Study On Genesis Of Kaolin Deposits In Nenjiang Area,Heilongjiang Province

The study area is located in the Nenjiang area of Heilongjiang Province.The tectonic location is Xing’anling-Inner Mongolia geosynclinal fold area,Songnen massif,the Western fault terrace area of Songnen fault（depression）belt and the northern dipping area.The metallogenic geological conditions are superior and the non-metallic mineral resources are rich.The research area is located in the South 30km of Nenjiang County,and is located in the Daxijiang Heshan kaolin metallogenic belt.Therefore,the study of the metallogenic geological characteristics of the kaolin deposits in this area is helpful to further explore the prospecting direction and metallogenic prediction in the future.The outcropping strata in the area are mainly the Upper Proterozoic One-sided Slope Group（Pt₃ym）,Ordovician Dobaoshan Formation（O₂d）,Lower Cretaceous Longjiang Formation（K₁l）,Guanghua Formation（K₁gn）,Ganhe Formation（K₁g）,Upper Cretaceous Nenjiang Formation（K₂n）,Neogene-Upper Pliocene Sunwu Formation(N_1-2s)and Old Heishan Formation.Xuan Wuyan（beta Q₄¹）,Holocene high floodplain accumulation（Q₄¹）and low floodplain accumulation（Q₄²）.The late Yanshan intrusive rocks are exposed in the area.Kaolin ore bodies occur in the strata of Sunwu Formation of Neogene in layered or layered form.The ore bodies are composed of kaolin,feldspar and quartz.The occurrence of the ore bodies is consistent with the strata.Kaolin deposits are controlled by strata.The ore structure is mainly layered structure,medium-fine grained sandy structure,loosely weak cemented low diagenesis,the main cement between particles is kaolin,porous cementation,clastic particles are scaffold-like contact of the original complex structure.From the study of ore mineral assemblage,ore fabric and mineral characteristics,it is considered that the deposit has the characteristics of fluvial-lacustrine sedimentary weathering and mineralization.Based on the above research,the metallogenic geological conditions in this area are preliminarily analyzed.Combined with the comprehensive information of geology,geophysics,geochemistry,remote sensing and mineral resources in the study area,the metallogenic prognosis is carried out in the south of Nenjiang River,and the prognostic area is 600 km².