个旧锡矿区域地壳演化与成矿探讨

REGIONAL CRUST EVOLUTION AND METALLOGENESIS OF GEJIU TIN DEPOSIT—A DISCUSSION

个旧锡多金属矿床是驰名中外的特大型矿床,过去认为是燕山晚期"花岗岩岩浆期后气液矿床"。但通过探讨区域上前震旦纪地壳演化、震旦纪—早古生代地壳演化、泥盆纪—三叠纪地壳演化以及侏罗纪—第四纪地壳演化,以及与成矿之间的关系,发现个旧矿区至少经历了印支中晚期海底基性火山—沉积成矿、印支中晚期海底喷流热水沉积成矿、燕山晚期花岗岩叠加改造成矿以及喜山期陆相表生沉积成矿作用,厘定了个旧锡矿区的印支中晚期海底基性火山 沉积Sn Cu Zn(Au)矿床系列、印支中晚期海底喷流 沉积Sn Cu Pb Zn矿床系列、燕山晚期花岗岩叠加改造Sn Cu W Be Bi Pb Zn Ag矿床系列、喜山期陆相表生沉积砂矿矿床系列等4大矿床系列及12种矿床类型。

The Gejiu tin deposit is the most famous superlarge deposit in the world. As to its genesis, many researchers advocate the viewpoint that the deposit is a granitic magmatism pneumato-hydatogenetic deposit formed during the Late Yanshanian. As viewed from the relationship between the regional evolution of Pre-Sinian, Sinian to Early Palaeozoic, Devonian to Triassic, Jurassic to Quaternary, and metallogenesis, the authors found that in the Gejiu diggings, there occurred seafloor basic volcano-sedimentary mineralization, seafloor exhalative hydrothermal sedimentary mineralization of the Middle-Late Indo-Chinese epoch and terrestrial weathering sedimentary mineralization of the Himalayan epoch in addition to granitic superimposed mineralization of Late Yanshanian. And four deposit metallogenic series in the Gejiu diggings such as seafloor basic volcano-sedimentary Sn-Cu-Zn (Au) deposit series of the Middle-Late Indo-Chinese epoch, seafloor exhalative hydrothermal sedimentary Sn-Cu-Pb-Zn deposit series of the Middle-Late Indo-Chinese epoch, granitic superimposed Sn-Cu-W-Be-Bi-Pb-Zn-Ag deposit series of the Late Yanshanian epoch, and twelve deposit types are defined. So a new metallogenic theory has been established and the prospecting orientation is pointed out.