胶东郭城地区金矿床矿体定位机制研究及找矿方向

胶东郭城地区的金矿床地质特征与胶东其它地区的金矿存在较大的差异,其原因是该区发育了一组NE向深大断裂(可归为郯庐断裂派生的一组次级断裂),成矿期强烈频繁的构造-热事件导致形成了多组相互叠加的控矿构造,这种特殊的构造背景决定了该区矿体在形态、产状和赋存特征方面的特殊性。通过对矿山大量探采工程所揭露的控矿构造的研究发现,矿体定位于郯庐断裂(Ⅰ)的次级断裂带(Ⅱ)所派生出的NEE、NNE及NW向3组更次级结构面(Ⅲ)中。通过研究这3组结构面成生的力学性质和空间组合特性,揭示矿体的定位机制并指出该区下一步的找矿方向。

Gold orebody location mechanism and prospecting direction in Guocheng area, Jiaodong Peninsula

The geological characteristics of gold deposits in Guocheng area are quite different to those of other deposits in Jiaodong Peninsula. Their features of shape, attitude and occurrence of orebodies, are due to a special tectonic background. Guoeheng area developed a series of NE trending deep faults, resulted from the extensional strike - slip movement of the Tan-Lu fault system in the Early Cretaceous. As a result, intensive teetonic-hydrothermal events during gold ore formation leaded to form multi-superposed structures. Based on extensive investigation on ore-controlling structures revealed by underground workings, it was proposed that the orebodies were located in NEE, NNE and NW fractures （ Ⅲ ） secondary to the Guocheng fault zone （ Ⅱ ）, which belongs to the Tan-Lu fault belt （ Ⅰ ）. The main aims of this paper are to investigate the mechanical properties and spatial combination rules of these three orebearing fractures, reveal orebody location mechanism, and the propose prospecting direction in future.