Lead-Zinc Polymetallic Metallogenic Series And Prospecting Direction Of Huanggangliang-ganzhuermiao Metallogenic Belt, Inner Mongolia

The Southern Great Xing’an Range is famous nonferrous metal base andimportant Pb-Zn-W-Mo-Sn-Fe polymetallic mineral assemblage zone in north China,and Huanggangliang-ganzhuermiao metallogenic belt is one of the most importantpolymetallic metallogenic belts in the Southern Great Xing’an Range. The tectonicevolution history of study area can be divided into two stages:Paleo-Asiatic oceantectonic domain stage and circum-Pacific tectonic domain stage. Systematicallystudies of petrology, geochemistry, zircon U-Pb chronology have shown that theearly Mesozoic Triassic diagenetic mineralization events in Huanggangliang-ganzhuermiao metallogenic belt were evolved by continental collision or post-collisional after Paleo-Asian ocean closed, and the large-scale magmatism andmineralization during early Cretaceous was formed in the environment of back-arcextension which was caused by subduction of the ancient Pacific.According to the characteristics of mineralization,the main deposits in the studyarea can be divided into three categories: skarn type(Haobugao Pb-Zn deposit,Baiyinnuoer Pb-Zn deposit and Huanggangliang Sn-Fe deposit), porphyrytype(Dongshanwan W-Mo doposit) and hydrothermal vein type (Shuangjianzishansilver polymetallic deposits, Dajing Sn-Cu polymetallic deposit). The study of S,Pbisotopes and fluid inclusions implies that the ore-forming materials of skarn typedeposit were derived from deep source magma activity, the early ore-forming fluid is belonged to high temperature-high salinity immiscible H2O-NaCl hydrothermalsystem, and it gradually transformed to the low temperature-low salinity of H2O-NaCl system hydrothermal solutions. The ore-forming fluid migration process had aobviously participation of meteoric water and formation material. The earlyore-forming fluid of porphyry type deposits in the study area is derived fromcrystallization and differentiation of the cretaceous granite porphyry, accompanied bya mount of meteoric water in the late mineralization stage. Hydrothermal vein typedeposit ore-forming materials also have the characteristics of deep source and theore-forming fluid is belonged to medium temperature, medium-low temperature H2O-NaCl hydrothermal system, and it mainly came from the mixture of magmatic waterand meteoric water. Study of chronology shows that the formation of BaiyinnuoerPb-Zn deposit (skarn type) was early Triassic (about244Ma),and the formation ofHaobugao Pb-Zn deposit, Huanggang Sn-Fe deposit (skarn type), DongshanwanW-Mo deposit (porphyry type), Shuangjianshan silver deposit, Dajing Sn-Cu deposit(hydrothermal vein type) are related to the early Cretaceous magmatic activities(about132Ma and143Ma).The polymetallic deposits in Huanggangliang-ganzhuermiao metallogenic beltcan be divided into two metallogenic series:The first one is(Ag-Pb-Zn-Cu-Mo)-polymetallic metallogenic series which is related to the middle-late Triassic-intermediate-acid intrusion, and the other one is (Sn-Fe-W-Mo-Pb-Zn-Cu-Ag)polymetallic metallogenic series which is related to the early cretaceous magmaticactivities. The latter one can be furtherly divided into three sub-metallogenic series:①Pb-Zn-Cu-Ag sub-polymetallic metallogenic series related to the early cretaceousintermediate-acid magmatism(Haobugao, Shuangjianzishan).②W-Mo-Pb-Zn-Agsub-polymetallic metallogenic series related to the early cretaceous intermediate-acidintrusion③W-Sn-Fe-Cu sub-polymetallic series related to the early cretaceousintermediate-acid intrusion.The output and distribution of different types of polymetallic deposits inHuanggangliang-ganzhuermiao metallogenic belt is jointly controlled by strata,structure and magmatic rocks, permian strata, mesozoic acidic, fault and geophysical-geochemical anomaly are important prospecting marks of polymetallicdeposit in the area.Finally， this paper established Huang Ganggangliang-ganzhuermiao area multivariate geological information database, and chose thePermian strata, stratigraphic combination entropy anomaly, geochemical anomaliesand other information as evidence, and carried out metallogenic prediction researchof polymetallic deposits which was based on evidence weight model.