锡铁山矿床中石膏、菱铁矿成因研究与意义

Genetic research of gypsum and siderite in Xitieshan deposit ant its significance

锡铁山矿床地表及上部中段的近矿围岩中发育大量的石膏和含锌菱铁矿,长期以来主要作为喷流沉积或后期改造的产物。同时,地表的褶皱构造在深部却不发育,其原因一直存在争议。在对这些石膏、含锌菱铁矿及相关地质现象研究的基础上指出,锡铁山矿床近地表部分存在强烈的氧化作用与岩溶作用,石膏、含锌菱铁矿的主体是大气降水条件下原生矿石氧化形成的,而非形成于喷流沉积作用。同时,强烈的岩溶塌陷改变了部分地质体的产状,这可能是形成地表矿体附近“褶皱构造”的主要原因。

It has been found that a lot of gypsum and zinc bearing siderite occur on the surface of Xitieshan deposit and near＂ ore country rocks of the upper part of the ore body. These minerals have long been recognized as a result of exhalation sediment. And, many folds only at the surface of the deposit, but haven＇t been found in lower part. The study of the minerals on geology suggests that very strong oxidation of the sulfide and karstification occurs on near sur^ace part of the Xitieshan deposit. The minerals formed from oxidation of the ore in the groundwater, but not the result of exhalation sediment. The karstification leads to breakdown and reforms the occurrence of some geological bodies, which probably is the main cause for the ＂fold＂ in the surface orebodies.