桂西北盆-山构造系与大厂锡石多金属成矿作用

A BASIN-AND-RANGE TECTONIC SYSTEM IN NORTHWEST GUANGXI, CHINA, AND THE DACHANG TIN-POLYMETALLIC MINERALIZATION

通过对区域地形形态、地质构造格架、大厂矿田的矿床地质、地球化学特征的研究，阐明了大厂矿区所处的构造位置为一盆-山构造系。大厂锡石多金属硫化物矿床的生成、发展和演化是该盆一山构造系发展演化的产物，受盆-山构造系的控制。本矿床按矿体形态、矿床特征可以分为层状矿化和脉状矿化两大类。层状矿化是盆-山构造系形成早期同生沉积的，严格受地层层位和岩性的控制。脉状矿化是盆-山构造系发展演化的晚期不同阶段中受岩浆热液作用的叠加、改造而成，受构造和层位的双重控制。

The paper studies the original geography, tectonic framework, geology and geochemisry of the Dachang tin-polymetallic ore field. The ore field is located in a basin-and-range tectonic system. Formation, development and evolution of the ore deposits are mainly controlled by the basin-and-range tectonic system.According to ore body topography and mineralization features, the ore deposits can be divided into 2 mineralization types, stratiform and vein types. The stratiform mineralization which is controlled by stratigraphic sequence and lithology can be formed by sedimentation in the early stage of the basin-and-range system, and the vein mineralization which is controlled by both the fault and stratigraphic sequence can be due to magmatic hydrothermal overprint and reformation for primary mineralizational strata.