mineralization are Au,Sb,Ag,As,Hg and W.By the oxygen isotope thermometer,the estimated formation temperatures of these siliceous rocks are around 142-218℃,their δ30 Si and δ18 O values are-0.7‰-0.4‰ and 12.8‰-17.9‰,respectively,which are similar to the ones of the hot spring gold deposits.Combined with other geological characteristics,it's believed that the siliceous rocks are formed by rock fracturing due to fluid overpressure under the hot-spring environment nearby the periodic fault zone.关键词
大桥金矿/硅质岩/硅氧同位素成因Key words
Daqiao gold deposit/siliceous rock/genesis of silicon and oxygen isotopes分类
天文与地球科学引用本文复制引用
滕飞,刘云华,李中会,张忠平,罗根根,魏居珍..西秦岭大桥金矿硅质岩硅氧同位素特征及成因探讨[J].西北地质,2018,51(1):255-264,10.基金项目
中国地质调查局国土资源大调查项目“秦岭成矿带矿产资源潜力调查”([2014]01-006-010) （[2014]01-006-010）
