Structural Features And The Control Significance Of Cu-Ni Sulphide Deposits Of The Hongqiling

Magmatic sulfide deposits is the main source of nickel production in the world today. As this kind of ore deposit besides produces the nickel, but also coexists with the copper, the cobalt, the platinum race, the gold and so on metals. So people pay attention to them because of the enormous economic value.Cu-Ni sulphide deposits of our country are in large quantity and in small scale.Most of them are hosted in the belt area or in Orogenic Belt of different times and spatial distribution of the transitional zone. (Tang Zhong li, 1996).Hongqiling and other deposits-Piaohaichuan,Changren and Zhangxiang of Jilin Province are with the similar geological back-ground,so they areConsidered to be the thing that has serial copper nickel sulphide mineral deposit of the same cause under the same structure environment (Chen Zi cheng,1984; Fu-yuan W u et al ,2004).Hongqiling area is located in the flanking of the Hufahe Fracture Zone.In this area ,there are more than 30 basic ultrabasic rocks. These rocks were emplaced in the NW structure of the sub-Huifahe fracture,and their diagenesis and mineralization were strictly controlled by stuctural structures, therefore, the research of the environment and the construction of the diagenesis and mineralization has to be of significance.At present,the research of geological characteristics, metallogenic model, mineral geochemical characteristics and genesis of the deposits of nickel sulphide deposit in Hongqiling is more detailed, but the research about diagenesis and mineralization structure of the main rocks is relatively less.During master,I was privileged to participate in the project,which is responsible by Hao libo pro and Lu Jilong pro,that taking over resource prospecting of national crisis mine- The metallogenic regularity conclusion of Jilin Hongqiling nickel deposit.I carried out a large amount of field observations and laboratory consolidation studies about metall -ogenic geological background,regional structural feature diagenesis and mineralization structure of the typical rocks of Hongqiling Cu-Ni sulphide mineral deposit,so I have accumulated the abundant basic materials.This paper studies the formation age and mechanism of Hongqiling mining area based on the field observations of structural characteristics, petrography with mic -roscope and microstructure studies,and combined with previous structure,and furtherly studies their control significance to Cu-Ni sulfide deposit.Main faults in this area is the EW, NW, NE, SN direction. According to gravity anomaly and the distribution of to the anomalous relationship of the mining area ,it can be determined that faults from early to late is EW,NW,NE→SN. Huifa River deep fault is the NE direction, with the characteristics of many repeated activities. In addition, there are some late faults with the formation of parallel NE trending,and they have a destructive effect on the rock and the ore body. The main control structure of rocks and deposit is the NW trending faults.Field observations show that the direction of the fault are mostly pressure-shear, and they also show a tensional features in a certain period.Such as F1 which controlsⅠr ock belt overally shows Compression and Torsion,but it shows both Compression and Torsion and tensional characteristics . In the vicinity of NO.7rock mass.It can be seen from 1:10 000 gravity anomaly level 90°of derivative map of the Hong qiling that SN trending faults are generally shorter, and is the tensional fault, so the principal compressive stress is north-south.X joints are well developed In the region, and their strike mainly is 40°-50°, 310°-320°.The area mainly was squeezed by north-south compression when X joints formated.Field observations show that the joints is not affected by later tectonic transformation,and they have no penetration of dike. So,we judge that SN faults and X joints formed in the same period.Ore-bearing rocks mainly distribute inⅠrock belt and they are contonrolled by F1 fault. F1 fault has multiple repeated activities.The early activity was the sinistral piezotropy; When Ore-bearing magma invades the position,it was dextral tensional; However ,it transfered the sinistral movement in the later period.From the plane distribution ofⅠrock belt ,from northwest (NO.2→NO.1→NO.3→NO.9→NO.7 rock mass) to the southeast ,the rock mass have the echelon distri-bution roughly, and they are belt-shaped,the arteries shape,and they distributes approximately in the identical fault zone.they have the characteristic of pinch-out reappearance. The compression and torsion fault which contonroled this rock belt showed waving characteristic in the forming initial period, and the two walls of fault had the horizontal direction dislocation in the later period .It formed a series of arteries shape, belt-shaped, the bean pod shape space, and it provided the place for the upper mantle mafic-ultramafic magma .According to mirror under microstructures, EBSD quartz fabric chart and heavy magnetism unusual distribution map, and unifies predecessor's material and the geostructure background, I think that the structure evolution activity divided into four issues at least in this area. late caledonian, it formed north west control structure of rocks and deposit under areal structure stress field function;.at the same time ,Huifa River had intensifies moving and the cutting depth further enlarged, so the curtain magma frommantle taking the opportunity invaded and emplaced in the faults of NWⅡrock belt. Late hercynian- early indo-chinese, it had the medium degree deterioration distortion function and formed the Hulan group deterioration rock series in this area under the northern east 50°near horizontal direction's extrusion.Late Indo-Chinese, Huifa River had a large-scale left strike-slip movement and had traction function to enable it to have tensional wrench characteristic to a certain extent. It provided the space for rochs ofⅠrock belt. Early cretaceous-tertiary, the whole area was in an extensional environment and Huifa River had intensifies moving once again .NW faults had a sinistral movement, and the magma from mantle invaded once more at the same time formedⅢbelt rock masses.In summary, each belt rock mass's formation had the extremely close relationship with the Huifa River deep fault and the activity in Hongqiling.