Geological And Geochemical Characteristics From Duobaoshan Mining Granitic Rock In Heilongjiang Province

Duobaoshan copper deposit is located in the Nenjiang County of Heihe City in Heilongjiang Province.Its structural location belongs to the Early Paleozoic epicontinental accretional belt and Duobaoshan Ordovician island arc type active belt in the northern of Daxinganling of the eastern of Central Asian Orogenic Belt.The deposit is located in the easternmost Xingmeng orogenic belt which is at the intersection position of Daxinganling fold belt and Jilin Heilongjiang fold belt.For the outcrop in the area,is mainly volcanic-clastic rocks and sand mudstone of Ordovician and Silurian.Middle Ordovician Duobaoshan formation rocks cover at the top of the orebody.Caledonian granodiorites have the closest relations with mineralization.Middle and bottom of the ore bodies are in the granodiorite.There are mainly three groups of ore-controlling structure in the mining:NW construction,NW and NE arc tectonic belt and NNE structure.In Duobaoshan deposit,ore body is surrounded porphyry.The occurrence of ore body and porphyry is the same.Duobaoshan deposit Main Zone(3 bands)are mainly distributed in the granodiorite,but the top is in andesite.Rock at the surface is cyrtospirifer shape.The boundary what is contacting rock is extremely irregular,and partially penetrating the rock with small rocks.The rock of the contacting zong and the xenoliths in rock occur in varying degrees of thermal metamorphism.Main rock is composed of granodiorite.It was gray and light gray.It generally has a hypidiomorphic granular structure.Rock alteration is very strong.It is widely developed sericitization.Quartz monzodiorite is in the northeast of the mine.The surface contacting with rock is neat.There are significant thermal metamorphism and assimilation phenomenon.By CIPW and QAP,the rocks are mainly granodiorite and quartz monzodiorite.Geochemical data analysis shows that rocks are a high sodium calc-alkaline rock and aluminum rock.Rock is characterized by:low silica,high sodium,high Al,calc-alkaline,low potassium,high magnesium and high calcium.And they show that loss Ce Nb,Ta,P,Zr,Hf and Ti high field-strength elements,and the relative enrichment with Rb,Ba,K,Sr and Pb geochemistry lively LILE element.In addition,they both show LREE-rich.Dephlegmation of LREE and HREE is not obvious.Eu a'bnormal is not obvious.?Eu average value is 1.06.Positive Eu a'bnormal is very weak.Through the analysis of major,trace and rare earth elements,indicating that granitic rock is mainly formed in the plate collision before and after the plate collision uplift transitional tectonic environment.In other words,It formed relatedly to plate subduction It also shows that it has geochemical correlated,which losing high field strength element Nb and LILE-rich.With previous isotope data and tectonic background,tectonic environment of granitic rock is likely to be plate subduction volcanic arc tectonic environment.