河南省桐柏县老湾金矿带断裂特征及控矿模式

Fracture characteristics and ore-controlling model of Laowan gold deposit,Tongbai county,Henan Province

老湾金矿带受控于区域性龟(山)-梅(山)断裂在桐柏的出露部分——老湾脆-韧性剪切带。老湾脆-韧性剪切带为一右形走滑剪切断裂系统,它包括矿带南北两侧的边界断裂——老湾和松扒断裂及它们之间的次级剪切裂隙。老湾和松扒断裂为右形走滑性质的导岩、控岩断裂,它控制了区内岩浆热液产生和热液成矿体系的形成;次级剪切断裂位于两边界断裂之间的一系列次级脆性断裂,它们因几何形态、构造特征、滑移方式等方面的不同而具有分段性。其中上上河-彭家老庄段属区域右行走滑体系中R型张扭性断裂,老湾-盛老庄段主要为P型压扭性,其次为Y型张扭和T型张裂隙,二者同为Riedel剪切裂隙系统,组成一个由P和R连结的辫状右行走滑剪切带,它控制着老湾金矿带所有的矿脉带和矿(化)体。因而老湾金矿带断裂构造控矿模式为:一级边界断裂控岩,次级右行走滑剪切断裂带控矿.

Laowan gold ore zone is controlled by Laowan brittle-ductlie shear zone which is a part of Guis- han-Meishan fault that uncovered at Tongbai area. Laowan brittle-ductile shear zone is a kind of right-slid- ing-shear rupture system, which including Laowan-Songba fault and a type of secondary shear fracture. Laowan fault and Songba fault are right sliding rock and ore-controlling fault, which control magmatic hydrothermalism and hydrothermal minerogenetic system engender at this area. The secondary fault lie in some brittle faults that in two border fault, which are different because of geometric shapes, structure features and sliping styles. Shang- shanghe-Pengjialaozhuang ore block is a R-tensile contorted fault that is a type of regional right sliding system. Most of Laowan-Shenglaozhuang ore block are P-compressible contorted fault, the others are Y-tensile contorted fault and T- tensile fracture, they are Riedel-shear system and made up a type of braided right sliping shear zone that contacted by P-shear zone and R-shear zone, which controls all lodes and mineralized bodies in Laowan gold deposit. So the ore-control model of fault structure in Laowan gold deposit is primary border fault control wall rocks and secondary right-sliping-shear fault zone control ores.