Genetic Mineralogy And Deep Prospects Of Wulong Gold Deposit In Liaoning Province

WuLong gold deposit in Liaoning province is located in the eastern North China Platform,southern Yingkou-Kuandian palaeohigh,northwestern Yalu River metallogenic belt.Based on the previous researches,the theories and methods of genesis minerageny and prospecting mineralogy are used to study the typmorphic characteristics of pyrite during their main mineralization stages,and to discuss the mineral deposit genesis and ore-forming hydrothermal source,which is indicative of science to the deep ore prospecting.The gold veins was confined to 2th Well of WuLong gold field.The S/Fe values of Pyrite ranges from 1.90 to 1.98 in 2th Well of WuLong gold field,which indicates that Pyrite is sulfur deficiency type.And the ?(Fe)/ ?(S+As)values of Pyrite ranges from 0.888 to 0.908,which indicates that the ore-forming depth of Pyrite is medium to shallow.Pyrite is enriched weakly in LREE,have deficit HREE,varying degrees of negative anomaly of Ce,relatively obvious trends of positive or negative anomaly of Eu.The Co/Ni values ranges from 0.21 to 4.20,which will increase with the increase of depth.The front halo indicator element is As.The near halo indicator elements are Pb,Ag,Zn.Ni,Co are the rear halo indicator elements.These halo has superimposed structure,which indicates that the formation of ore deposit resulted from multi-stages and multi-phase mineralization.Trace elements combination of(As+Sb+Se+Te),(Ag+Cu+Pb+Zn),(Co+Ni+Ti+Cr)of Pyrite in ore bodies with different elevation shows cycle oscillating variation characteristics as a whole in vertical direction,and it proves that the gold deposit resuls from the multistages superposition of ore-bearing hydrothermal.The thermoelectric test results of Pyrite in main mineralization stages shows that the most thermal electricity type is P-type,and thermoelectric coefficient ranges from ?319.5to?333.9?V/?,and its histogram is double peak type.In space,the occurrence rate of P-typefluctuates as a “S” shape with depth from-454 m to-609 m,and the occurrence rate is greater than 80 percent when the depth is deeper than-609 m,which shows an obvious increased trend with the depth increasing.Above statement shows that ore-bodies with depth from-454 m to-609 m are located in middle-upper part of ore deposit.Based on the thermoelectric coefficient calculation of Pyrite,the denudationrate(?)of ore-bearing veins in 2th Well with depth-454~-609 m ranges from 29.5to 64.5%,which presents fluctuation change characteristics.When the depth is deeper than-609 m,?shows an obvious decreased trend,which indicates thatore bodies located in middle-upper part of ore deposit and deep prospecting potential is still greater.According to the results of thermoelectric coefficient calculation,the formation temperature of Pyrite of 2th,3th ore-bearing vein during main mineralization stages in 2th Well ranges from 75.4 to 384.8?,which can be further divided into two temperature section.The high one is 300~360 which peak value is 330? ?,and the medium and low temperature is 100~280?which peak value is 200?,which indicates that the deposit was formed after two mineralization stages.The abnormal content of the trace elements Ag,Cu,As,Pb,Bi,Mo of ore has certain regularity and differences.Moreover,the element isogramtrend graph in vertical projection presents that high value areainclined to south as bead-like shape,which indicates that ore-formingfluid passageinclined to south.Among them,Bi?As?Cu?Pb?Ag isograms anomaly area overlay with each other,and two high value south areas with depth-609 m is not closed downward,which indicates that the ore bodies have downward extension trend.Therefore,the paper deduces that deep prospecting potential in south area is still greater.