内蒙古常福龙剪切带型金矿床形成的构造控制

Structural control on the formation of Changfulong shear zone-hosted gold deposit,Inner Mongolia

内蒙古常福龙金矿床位于华北地台北缘中段区域EW向韧性断裂的次级NWW剪切带系统内。金成矿发生在燕山晚期,处于区域构造体制挤压-伸展-挤压的转换期以及2期近南北向大规模构造推覆作用的间歇期,张性构造环境为剪切带流体汇聚与成矿作用创造了条件。剪切带构造控矿主要表现为主断裂构造透镜体控矿、主断裂局部张性部位控矿和次级张性断裂-裂隙控矿3种基本型式,构造-流体共同作用分别形成了蚀变岩型、角砾岩型和石英脉型矿化(体),形成了常福龙剪切带型金矿床构造-蚀变网络基本格局。可以考虑利用构造-蚀变网络结构上的自相似性,指导矿山深边部找矿勘查以及剪切带系统内新矿体的预测。

Changfulong Gold Deposit in Inner Mongolia is hosted in the secondary NWW trending shear zone system of the regional EW trending ductile fault locating at the middle of the north part North China Craton. Gold mineralization occurred in Yanshanian. It is a time that regional tectonic regime transited from compression to extension and to compression,and a period just between the large scale of regional thrusts in this area. Tensile tectonic environment supplied the possible conditions for ore fluids concentration and related mineralization in the shear zone. Ore types in the structural ore-controlling shear zone can be classified into the main fault tectonic lens controlling types,the main fault local tensile fracture controlling types and the secondary tensile fracture-fissures controlling types. Coupling of structural deformation and fluid flow in the shear zone formed the different ore mineralization of altered rocks type,breccias type and quartz vein type,which established the basic pattern of structure-alteration network of the orehosting shear zone. It＇s a good guide to use the self-similarity characteristics of the structure-alteration network for prospecting in the deep part and edge of the mine and find new ore bodies.