Geological Characteristics And Prospecting Direction Of Xiaolonghe Tin Deposit In Tengchong, Western Yunnan

Xiao Longhe tin deposit is located in Tengchong block,which lies in the West Yunnan tin metallogenetic belt as well as in Tengchong-Lianghe tin metallogenetic belt subzone.We achieved the following results through analyzing the geological survey of mine,the occurrence feature of deposit,ore characteristics,mineralizing periods and the mineral arisen sequence:finding out the laws of ore body distribution,the traits of faults containing and controlling ore-body,the genesis of the deposit and general ore-forming age,summarizing ore controlling factors and the metallogenic regularities of this deposit.And on this basis,we combine geological conditions of the mining area,achievements in the geophysical and geochemical anomalies,the placer mineral anomalies,drawing a conclusion at prospecting direction.The main results achieved and understanding are as follows:1.The metasandstone of the Kong-shuhe Formation in the Upper Carboniferous with the inside and outside contract belt of granite associated with greisen,skarn,and altered granite are the main ore-bearing rocks.A flat dipping stratiform of skarn type,which is located in the inside and outside contract belt of granite;Areal distribution of greisen type in the lower of skarn;Steep veined of graisen-vein type,which is located in the crack of the granite.2.The SN-trending and NNW-trending fault as primary for the fault of mining area.Greisen vein with tin along NNW-trending fissures filling metasomatic mineralization,forming a mineralizing belt of greisen with tin,which extending to NNW-trending.3.The type of Xiao Longhe tin deposit is contact metasomatic skarn superposing gas into high-temperature hydrothermal greisen-type tin deposit.The medium-porphyry biotite granite of intrusions in mineralizasion(Mao Tianshi unite)belong to late Yanshanian Period deep-remelting continental crust of granite,which is mother roch of tin deposit..4.According to the characteristic of place mineral anomalies,combining geologic features of the mine with the type of the deposit,we can delimitate six promising prospecting in Xiao Longhe mine and its periphery.