甘肃省文县牛圈山金矿地质特征

Geological Characteristics of Niuquanshan Gold Deposit, Wenxian, Gansu

工作区位于南秦岭印支褶皱带南部,扬子地块西北缘,地质上被誉为“金三角”地带。区域内出露地层以泥盆系、元古界为主,次为少量震旦系-寒武系、石炭系、二叠系、三迭系、侏罗系等牛圈山金锌矿化点位于碧口群北缘,联合村-新关-阳山和康县-略阳-勉县金成矿带之间,北临文县阳山超大型金矿床,东临武都区田家沟小型金矿床;赋矿地层为泥盆系中统三河口组第一-二岩性段,含矿岩石有泥钙质板岩、断层角砾岩,金矿化体主要受北东向断层控制,断裂带宽0.2~200.0m,与矿化关系较密切的围岩蚀变有黄铁矿化、褐铁矿化、孔雀石、硅化和铁碳酸岩化等。牛圈山金锌矿化明显受断裂-裂隙系统控制,层间断裂、蚀变对金成矿较有利。目前认为牛圈山金锌矿化属于构造蚀变岩型。

The working area is located in the south of the Indosinian fold belt of the South Qinling Mountains and the northwest margin of the Yangzi massif. It is geologically known as the “Golden Triangle” zone. The outcropped strata are mainly Devonian and Proterozoic, followed by a small number of Sinian-Cambrian, Carboniferous, Permian, Triassic and Jurassic Niuquanshan gold and zinc mineralization sites located in the northern edge of Bikou Group, between Liancun-Xinguan-Yangshan and Kangxian-Lueyang-Mianxian gold metallogenic belt, and Yangshan super large gold deposit in Linwen County, North China. Tianjiagou small-scale gold deposit in the east of Wudu area;the ore-hosting strata are the first-second lithologic section of the Sanhekou Formation in the middle Devonian. The ore-bearing rocks are argillaceous slate and fault breccia. The gold mineralization bodies are mainly controlled by NE-trending faults with a fracture bandwidth of 0.2~200.0 m. The wall rock alterations closely related to mineralization are pyritization and limonite. Mineralization, malachite, silicification and iron carbonation.Niuquanshan gold-zinc mineralization is obviously controlled by fracture-fissure system. Interlayer faults and alterations are more favorable for gold mineralization.It is thought that Niuquanshan gold-zinc mineralization belongs to structural altered rock type.