加甘滩金矿床地质特征及矿床成因初探

加甘滩金矿床位于西秦岭造山带西南缘,是西秦岭西段近年来勘查发现的大型金矿床之一。矿体主要呈脉状、板状、透镜状赋存于下三叠统隆务河组长石石英变砂岩、粉砂质板岩内,并受NW向断裂构造控制。金矿化与硅化、赤(褐)铁矿化、碳酸盐化、毒砂化及辉锑矿化等关系密切。通过对区域地质成矿背景、矿床地质特征、矿石矿物蚀变组合特征等成矿地质条件的分析认为,成矿具有多阶段性,成矿热液具多期性,矿床成因类型属中低温构造蚀变岩型。

Geological characteristics of Jiagantan Gold Deposit and preliminary discussion about its genesis

Jiagantan Gold Deposit lies in the southwestern part of West Qinling Orogenic Belt and is one of the large scale gold deposits discovered in the area in recent years. The orebodies mainly take the form of veins,plates and lens,occurring in feldspar quartz metamorphic sandstones and sandy slates of lower Triassic Longwuhe group,and are mainly controlled by NW trending fracture. Gold mineralization is closely associated with silicification,hermatitization ( ferritization) ,carbonation,arsenopyritization and stibnitization. The paper analyzes the geological settings of minerali-zation,the geological features of deposits and the combination of mineral alteration,and concludes that the deposit be-longs to a medium low temperature tectonic alteration rock deposit with multi-stage mineralization and multi-phase ore-forming fluids.