Metallogenesis And Ore Prospecting Indicators Of The Jinchang Gold Deposit,Heilongjiang Province

Jinchang gold deposit is in the joint position of the uplifted zone of Proterozoic Taipingling dones and Mesozoic Laoheishan fault basin,which is belong in the southern margin of Xingkai massif.This area is located in the south margin of North China plate,in the north part of Jiamusi,Xingkai plate,and also in the contact site of the central Asia-Mongolia tectonic domain and the West Pacific.Through collecting the basic geologic information,studying outside in the wild and analyzing test data of Jinchang gold deposit,the author summarized the geological background and the characteristics of the ore body;and also studied the characteristics of the fluid inclusions and the isotope features to analizethe the ore genesis.And putting the overall information togerther,which was with the geophysical prospecting,chemical prospecting and remote sensing data to summarize the prospecting indicators.By doning the research,the main understanding can be achieved:This paper classified the ore body into two kinds,the breccia type and the fracture filling vein type.The first type ore body was wide spread in the northwest-trending as a string of beads,including invading breccia type and caving-in breccia type.The second type ore body was grouped in the Banjiegou area,which was influenced by deep magma,the ring crack and the radial fracture.Considering of the breccia type ore body,the fluid inclutions were composed of pure-gas,gas-liquid and including mineral ones.By the proving of the fluid inclutions factors and physical features,the auther found that the fluid of Jinchang gold deposit were two migration directions,one was from J-0 to J-1,and the other was heading from J-XI to J-1.The fracture filling vein type's fluid inclution types were gas-liquid and including mineral ones,and the temperature of the ? ore body was little higher than ? ore body and No.18 ore body.So the order of ore fluids in the ore body of this type was from the ring altered rock type to the radial fracture filling vein type.By analizing the H-O isotpe data,the auther made sure the fluid of the breccia type ore body was meteoritic water,and the other type was main from meteoritic water and reformed water.Comparing the value of?34SV-CDT(‰),these two types had little difference;the former type's value was between 2‰~4‰;for the later type,the value of the No.18 ore body was lower than the ? ore body.They two both had the characteristic of the deep sulphur.By the proving of the value of 206Pb/204 Pb was J-1>J-0>?ore body,the value of 207Pb/204 Pb was J-I>?> J-0 ore body,and the value of 208Pb/204 Pb,the auther indicated that the Pb came from the mantle and orogenic belt,and mixed the material from the crust.The prospecting indicators of the breccia type ore body were weak wedge of the linear structure and the group of silicification,pyritization and brass mineralizatinon.And the prospecting indicators of the fracture filling vein type ore body were ring and radial structure frature and silicification,pyritization,sericitization and kaolinization.Besides,the weak part of different lithology and the fluid inclutions including minerals with high temperature and salinity features in this ore district,were all the prospecting indicators of rich-Au-Cu area.