碳酸盐岩中沉积改造金属矿床的成矿流体性质及成矿、改造深度问题

The Property of Mineralizing Fluid and the Depths of Mineralization and Reformation of Metal Deposits Reformed by Sedimentation in Carbonate Rocks

我国碳酸盐岩中沉积改造金属矿床的成矿、改造深度及流体性质等同题,目前仍有不同的意见,作者根据我国铅锌、汞、锑的包裹体水的氢、氧同位素组成,它们的共生矿物,菱铁矿的碳、氧同位素组成,成矿温度,化学成分等认为成矿流体是大气降水,不是卤水。根据水文地质特征,结合一些沉积改造矿床垂直分带现象认为成矿、改造的深度都在地下水潜水面以下200—300m以内的还原成矿带中,其以下是地下水停滞带,只有分散的金属元素或其络合物,或品位低,杂质多的原生沉积矿层(菱铁矿)。

There are still different opinions about the property of mineralization and reformation fluid of metal deposits reformed by sedimentation in carbonate rocks in China. According to the isotopic composition of carbon and oxygen of inclusion water of Pb, Zn, Hg and Sb in China, their associated minerals, and the isotopic composition of carbon and oxygen, mineralization temperature and chemical composition of siderite, the writer thinks that the mineralization fluid is atmospheric precipitation, not brine. According to hydrogeological features, togather with vertical zoning phenomena of some sedimentary reformed deposits, the writer believes that the depths of mineralization and reformation are within a reduction mineralization zone of 200 -300m below the groundwater table. Below the zone is a stagnant groundwater zone where there are only scattered metal elements or their complex or original sedimentary ore beds (siderite) which have lower tenors and more impuri ties.