Tectonic Deformation Characteristics Of Luanchuan Huangbeiling-Shibaogou Area In East Qinling Orogen

The Eastern Qinling Orogen molybdenum polymetallic metallogenic belt is located at the junction of the southern margin of the North China block and the Qinling Orogen microplate,and it is also the major component of the Qinling-Qilian-Kunlun Central Orogenic belt.There are more than 50 different-sized molybdenum polymetallic deposits and occurrences,the molybdenum reserves occupy a favorable position at home and abroad,Luanchuan ore concentration area is located in the East Qinling Orogen metallogenic core parts.In recent years,Huangbeiling-Shibaogou is the area with great progress in exploration work in Luanchuan ore concentration area,the characteristics of the exposed middle acid small rock mass in Yanshanian Period are similar to those in the ore concentration area,the location of the collision orogenic belt makes the structure complex and diverse,and is closely related to mineralization.However,the early research on the structure of this area is still deficient.Therefore,this paper takes advantage of the regional analogy method,compared with the results of stereographic projection analysis of geological elements and field structures in the study area and ore concentration area to research Huangbeiling-Shibaogou area tectonic deformation characteristics,associate with regional geological evolution,obtain the tectonic evolution history of the study area,and offer the basis for looking for hidden deposits in this area.On the premise that the field structural features distribution in ore concentration area shares the similar trend in study area,combined with polar stereographic projection analysis results of the Luanchuan ore zone and Huangbeiling-Shibaogou area geological occurrence data,the tectonic evolution of the study area is divided into two periods:?.By comparing with the stereographic projection results of Luanchuan ore concentration area range 9 and Huangbeiling-Shibaogou range 6 sections strata occurrence data,the strata deformation characteristics of the projection pole distribution are similar,and so dose the strata deformation stress state is also similar.According to regional geological evolution history,it is a large-scale thrusting system formed by the compression of NNE stress after the Indosinian Triassic period,the continent-continent collision turning into the continent-continent subduction of the North China plate and the Southern China plate.The strata are deformed with NWW due to extrusion,a series of folds and reverse faults and similar NWW trend of axial plane and cross section are formed,a single nappe developed inside the duplex and various lineation and foliation,which indicates a period of nappestructure track with NNE-SSW.?.According to stereographic projection analysis of the penetrating strata fracture occurrence in Huangbeiling-Shibaogou area 6 geological section showed that another tectonic process results on stress field of the late research area,a series of NNE trending small normal faults were developed,and early NWW trending structures were cut by them,the granite porphyry is developed at the intersection,the ore bearing hydrothermal fluids during late Yanshanian period were ascending and migrating along the intersection of NWW and NNE trending structures.The properties of intersection lineation,small ptygmatic folds and associated crenulation cleavage are all indicative of another NWW-SEE extensional tectonic environment.