| Shanyang-zhashui ore-concentrated area is located in Shanyang-zhashui basin in East Qinling orogenic belt, which tectonic attribution to the Qinling forearc basin system, experienced subduction-accretion orogeny in the Paleozoic and collision orogeny in the Mesozoic.The structure and magmatic activity of this area are strongly developed, with favorable metallogenic conditions.There are numerous porphyry ore deposit in this area.Lengshuigou Cu-Au deposit is kind of porphyry skarn deposit,which structure complex and study in low degree,have large range of mineralization, this paper choose Lengshuigou deposit as the research object. With field investigation, joint divided period coordination, fault geometry, kinematics and dynamics of research and analysis, microscopic structure analysis, We study the structural style, tectonic evolution, and the relationship between tectonics and metallogeny of this region in order to provide some reference and basis for the periphery prospecting in this mine area, furthermore, for the prospecting work of the similar ore in this region, the following understanding and results have been achieved:The dual structure: we found there was a angular unconformity between two strata in this mine area. This dual structure formed by the Proterozoic basement and late Paleozoic cover layer. The Proterozoic basement consists of diorite, granite and amphibolite schist, and the Paleozoic cover layer is mainly composed of limestone, silty mudstone, conglomerate. This dual structure indicated the area between late Proterozoic to Paleozoic had experienced a deflection and uplift process.Fault in three phases: with field investigation in this mine area, observation and analysis on geometry, kinematics, dynamic of faults’ characteristics and combined to joint divided period coordination of this mine area, we divided the fault into three phases: The first phase faults is the sinistral ductile shear fault, the second one is series brittle-ductile fault conjugate which striked NW and NE, the third one is series of brittle fault striked NW and SN.The relationship of structures and metallogenic:In this area, Cu Mo mineralization distribution are controlled by porphyry,the body of porphyry are controlled by the early tectonic weak zone such as the fault and the core of fold. Gold mineralization is controlled by ductile and brittle ductile faults in this area. The most closely relationship related to the ore mineralization is the second phase fault. Therefore, in the periphery prospecting work can focus on the second phase fault. |
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