北京万庄岩溶型金矿的构造特征与隐伏矿床预测

THE TECTONIC FEATURES AND HIDDEN ORE PREDICTION OF WANZHUANG KARST-TYPE Au MINERALIZATION IN BEIJING CITY

万庄金矿属岩溶型金矿床，其控矿构造有古岩溶和断裂．早（Ⅱ，Ⅷ号）、晚（Ⅲ号）两期岩溶分别发育于中元古界长城系团山子组第３、４段与大洪峪组第３段厚层白云岩中，其上及附近发育有与岩溶贯通的张性控矿断裂（Ⅵ、Ⅶ号）。根据岩溶的发育规律、含矿张性断裂与含矿石英脉的构造形迹及物探资料等分析后认为，两层岩溶将继续向西南端延伸．矿区南部是寻找岩溶型金矿的最有望地段．

The Wanzhuang gold deposit is of the karst-type. The ore-control structures are paleokarst and fault. The two early (No.Ⅱ and Ⅷ) and late(No.Ⅲ)are developed respectively in the thick-layer dolomites of the third to the forth members in Tuanshanzi Formation and the third member in Dahongyu Formation of Changcheng System in Mid-Proterozoic Group, and over or near the karsts there are devoleped the tensional ore-control fractures such as number No.Ⅵ and No.Ⅶ running through the karsts.According to analysis on the forming law of karsts, the structural features of ore-bearing tensional fractures and ore-bearing quartz veins and geophysical prospecting data and so on, the south-west terminals of the two layers of karsts should be prolonged ahead. Therefore, tile south part of the ore area will be the best prospective section seeking for the karst-type Au ore deposit.