吉林省西林河王麻子沟金矿床地质特征及成因探讨

Geological characteristics and genesis of Xilinhe Wangmazigou Gold deposit,Fusong Jinlin.

王麻子沟金矿床成矿物质来源于中元古界老岭群达台山组地层及燕山期碱长花岗岩岩体。成矿作用先后经历同生沉积期、变质变形期、岩浆热液蚀变期、表生氧化期四个阶段。矿体铅同位素年龄7.43亿年,推测变质变形期应为晋宁运动末期。矿体中黄铁矿同位素δ34S变化范围为-0.17^+7.41‰,平均值+1.9‰,其平均值接近陨石中δ34S=0±2‰的值,认为成矿流体中的硫来自下地壳或上地幔。王麻子沟金矿成因归属为变质-热液蚀变岩型金矿床。

The metallogenic material of Wangmazigou gold deposit derived from Mesoproterozoic erathem of the Dataishan Formation of Laoling Group and alkali feldspar granite of Yanshanian period. Mineralization had experienced multiple phases,and the four stages including： syndeposit period, deformation and metamorphism period, The magmatic hydrothermal alteration period, and supergenetic oxidation period. Pb-isotope of ore body ages of 743 Ma, suggesting the deformation and metamorphism period generated in late Tsinning movement. The δ34S values of pyrite range from-0.17‰ to ＋7.41 ‰,with an average of ＋1.9 ‰, The average sulfur isotopic characteristics of ore-forming fluids are similar to chondrite,indicating that the sulfur in the fluids was derived from deep-seated magma or the mantle. Those analyses provide important evidences of judging the ore genesis to the metamorphic-hydrothermal type.