陕西青山金矿床黄铁矿的标型特征研究及矿床成因探讨

Studies on typomorphic characteristics of the pyrite occurred in microdisseminated gold deposit of Qingshan,Shaanxi and discussion on its genesis

陕西青山微细浸染型金矿床中的主要矿石矿物黄铁矿具有标型意义,研究表明,富金矿段的黄铁矿具有颜色暗黄-灰黄、颗粒细小破碎、晶形差,为五角十二面体和复杂聚形、亏硫与铁的特点。矿区矿源层为含炭热水沉积岩层组成的黑色岩系,具有热水沉积成矿预富集-韧脆性构造叠加-大气降水为主的含矿热液改造的类卡林型金矿床的成矿特点,富金细粒黄铁矿是地下热卤水与大气降水热液两种流体混合与沸腾使物理化学条件瞬变的产物。

The pyrite has typomorphic significance, which is the main ore mineral of Qingshan micro-disseminated gold deposit in Shaanxi. The studies show that the gold-rich section is characterized by dark yellow- pale yellow, fine and broken grain, bad morphology, pentagonal dodecahedron and complicated combination, poverty in sulfur and iron. The ore source strata has its lithology as the black rock series that is composed of carbon-bearing hydrothermal sedimentary terrane, which has shown some metallogenic characteristics similar to Carlin-type gold deposit from the fact that it was formed in the process like hydrothermal sedimentary preenrichment -- ductile-brittle structural overlapping -- meteoric water dominated ore-bearing hydrothermal fluid alteration. Gold-rich fine pyrite is created by changing the physical and chemical conditions dramatically through mixing and boiling the underground hot brine and meteoric water hydrothermal fluid.