Fracture Characteristics And Evolution On The Zhaoyuan And Bengbu Part Of The Tan-Lu Fault Belt

Tan-Lu fault belt is an important intense tectonic deformation zone in eastern China,it is also a huge lithospheric fault system with different characteristics at different timesand different locations in the long-term activities. Accompanied by faulting, produced alarge number of volcanic-magmatic activities and formed a large-scale NE-trendinggold mineralization belt in eastern china.ZhaoYuan and BengBu area studied in this paper are located on both sides of theTan-Lu fault belt, The former is China’s most important gold ore district, Many oversizeand large gold mines are outputed in the NE and NNE-trending fault or flankings in thisarea. In particular, ZhaoPing and JiaoJia fault belt control and development of manygold deposits. Studies have shown that, both of the ZhaoPing and JiaoJia fault belt haveexperienced the early ductile deformation and the late brittle deformation, the latterphenomenon is superimposed on the transformation of the former is obvious. The latebrittle deformation performanced of tenso shear and compresso shear two processes, thetenso shear movement provides host space for ore body, While the lately compressoshear movement damaged to the orebody. With the fault activities led to the formationof two types of gold deposits:the fracture zone altered rock type and gold-bearing quartzveins, two types of gold deposits are obviously controlled by faults, especially in NNEand NE-trending fault to master. NNE-trending faults not only provides the ore fluids agood channel, but also providing a host space for the ore bodies.WuHe area and JiaoDong gold belt has the same tectonic background, Metallogenicgeological conditions and structural is very similar.NNE and nearly NS-trending faultsas the part of the Tan-Lu fault belt in the region, development of large-scale,Stronglydeformed,its main fault that ZhuDing-ShiMenShan fault, the field can see both ductiledeformation and brittle deformation. Ductile deformation is mainly developed in themylonite in the Wuhe group, shows a typical strike-slip characteristics of the ductileshear zone. And brittle deformation in the fault zone appears cataclastic rock, faultbreccia and fault gouge, the extruded schistosity, cleavage and tectonic lens is verydeveloped.Through comparative analysis, Tan-Lu fault belt on the Wuhe part has gonethrough three major development stages:The first movement period corresponded to theLate Jurassic to Early Cretaceous, characterized by left-lateral strike-slip ductile shearzone. The second movement period corresponded to the Early Cretaceous to Paleogene,with brittleness extensional Normal faults. The third movement period corresponded Neogene to now,with squeeze thrusting faults. NNE and nearly NS-trending faults isalso the main ore-controling and ore-bearing faults. Along both sides of the faults orsecondary faults(low-order sub faults)developed a good gold mineralization, its also themain ore-controlling and ore-bearing faults in this area. The major types ofmineralization in this area is gold-bearing quartz veins, followed by the structuralfracture zone altered rock type.