Study On The Geological Characteristics And Metallogenic Prognosis Of Xiaokele And 972 Highland Gold Polymetallic Deposit In Daxinganling,Heilongjiang Province

Xiaokele and 972 highland gold polymetallic deposit is located in Xinlin Area,east of Xinlin Town of Daxinganling in Heilongjiang province,which is a typical porphyry gold polymetallic deposit in Daxinganling,Heilongjiang Province.The geotectonic location is in the eastern slope of the northern part of the Mesozoic volcanic zone in Daxinganling,Ermuer Mountain Intermediate uplift of Ererguna Massif.It belongs to Daxinganling polymetallic metallogenic belt.There are complex strata in the mining area.Guanghua group and Ganhe group of Lower Cretacic,Yaluhe group of Upper Pleistocene series and Holocene series of Quaternary are exposed in large area.The distribution of magmatic rocks in the mining area is scattered,and there are mainly intrusion rocks,with a little dikes sporadically distributed.The Early Cretaceous granodiorite porphyry is an important ore-bearing rock mass in Xiaokele and 972 highland gold polymetallic deposits.In the study area,the diagenetic age of granodiorite porphyry is 142 Ma,which belongs to the Early Cretaceous,Late Yanshanian magma event.Rock geochemical data show that diorite porphyrite is of high-K calc-alkaline series,quasi-aluminum rocks.The magmatic mineralization is closely related to the circum-pacific tectonic system.The diorite porphyrite is formed in extrusion-stretching transition environment.Xiaokele and 972 highland gold polymetallic diggings are divided in to three researchareas,area I?area II and area III.At present the project exposes that the ore body are mainly distributed in area I,and the ore body is mainly blind ore body,seen in bore hole.The wall rock is mostly granodiorite porphyry.The study found that metal minerals are mainly chalcopyrite,molybdenite.The ore structures are mainly disseminated structure and vein structure.The wall rock alteration of ore body is characterized by typical surface alteration.From inside to outside,there are potassic alteration zone(potassium)— like phyllite alteration zone(silicification,sericitization)— argillaceous alteration zone(kaolinitization)— propylitization zone(carbonation,chloritization and epidotization)(Chenjun,2015).The ore is better exposed in the north of area I.In this study,drilling engineering is used to control the extension of the blind ore body in the deep,with new discovery of copper,molybdenum and copper molybdenum ore body,and they are mainly typical beresite,obviously controlled by the rock mass and structure.The ore minerals can be seen as disseminated,fine vein and lump pyrite,and disseminated,fine vein disseminated chalcopyrite and molybdenite.Galena and sphalerite are locally visible under the microscope.Study of fluid inclusions shows that i In the main mineralization stage of the mining area,the quartz polymetallic sulfide stage,is mainly composed of two-phase fluid inclusions of gas-liquid type and multiphase fluid inclusions of daughter mineral-bearing type.The characteristics of ore-forming fluid show middle temperature and high salinity.The metallogenic pressure of the deposit is 20 ~ 50 MPa,and the metallogenic depth is 0.7~ 1.7km.Compared Xiaokele and 972 highland gold polymetallic deposit with other typical porphyry deposits at home and abroad,we consider that genetic type of Xiaokele and 972 highland gold polymetallic deposit should be porphyry deposit.Based on the analysis of geological conditions and the results of geophysical and geochemical prospecting anomalies,it is believed that the genesis of this deposit is related to the granodiorite porphyry discovered in this area,and the northern part of area I is divided into key metallogenic area and key target for the next step.