重磁场特征对西藏扎西康矿集区构造格架与成矿的启示

受印度-亚洲大陆碰撞造山作用的影响，扎西康矿集区内断裂构造发育，区内的铅锌多金属矿体赋存于下侏罗统日当组中，容矿围岩为含炭钙质板岩、钙质板岩和构造角砾岩，矿体严格受近南北向和北东断裂控制，呈脉状、透镜状产出。为了解扎西康矿集区构造情况及构造与成矿关系，笔者对开展的1：5万重磁测量获得的数据进行向上延拓，研究表明：矿集区具有反"L"异常分区特征，已知的矿床均处于低磁、低重区域，且深部存在多个隐伏岩体；再对数据进行水平方向导数、水平梯度模量和垂向二阶导数处理分析，解译出4条矿集区主断裂和1条次级断裂且该次级断裂为主要控矿断裂；主断裂或次级断裂圈闭区为成矿有利区，并划定4个成矿有利区；结合年代地质学、地球化学特征对构造格架与成矿进行了探讨，认为当具有一定构造格架时，则存在找矿潜力。

Enlightenment of the Characteristics of Gravity and Magnetic Field on the Tectonic Framework and Metallogenesis of the Zhaxikang Ore-Concentrating Area,Tibet

Affected by the collisional orogeny of Indian-Asian land-continent,the fracture structure developed in the Zhaxikang ore-concentrating area. The Pb-Zn polymetallic ore bodies in the area are occurred in the Lower Jurassic Ridang Formation. The vein-like and lenticular ore-bearing rock consists of carbonate-bearing slate, calcareous slate and tectonic breccias and the ore body is strictly controlled by the near N-S and N-E fractures. In order to understand the tectonic conditions and the relationships of the Zhaxikang ore area between tectonic and mineralization, the author processes the data obtained from the 1:50 000 gravity and magnetic measurement with upward extension, indicating that the ore-concentrating area has the anti-L abnormal partition feature and known deposits are in the low-magnetic and low-heavy areas, and there are many hidden rock masses in the deep. Then processes the data with horizontal derivative, horizontal gradient modulus and vertical second-order derivative,interpreting the four main faults in the ore-concentrating area and a secondary fault the fault is the main ore-control fault. It is proposed that the main fault or the secondary fault trap area is a favorable ore-forming area, and four ore-forming favorable areas are delineated, combined with chronological geology and geochemical characteristics discusses the relationships of the framework and mineralization. It is believed that when there is a certain structural framework, there is potential for prospecting.