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通过对拾金坡岩体宏观地质特征、岩石矿物学、岩石化学以及地球化学成果的全面分析,通过对区域成矿地质背景的研究,总结了该区金矿的控制因素。区内金成矿主要受岩体和构造控制。岩体是成矿的最主要因素,矿化与岩体有密切的时空关系,区内大多数金矿床产在拾金坡岩体的边缘。拾金坡复式花岗岩由早期到晚期可分出闪长岩、似斑状二长花岗岩和黑云母二长花岗岩共3期岩浆活动。岩石学和地球化学研究表明该岩体为下地壳或上地幔源,属Ⅰ型或同熔型;岩体相对富集轻稀土,δEu值为0.45～0.99。加里东晚期似斑状二长花岗岩提供了成矿物质,海西早期钾长花岗岩对含矿热液的运移起到了积极作用。处于深处的钾长花岗岩在上升过程中产生了含矿热液,并且在似斑状花岗岩中形成了一系列断层,这些断层为成矿流体的运移和富集提供了空间。海西期的构造岩浆活动不但为含金热液在二长花岗岩中的上升运移开辟了通道,而且为金矿化提供了热源,在似斑状二长花岗岩中形成石英脉型金矿床。
Based on a comprehensive analysis of macroscopic geologic features, rock mineralogy, petrochemistry and geochemical achievements of the Shijinpo rock mass, the controlling factors of gold deposits in this area are summarized through the study on the geological background of the metallogenic region. Gold mineralization in the area is mainly controlled by the rock mass and structure. Rock mass is the most important factor of mineralization. Mineralization and rock mass have close temporal and spatial relationship. Most of the gold deposits in the area are located at the edge of the Zijinpo rock mass. From early to late, the Shijinpo composite granite can be divided into three types of magmatism: dioritic porphyritic monzonitic granite and biotite monzogranite. Petrological and geochemical studies show that the rock mass is of the lower crust or upper mantle origin and belongs to the type I or the same type of melt. The rock mass is relatively enriched in light rare earth with a δEu value of 0.45-0.99. Late Caledonian porphyritic monzonitic granites provide ore-forming materials. Early Hercynian K-long granites played a positive role in the migration of ore-bearing hydrothermal fluids. Potash-bearing granites in the depths produced mineralized hydrothermal fluids during the ascent, and formed a series of faults in plagioclase-like granites. These faults provide space for the migration and enrichment of ore-forming fluids. The Hercynian tectonomagnetism not only opened up a channel for the ascending and descending of gold-bearing hydrothermal fluids in the gneissic granites, but also provided a heat source for gold mineralization and formed quartz vein-type gold deposits in plagioclase-like granite.