新疆西准噶尔布兰萨拉地区构造控矿规律

布兰萨拉地区地处新疆准噶尔盆地西北缘,位于谢米斯台—沙布尔提成矿带。研究区内金矿床与构造的关系密切,但是前人对构造的认识比较模糊,对构造的不同时间、不同类型、不同次序的研究不够深入；对构造格架体系的建立、分布规律以及其与成矿的关系还不明确。本文在翔实的野外地质研究基础上,对区内不同方向的构造进行梳理分级,明确断裂带与成矿的联系,研究构造控矿规律,建立构造成矿模式。区域上发育完整的三级构造系统:区域尺度为孟布拉克大断裂,是矿床的边界断裂；矿集区尺度为北东向韧性剪切带；第三级为剪切带内部或旁侧的同生或派生构造。研究区内金矿床成矿期主要有4个构造活动阶段:第一阶段为近东西向构造；第二阶段为北东向构造；第三阶段为近南北向构造；第四阶段为北西向构造。建立了成矿前区域构造走滑拉伸、成矿期扩张—挤压转换阶段热液运移成矿、成矿后断裂活化改造的三阶段构造控矿模式。

Structural ore controlling regularity in Bulansala area, West Junggar, Xinjiang

The Bulansala area is located in the northwest margin of the Zhungaer Basin in Xinjiang, and is situated in the Shemistai-Shaburti metallogenic belt. The gold deposits in the study area are closely related to structures, but the understanding of structures is rather vague, and the study of different time, types and order of structures is not deep enough, and the establishment of structure framework system, distribution law and its relationship with mineralization are not clear. In this paper, based on detailed field geological research, we sort out and classify the structures in different directions in the region, clarify the connection between the fracture zone and ore formation, study the structure control law, and establish the structure ore formation model:a complete three-level structure system is developed in the region, the regional scale is the Mengbulak Great Fault, which is the boundary fracture of the deposit; the scale of the ore set is the north-east ductile shear zone; the third level is the supporting structure inside or next to the shear zone or derived structures within or adjacent to the shear zone. There are four main stages of structure-activity during the metallogenic period of gold deposits in the study area:the first stage is near east-west structure; the second stage is north-east structure; the third stage is near north-south structure; the fourth stage is north-west structure. A three-stage structure control model of regional structure slip stretching before mineralization, hydrothermal transport and mineralization in the expansion-extrusion transition phase during mineralization, and fracture activation and transformation after mineralization has been established.