Geological Characteristics and Discussion on Metallogenic Epoch of Zhengguang Gold Deposit, Heihe City, Heilongjiang Province

Heilongjiang Province,is located in the Duobaoshan metallogenic belt in the northeastern Great Hinggan Range. The Au-bearing veins occur in the contact zone between diorite pluton and the Middle Ordovician Duobaoshan Formation,and are controlled by faults. At present,the total gold reserve,that has been proved,is 12 tons. The deposit is discovered nearly one decade. So far, the ore-controlling structure, metallogenic regularity, oreforming material source and character -ristics of oreforming fluids, etc. have been done by some researchers these years. However, the rockforming and Ore-forming Age of the deposit is short of related research. Middle Ordovician Tongshan(O2t) and Duobao -shan formation(O2d,O2d,O2d) are the main strata in the Zhengguang gold deposit mining area, and Duobaoshan formation is the important source bed of this gold deposit.The fracture in the mining area is developed and has a long-term inheritance activities characteristics. The intrusive rocks outcropped in the mine are mainly diorite and a small amount of andesite and diorite porphyrite. Zhengguang gold deposit contains three ore body(I,II, III)and the II among them is the main ore body in the mining area, which is natived to diorite and Duobaoshan formation contact zone. The main ore body in the contact zone with the parallel to the small group of ore bodies which are strictly controlled by the contact zone and related fissure system. Ore types are mainly of crack belt zone-hosted alteration rock, followed by gold-bearing quartz fine network vein type. Wall rock alteration related to the mineralization are mainly silicification, sericitization and pyritization, and these alteration minerals often output together in space, which composed the beresitization and sericitization and to be the most important gold alteration type. This deposit mineralization can be divided into hydrothermal mineralization stage and supergene stage two metallogenic period .Then hydrothermal mineralization can be divided into four stages,i.e., quartzpyrite stage(1), quartz-polymetallic sulfide stage(2), calcite-quartzpolymetallic sulfide stage (3) and carbonate stage (4), with stages 2 and 3 as the main Au mineralization stages and characterized by complicated metallic mineral assemblage of pyrite-sphalerite-galenachalcopyrite ± native gold. We use the high precision LA-ICP-MS zircon U-Pb SHEN Jun, HE Mouchun and DING Zhenju, 2014. Geological Characteristics and Discussion on Metallogenic Epoch of Zhengguang Gold Deposit,Heihe City,Heilongjiang Province. Acta Geologica Sinica (English Edition), 88(supp. 2): 599-600.