个旧-大厂地区地质构造演化及锡多金属成矿

个旧-大厂锡多金属矿床不是简单的燕山晚期地台环境的“花岗岩岩浆期后气液矿床”，矿区地处三大板块的交接部位附近的个旧-大厂锡矿，前泥盆纪区域构造岩浆活动及锡多金属成矿作用强烈，泥盆纪-三叠纪裂谷作用和锡多金属成矿特点突出。泥盆纪受北西向同沉积断裂控制，在南丹-河池一带裂谷作用明显，发生了海底喷流成矿，加上印支-燕山期构造岩浆改造，形成了大厂锡矿。三叠纪受北东向个旧-兴义-晴隆同沉积断裂控制，在个旧、兴义一带发生的裂谷作用，伴随基性火山成矿、喷流热水沉积成矿和燕山晚期花岗岩改造(叠加)成矿，从而形成了个旧锡矿。

GEOTECTONIC EVOLUTION AND TIN-POLYMETALLIC METALLOGENESIS IN GEJIU-DACHANG AREA

The Gejiu and Dachang tin-polymetallic deposits (the Gejiu and Dachang tin deposits in short) are both the most famous superlarge ones in the world. As to the genesis of the Gejiu and Danchang tin deposits, many hypotheses hold that they are granitic magmatism pneumato-hydatogenetic deposits formed in the platform circumstance during the Late Yanshanian. But in the past ten years, we have done much research work on basic geology and geological exploration in the Gejiu and Dachang mining districts and many new hypotheses have been put forward based on metallogenic studies: In the Gejiu and Dachang mining districts near the juncture of three plates, tin-polymetal mineralization and tectonic and magmatic activities during the Pre-Devonian were intensive. Tin-polymetallogenic and rift activities were eminent from Devonian to Triassic. In the Devonian, controlled by a NW-trending synsedimentary fault, rift activities were obvious and seafloor exhalative hydrothermal sedimentary ore deposition occurred from Nandan to Hechi. Then, superimposed by tectonic and magmatic activities from Indosinian to Yanshanian, the Dachang tin deposit was formed. In the Triassic period, controlled by the NE-trending synsedimentary Gejiu-Xingyi-Qinglong fault, rift activities from Gejiu to Xingyi were accompanied by basic volcano-sedimentary ore deposition, exhalative hydrothermal sedimentary ore deposition and granitic superimposed ore deposition during the Late Yanshanian, and the Gejiu tin deposit was formed.