石泉-汉阴北部下志留统梅子垭组黑色岩系金矿带位于南秦岭造山带西部的牛山古陆北缘.该矿带东西长约100 km,南北宽10-20 km.初步查明下志留统梅子垭组为区内金矿含矿层位,并按其岩性组合特征划分为6个岩性段,4个子含矿层位.矿带内发现10余处金矿床(点).金矿受地层、岩性、古地理和古构造条件控制,与黑色岩系具有同源性.金主要以颗粒金存在且分布极不均匀.硫同位素的变化范围说明硫来源于地层.氢氧同位素的特征说明成矿热液中的水介质是以变质热液和大气降水为主的混合水.稀土元素特征显示金矿物源与秦巴地区泥盆系沉积岩相似.韧性剪切带并不是金矿体出现的必须标志.研究认为梅子垭组中的金矿属沉积型矿床.%The gold deposit belt of black rock series of Lower Silurian Meiziya Formation in Northern Shiquan-Hanyin is tectonically located in the north margin of Niushan Old Land in the west of South Qinling Orogenic Belt. The ore belt is about 100 km long in E-W direction and 10-50 km wide in S-N direction. The early exploration has ascertained that the Lower Silurian Meiziya Formation was the ore-bearing layer of the gold deposits in this region. Based on the lithological assemblage characteristics, it is divided into six lithologic members and four ore-bearing sub-layers. More than ten gold deposits have been found in this ore belt. The gold deposits in this belt, controlled by stratigraphic, lithologic, paleogeographic and paleo-structural conditions, are homologous with the black rock series. The gold occurs mainly in particles and is unevenly distributed. The isotopic data show that the sulfur was originated from the strata. The characteristics of hydrogen and oxygen isotopes indicate that the aqueous media of the ore-forming fluid are mixed water containing mainly metamorphic-hydrothermal solution and atmospheric precipitation. The REE features reveal that the material source of gold deposits is similar to the Devonian sedimentary rocks in Qinba area. Ductile shear zone is not the necessary indicator for the existence of gold orebodies. Therefore, the gold ore in Meiziya Formation is a kind of sedimentary deposit.
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