青海省石藏寺金锑矿床地质特征及成矿机理探讨

石藏寺金锑矿床位于泛华夏大陆晚古生代藏北(羌塘)三江弧前盆地,西倾山晚古生代盆地西端北缘。矿床为金锑矿共生矿床,其矿体受构造破碎带控制,呈似板状、透镜状。自然金主要与辉锑矿、石英嵌布关系密切,辉锑矿中包裹金占50%以上,粒间金、裂隙金与辉锑矿、石英连生。围岩蚀变有硅化、绢云母化、黄铁矿化、褐铁矿化。石藏寺金锑矿床与临区大场金锑矿床类似。矿床形成机理为在青藏高原碰撞造山带过程中,岩浆热液沿着深大断裂迁移,并与大气水发生循环,从围岩中断萃取Au,Sb矿物质,在构造、地球物理化学条件适宜的部位聚集形成金锑矿体,为造山型金锑矿床的浅成矿床。

Geological Characteristics and Metallogenic Mechanism of Shizangsi Gold-antimony Deposit in Qinghai Province

Shizangsi gold-antimony deposit located in Sanjiang arc basin in northern Tibet (Qiangtang) of mainland China in late Paleozoic and western end and northern margin of Xiqingshan mountain in late Paleozoic basin. This deposit is symbiosis of gold and antimony. The ore bodies were controlled by tectonic fractural belt with similar plate and lenticular types. Native gold has close relation with stibnite and quartz. Gold inclusions accounted for 50% or more. Intergranular gold and fissured gold have paragenetic relation with stibnite and quartz. The alteration of country rocks were composed of silicification, sericitization, pyritization and limonitization. Shizangsi gold-antimony deposit is similar with Dachang gold-antimony deposit. In the period of forming Tibetan collision orogenic belt, magmatic hydrothermal migrated along the deep faults, happened atmospheric water cycle, extracted Au and Sb minerals, and accumulated gold-antimony ore bodies in the areas with appropriate geophysical and geochemical conditions. It was the shallow deposits of orogenic gold and antimony deposits.