西藏马扎拉金矿区外围地质特征与找矿方向

马扎拉金矿位于藏南拆离断裂以北的特提斯喜马拉雅南部隆子逆冲推覆断裂南缘,是扎西康整装勘查区构造蚀变岩型金矿床的典型代表。本文在矿区外围30km2范围开展地质测量工作,重新厘定了矿区及外围的地层系统并新发现大量岩浆岩,重塑了矿区及外围的断裂构造格架并初步厘定了构造活动期次,结合地球物理剖面测量、区域地质新近调查研究成果和少量工程验证,初步构建了矿床的控矿构造几何模型并重新确立了矿区及外围在近东西向具有早期逆冲推覆、晚期伸展滑脱的前断坡和反冲断裂及其次级断裂中寻找构造蚀变岩型金矿的找矿方向,对进一步找矿工作的部署具有重要的指导意义。

Geology and exploration potential of the Mazhala gold deposit,Cuomei, Xizang: An approach

The Mazhala gold deposit as an earliest discovered gold deposit in the Zhaxikang mining district is located on the southern margin of the Lungzi thrust in the southern part of Tethyan Himalaya,north of the south Tibetan detachment fault system. A geological mapping within the extent of 30 km² is currently carried out in the Mazhala gold deposit and its adjacent area in this study. The stratigraphic system in the mining district is redefined, and widespread magmatic rocks has newly been recognized. The fault framework is reshaped,and the deformation stages in the mining district are preliminarily determined. According to the regional geological characteristics and recent findings in the geological survey,and geophysical and geochemical anomalies,a new model for orecontrolling structures is tentatively constructed. Further exploration of this gold deposit should be focused on the EW-trending faults and their secondary fractures within the overthrust system. These faults are ramps and backthrusts. They are extruded in the early stages and extended in the later periods. The emphasis should be placed on the structural alteration type gold deposit in these structures. The results in this study may have important significance for the deployment and arrangement in the future exploration of the Mazhala gold deposit.