| The research area is located in the tongren complex fold deformation area of the qiannan depression.This through field geological survey and indoor synthetic analysis,using the method of structural analysis,system research shi bing-town far dynamics mechanism of tectonic belt,tectonic evolution,and combining the stratigraphic correlation,geochemistry,ore deposit geological characteristics,discusses the east-west tectonic belt of sedimentary rocks,magmatic rocks,mineral control,get the following:(1)shi bing-town far east-west tectonic belt of the kinematics mechanism and structural evolution process as follows:(1)the caledonian movement period(DouYun movement period)is in the area under the action of ns compressional stress,strain produced nearly east-west,formed a certain scale in the study area of east-west fault,fold,etc.,DouYun sports make the most of the study area uplift formed land,control of the study area of the late ordovician to the early sedimentary and volcanic rocks.(2)during indosinian to yanshanian movement is the east-west extrusion stress and north and south to counterclockwise,under the action of couple stress formed the north north east,near east-west strain,formed a study area north north east to folds,faults,and nearly east-west tension fracture,the phase structure and closely related to the formation of barite ore,lead-zinc deposit in the study area,occurred during indosinian to yanshanian movement in huaxia plot to intracontinental subduction of the Yangtze massif thrust orogeny.(3)areas during Himalayan movement by east-west counterclockwise of couple stress,the east-west shear strain,forming the east-west fault line left translation,in the study area Himalayan movement to the subduction of the Pacific plate to Eurasian plate by regional east-west counterclockwise couple effect,further produce shear deformation,superposition strike-slip deformation points,translation,etc.After the above multi-stage tectonic action,the near-east-west structural belt is formed.(2)the potash-magnesium lamprophyres(cear)in jiangkai village,shibing county were of right-leaning distribution pattern with light rare earth enrichment,with typical characteristics of potash-magnesium cear(cear).The fractional fraying of light and heavy rare earth is obvious,with rich mamma-derived magma genesis characteristics,indicating that the diagenetic material of kappa kappa is derived from deep crust granite,which strongly proves that the shibing-zhenyuan east-west fault is a deep basement fault.In the middle caledonian tectonic movement(duyun movement),the magma upwelling of the extensional deep fault was preserved in the anticlinal core with weak tectonic conditions.(3)lead,zinc and barite deposits in the study area are closely related to the eastwest structure in space.The shibing-zhenyuan fault was formed during the middle caledonian movement(duyun movement),but the middle caledonian movement formed compressional faults,which were unfavorable to the infiltration of tianshui and the migration of ore-forming materials.During the indo-indo-yanshan movement,due to the east-west compressive stress and the south-north anticlockwise couple stress,the near east-west tensile fault was formed,which provided favorable conditions for the infiltration of tianshui and the migration of ore-forming materials. |
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