Research And Application On Geological-geophysical Prospecting Model Of Xiarihamu Copper-nickel Deposit,Qinhai Province

The Xiarihamu deposit is located in the eastern part of the eastern Kunlun Mountains of the Qinghai-Tibet Plateau and in the southern margin of the Qaidam Basin.The administrative divisions are under the jurisdiction of Golmud City,Haixi Mongolian-Tibetan Autonomous Prefecture,Qinghai Province.The area is sparsely populated,because the discovery of Hamu super-large copper-nickel sulfide deposit in summer in recent years has attracted worldwide attention.The mining area is located in the eastern Kunlun orogenic belt.The Eastern Kunlun orogenic belt starts from the Altun fault in the west,ends at the Wahongshan hot spring fault in the east,adjacent to the Qaidam Basin in the north,and adjacent to the Koxilibayan Hara orogenic belt in the south.In general,the tectonic lines in the area are nearly EW-trending,and there are three EW-trending regional deep faults in the north,middle and south of Kunming,which are the demarcation lines of different tectonic units in East Kunming and the Bayan Hara orogenic belt in the south.The Xiarihamu r ha Mu mining area lies between kunbei and Kunzhong faults.The strata exposed in the mining area are mainly Jinshuikou Group,including striped,striped biotite plagioclase gneiss,biotite schist,quartz schist and marble.The faults in the mining area are well developed and characterized by multi-period and multi-group activities.Generally,they can be divided into four groups according to their distribution direction: nearly east-west,northwest-west,northeast and northeast faults.The ore-controlling structure of the mining area is a nearly east-west fault in the middle part of the mining area,which belongs to the secondary fault of the Kaimuqi River-Suhaitou River deep fault and is the ascending passage of ultramafic-mafic magma.Copper-nickel ore bodies are mainly hosted by mafic-ultramafic complex.The ore-hosting lithofacies are mainly peridotite,pyroxene and gabbro facies.The rich lithofacies are peridotite and pyroxene facies.The ore is mainly sulfide ore,the ore metal minerals are pyrrhotite,the copper minerals are chalcopyrite and the nickel minerals ar e nickel chalcopyrite.The ore structure of iron ore is mainly granular structure,metasomatic structure and sponge meteorite structure.The ore structure is mainly disseminated structure,star-dot structure and mottled structure.The main metal sulfide pyrrhotite in the ore is followed by magnetite,nickel pyrite,chalcopyrite and other minerals.The ore body can cause magnetic anomalies ranging from 1500 n T to 2000 n T.The abnormal resistivity of ore bodies is mainly characterized by low resistivity and high polarization.Mineralization alteration markers: carbonation,limonization,occasional chalcopyrite mineralization,nickel pyritization and other mineralization alterations into direct prospecting markers.The main prospecting markers are: ultrabasic rock mass;pyrrhotite,nickel pyrite,chalcopyrite,magnetite;carbonation,limonization,occasional chalcopyrite mineralization,nickel pyritization and other mineralization alterations.It has become a direct prospecting indicator;low resistivity,high polarization anomaly and high magnetic characteristics.The research idea:this paper summarizes the effective methods of geological prospecting and geophysical prospecting in Xiarihamu mining area in summer,and extracts the geological characteristics,geophysical characteristics and prospecting marks of the deposit.In view of the multi-solution of the inverse problem of geophysical prospecting,geophysical prospecting methods are used to establish constraints between geological interpretation and geophysical methods,and then to establish deposits.Comprehensive geological geophysical model.Establishing a typical prospecting model for ore deposits is a necessary step for regional metallogenic prognosis.By combining geological-geophysical prospecting model with geochemical data,regional prediction elements are extracted,prospecting areas are selected and prospecting target areas are predicted in order to achieve the effect of expanding prospecting scale.