东秦岭杨斜-丰北河成矿带杨屋场钨(金)矿床地质特征及成因探讨

杨屋场小型钨（金）矿床位于东秦岭杨斜-丰北河金钨成矿带东段。通过野外调查、岩矿鉴定及综合研究，查明了该矿床的地质特征与控矿因素，探讨了矿床成因，初步建立其“三位一体”找矿预测模型，可为杨斜地区钨金找矿提供一定的借鉴。研究表明，矿体赋存于商丹断裂带内北东—北北东走向的缓倾断裂，围岩为新元古代杨斜片麻岩套。矿石金属矿物为黄铁矿、黑钨矿、白钨矿、黄铜矿、闪锌矿、方铅矿及黝铜矿等中-高温组合。成矿过程包括热液成矿期与表生期，前者可划分为石英-细粒黄铁矿、石英-黑钨矿-白钨矿-多金属硫化物和石英-方解石-绢云母3个成矿阶段，围岩蚀变以硅化、黄铁矿化和白云母化为主。矿床的成矿作用受印支期花岗岩、断裂构造及围岩控制，成因应属于岩浆期后热液矿床。

On the Geological Characteristics and Genesis of Yangwuchang Tungsten (Gold) Deposit in the Yangxie-Fengbeihe Metallogenetic Belt,East Qinling

The Yangwuchang tungsten (gold) deposit is located in the eastern part of the Yangxie-Fengbeihe gold-tungsten metallogenetic belt, east Qinling. Through field survey, ore identification and comprehensive studies, this paper clarified the geological characteristics and ore-controlling factors of the deposit, discussed genesis of ore deposit, and preliminarily established the trinity prospecting prediction model, which provides a direction for further W-Au prospecting in Yangxie area. The results show that the ore bodies occur in the NE-NEE faults in the Shangdanfault zone, and are hosted in the Neoproterozoic Yangxie gneiss suite. The metal minerals are medium-high temperature mineral assemblages of pyrite, wolframite, scheelite, chalcopyrite, sphalerite, galena and tetrahedrite. Ore-forming process includes hydrothermal mineralization and supergene periods. The former can be divided into three metallogenic stages: quartz-fine-grained pyrite stage, quartz-wolframite-scheelite-polymetallic sulfide stage and quartz-calcite-sericite stage. Wall-rock alteration is mainly silicification, pyritization and muscovitization. The genesis of this deposit is considered to be a post-magmatic hydrothermal deposit, controlled by the Indosinian granite, faults and wall rock.