上明峪金矿地质特征及其与大河南岩体的关系

GEOLOGICAL CHARACTERISTICS OF THE SHANGMINGYU GOLD DEPOSIT AND ITS RELATIONSHIP TO DAHENAN GRANITE MASS

太行山北部的大河南岩体内部分布有一些金矿床及大量金矿化点，其中最具代表性的是上明峪金矿。大河南岩体侵位之后，遭受了强烈的构造运动，形成了近ＳＮ向和近ＥＷ向的两组断裂构造，断裂构造的活动使岩石强烈破碎形成破碎蚀变岩，岩浆热液萃取了花岗岩中的成矿元素并将其搬运至断裂带内，这种富含成矿元素的岩浆热液在断裂带中与天水混合，导致热液中的成矿元素沉淀形成矿化。

Dahenan granite mass with an outcrop area of about 900 Km 2 is located in the northern part of Taihang Mountains. There are some gold deposits and many gold mineralized sites distributed in Dahenan granite mass. The authors have studied the recently discovered Shangmingyu gold deposit in this rock mass, which can serve as an example of gold deposits in this area. This paper deals with the geological characteristics of the Shangmingyu gold deposit and its relationship to Dahenan granite mass. Dahenan granite mass has experienced severe structural deformation and formed nearly NS and EW trending faults, which are filled with veins. The movement of the faults caused the strong shattering of the rocks and hence formed broken rock belts. During this process, magmatic hydrothermal fluid absorbed such ore forming elements as Au, Cu, Ag, Pb and Zn from the surrounding rocks it flowed through and became ore forming fluid. These ore forming elements were precipitated in the broken rocks and formed the orebody. Magmatic fluid absorbed ore forming elements from its surrounding rocks and transported them to the faults, reacted with meteoric water, and precipitated these elements. The circulating movement of the ore forming fluid in the fault system and its mixture with the meteoric water resulted in the stronger concentration of the ore forming elements and finally formed the high grade orebody. The Shangmingyu gold deposit resulted from the reaction between magmatic fluid and meteoric water.