Ore Genesis And Metallogenic Series Of Cuihongshan Area In Xunke，Heilongjiang Province

The study of metallogenic series is an important thought for research of regionalmetallogenic regularity, it is to explore genesis of different types of mineral deposit that isformed by the same geological period and the same geological age. The study ofmetallogenic series has the most direct relationship with guiding prospecting andexploitation of mineral resources. The mine of Cuihongshan is located in easternYichun-Yanshou metallogenic belt, it is an important part of the metallogenic belt that ison active collaged zone between land mass of Xiaoxing’anling–Songnen andJiamusi–Xingkai. By the double impact of the regional tectonic system of ancient AsianOcean and the Pacific Rim and intrusion of magma in Caledonia to Yanshanian, there is alarge number of endogenous mineral deposit associated with magmatism in the region.Based on the geological conditions, characteristics of mineralization and types of orein Cuihongshan mine, explore the genetic relationship between them. Besides, study threetypical mineral deposits in this area anatomically. Petrography show that the rockassociated to skarn deposits of Cuihongshan is coarse-grainedadamellite and partialchange into biotite monzonite granite, mineralization associated with granodiorite series isnot close. The rock of mineralization in molybdenum porphyry deposit of Hodge Creek ismainly related to granodiorite, and the rock of Kubin hydrothermal deposits is mainlyrelated to adamellite. Geochemical characteristics of the samples show content of SiO2>66%, content of Na2O+K2O is between7.84%and9.39%, content of K2O/Na2O isbetween1.10and1.72, content of Al2O3is between12.45%and14.90%, samples belongto metaluminous high-K calc-alkaline series.Characteristic of trace element displays thatRb, Sr and other large LILE are enriched, Nb, Ta and other high field strength elementsare depleted. Characteristics of REE shows that light rare earth is relatively enriched andHREE is relatively depleted. The rock has feature of granite in type-I and type-A.The result of LA-ICP-MS zircon U-Pb isotopic shows that206Pb/238U age’s weightedaverage of granodiorite, monzonite granite and biotite monzonite granite are484±4.7Ma,198.9±1.6Ma and199.0±3.2Ma. Combining mineralization ages of granodiorite andmonzonite granite in Hodge Creek (184Ma~186Ma), suggest that mineralization ofdeposits in Cuihongshan occurs mainly in the early Yanshanian.The strontium isotope of rock of mine in Cuihongshan shows that87Sr/86Sr is0.767605. It may indicate the formation of magma is related to molten material of shell.87Sr/86Sr of granite of Yanshanian are0.717454and0.723593, average is0.720523. It hasisotopic characteristics of contaminated magma. δ34S by sulfur isotope testing of pyrite,galena and other metal mineral in deposits of Cuihongshan is between1.2‰~5.78‰,close to the mantle (-3‰<δ34S<3‰), it suggests that crustal magma riched in mineralformed in partial melting of the lower crust induced by underplating of mantle-derivedbasaltic magma. And the crustal magma occurs contamination of crust and mantle with themantle-derived basaltic magma, sulfur and other elements in the mantle and otherore-forming elements get into system of shell source magma, which is involved inmineralization.Temperature of fluid inclusions of deposits of Cuihongshan and Hodge Creek showsthat homogenization temperatures of Cuihongshan is between174.7℃~372.3℃, the mainhomogenization temperatures is between240℃~280℃, Salinity is between (5.85~11.6)%NaCl eqv. And homogenization temperatures of Hodge Creek is between141℃~353℃,the main homogenization temperatures is between200℃~280℃, the salinity is between(1.22~9.73)%NaCl eqv. Fluids of ore-forming has the feature of H2O-NaCl that ismoderate temperature and low-moderate salinity. Fluids of ore-forming is mainly from magmatic water, and there is meteoric water mixing into fluids of ore-forming by processof mineralization.Through the study of the anatomy of typical deposits in the region set, it could besaid that output of deposits has some special properties. Fe, Mo, Pb, Zn deposits of skarn–hydrothermal are mainly distributed in contact belt between intermediate-felsic intrusionand carbonate rocks in Yanshanian. Cu, Mo deposits of porphyry type are are mainly inalteration belt where rocks occurred silicification and potash feldspathization by latehydrothermal fluid. Tectonic activity of Cuihongshan mine is frequently. The two groupsof fracture of NNE or near to SN direction and NW direction control the distribution ofvolcanic rocks in the zone, and the fracture provides channel for invasion and migration ofhydrothermal fluid after magmatism, and thus control storage and shape of the metalmineral deposits. As a result, the intersection of two faults is favorable position ofmineralization in Cuihongshan deposits set. The author divide a metallogenic series of CuiHong Shan deposits set into two metallogenic sub series, and establish the genesis modeldiagram initially, which provide a strong basis for regional prospecting, but also point outthe direction for the exploration of new deposits and prospecting deeply in existeddeposits.