东昆仑-南祁连富砷金矿与矿区岩浆岩的关系

RELATIONSHIP BETWEEN As-RICH GOLD DEPOSITS AND NEARBY IGNEOUS ROCKS FROM EAST KUNLUN TO SOUTH QILIAN MOUNTAINS

东昆仑五龙沟、柴北缘滩间山和南祁连黑刺沟等富砷金矿床一般均与矿区岩浆岩有关系。研究结果表明:空间上,矿化或发育于岩株的接触带上,或发育于闪长玢岩脉密集分布区,少数金矿化甚至发育于闪长玢岩隐爆角砾岩筒、岩脉中;时间上,金成矿与矿区岩浆岩的成岩时代接近,但前者稍晚;成分上,矿石中含量高的Au、As、Sb等成矿元素在矿区岩浆岩中含量同样较高。此外,金矿石和矿区岩浆岩的硫同位素、铅同位素、稀土元素、微量元素、氢氧同位素等均表明二者具有密切的成因联系。

Some Asrich gold deposits such as Wulonggou gold deposit in East Kunlun Mountains, Tanjianshan gold deposit on the northern margin of Chaidamu basin and Heicigou gold deposit in South Qilian Mountains are genetically related to the magmatites in their mining districts. Spatially, some gold mineralization occurs in the contact zones between igneous stocks and country rocks. While some other deposits are developed in the areas with intensive development of dioritic porphyrite dykes, and even within the dioritic porphyrite pipes and dykes. Gold mineralization is chronologically related to magmatites in their mining districts but the former is slightly late. The elements such as Au, As, Sb are of high content both in gold ore and in magmatites. S isotope, Pb isotope, REE, trace-elements, O isotope and H isotope of both gold ore and magmatites suggest that there are close relationship between gold mineralization and nearby igneous intrusives.