摘要
潼峪金矿区发育过冲剪滑型、平移剪张型和平移剪滑型三种不同性质、不同方向成矿断裂,分布在金罗斑背形的不同部位,其形成有先后差异,但变形环境大体相同,具脆-韧性变形特征。空间上一般不超越褶皱主体。三类断裂中,前两者具石英脉型金矿化,后者形成构造蚀变岩型及小规模石英脉型金矿化。矿化差异与断裂产出的褶皱部位及其相应的应力应变条件的不同有关。
There are three types of metallogenic fractures in Tongyu gold mine which is situated in the west part of Xiaoqinling ore belt. They are thrust shear-slip, strike t-enso-shear slip and strike shear-slip. The attitude and the machanical properties of these fractures are different. The thrust shear-slip fracture parallel to the foliation ( S2 ) is located in the limb of fold ( F3).The multiphase thrust shearing resulted in the formation of quartz veins infour periods. The thickness of the fractures changed with the depth indicates the pattern of the space extension during folding periods. The strike teaso-shear slip fractures occur in the core of the fold ( F3 ), crossing foliation ( S2) , The space extension is short and wide with the tenso-shear deformation. The orebody of the rein bearing-gold in the ore area is located in the both former types. The strike shear-slip fractures cross the limb and the core of the fold (F3), Its deformation in.dicates the strike-slip shearing.It is longer than the other types. The Ss-Sc fabric can grow up. The space extension in this fracture is not good because of strong compression.The major orebody is the alteration-rock-bearing gold.
The three types of metallogenic fractures are formed in the mid depth of the structural level.And their structural deformation environ,ments are similar to each oth-er (300°~500°; 0.3-0.8GPa; 3.8~10km) . They belong to the ductile-brittle deformation.
The metallogenic fractures and the fold ( F3) belong to a structural system. Both of them developed during the mid period of structural deformation in this area. The former is controlled by the local stress of the fold ( F3) .It is also the major reason of the three types of fractures. There is a uniform law from folding to fracturing and ore control.
关键词
金矿床
成矿
断裂构造
Tongyu, fold ( F3), metallogenic fracture, ductile-brittle deformation
