陕西省凤县温江寺金矿地质地球化学特征及找矿

Geological and geochemical characteristics and prospecting work of the Wenjiangsi gold deposit,Fengxian County,Shaanxi Province

温江寺金矿是西秦岭东部地区三叠纪地层中新发现的一个金矿。容矿地层主要是钙质板岩和含炭钙质板岩。矿(化)体呈透镜状、扁豆状分布于钙质板岩和炭质板岩中。区内成矿元素为Au、As、Sb、Hg、Pb、Zn等低温蚀变组合,地质特征显示出微细浸染型金矿特征。各类岩(矿)石的地球化学分析表明,从矿石到泥质板岩再到花岗岩脉,Al2O3和K2O+Na2O含量逐渐升高,而CaO含量、K2O/Na2O具降低趋势;矿石中As、Bi、Co、Ni、Cu、W、V、Tu、U等微量元素含量和ΣREE、LREE/HREE、稀土配分模式与容矿地层相近,而与花岗岩脉不同。地球化学特征显示,温江寺金矿成矿物质主要来源于容矿地层,与岩浆活动关系不密切。该金矿的发现,使得西秦岭三叠系沉积建造中金矿找矿有进一步向东延伸的可能。

The Wenjiangsi ore deposit in the eastern extension of the West Qinling oroganic belt is a newly-discovered gold deposit hosted in a Triassic（carbon-bearing） calcareous slate sequence.Lenticular ore bodies and ore spots are characterized by disseminated mineralization with Au-As-Sb-Hg-Pb-Zn low-temperature assemblages.From the ore and argillaceous slate to granite veins,Al2O3 and alkaline components（K2O ＋ Na2O） increase,accompanied by decreasing of CaO and K2O/Na2O.Trace elements（e.g.,As,Bi,Co,Ni,Cu,W,V,Tu and U） and REE patterns（ΣREE,LREE/HREE） of disseminated ores are similar to things of hosted calcareous slates,indicating that metals were derived from hosting strata instead of from magmatic intrusions.The discovery of the Wenjiangsi gold deposit makes it possible for further eastward extension of the West Qinling Triassic sequence.