Characteristics And Genesis Of Sb-Au Mineralization In Zhuanghuhe Area,Heihe County,Heilongjiang Province

Zhuanghuhe research area is located in the Duobaoshan ore collection area,which is within the Zalantun-Duobaoshan island arc belt in the coupling part of The Greater Hinging-Anling fold belt of the Tianshan-Xingmeng orogenic belt and the Ugeosynclinal uplift belt of the Lesser Hinging-Anling.Several antimony ore bodies have been discovered through the surface exploration trough exposure and a few drilling controls,but the size is small.Surface see article 1 gold orebody?Au??-1,article 5 of the antimony ore body?i.e.?,?-1,2,?,??-1?.The orebody and orebody are mainly controlled by the n W direction structure and occur in the structural belt,which is banded and lenticular.The hydrothermal metallogenic stage can be divided into three stages:I quartz-pyrite stage;II Quartz-pyrite-stibnite stage;III Quartz-calcite stage.Studies on fluid inclusions showed that there were a large number of inclusions in the veins containing ore.The two types of inclusions developed in the quartz pyrite stage were VL type and LV type inclusions respectively.The tested freezing point temperature ranges were-1.9??-6.2?and-1.8??-5.8?,respectively.The salinity values ranged from3.21%to 9.47 wt.%Na Cl eqv.and 3.05%to 8.94 wt.%Na Cl eqv.,respectively.The variation range of uniform temperature was 268.5??345.4?and 276.4??365.2?,respectively.VL inclusions were developed in the stage of quartz-pyrite and stibnite,and the freezing point temperature ranged from-1.8?to-4.5?.The salinity ranged from3.05%to 7.15 wt.%Na Cl eqv..The variation range of uniform temperature is203.5??281.6?.VL inclusions were developed in quartz-calcite stage,and the freezing point temperature ranged from-0.3?to-2.3?.The salinity ranged from 0.53%to 3.85wt.%Na Cl eqv.,respectively.The variation range of uniform temperature was 159.5??210.7?.Microthermometry results showed that the ore-forming fluid was H₂O-Na Cl system with low temperature and low salinity.The hydrogen and oxygen isotope results showed that the fluid in stage II was mainly from the mixed hydrothermal fluid of magma and meteoric water,while the fluid in stage III gradually evolved into one dominated by meteoric water.The value of?¹⁸O_H2Ofor stage II minerals was 4.6‰,3.8‰and 2.2‰,respectively.The value of delta?D_V-SMOWof quartz mineral in stage III is-92.56‰,-90.10‰and-89.67‰,and the value of Delta?¹⁸O_V-SMOWis 3.4‰,2.2‰and 5.2‰,respectively.The values of delta?D_V-SMOWfor calcitonite in stage III are-82.57‰,-96.30‰and-110.60‰,and the values of Delta?¹⁸O_V-SMOWare-0.7‰,1.0‰and 0.6‰,respectively.The value of?¹⁸O_H2Oof stage III quartz mineral is-9.1‰,-11.3‰and-7.6‰,respectively.The value of?¹⁸O_H2Ofor the stage III calcite mineral is-14.3‰,-12.9‰and-13.7‰,respectively.It shows that the fluid in stage II is mainly from the mixed hydrothermal solution of magma and meteoric water,and the fluid in stage III gradually evolved into the fluid dominated by meteoric water.The age of the outcropping granite was 302.4±4.4Ma,the age of quartz diorite was298.3±1.9 Ma and 171.2±1.7 Ma.Granodiorite,the late carboniferous to the performance of main elements rich alkali,high potassium,belongs to the quasi aluminum-weakly peraluminous high potassium calc-alkaline series rocks,enrichment of trace elements spider diagram show the light rare earth elements and large ion lithophile elements,loss of heavy rare earth elements and high field strength elements,its genetic discrimination diagram of rock sample fall within the scope of the I type granite.It is speculated that the tectonic environment is the subduction environment from the Ancient Asian Ocean to the North China Craton.It is suggested that it may have formed at the edge of active continents.Jurassic quartz diorite geochemical study shows that the main elements of the expression is rich alkali,high potassium,belongs to the aluminum potassium calc-alkaline series rocks,spider diagram of trace elements Pb,Nd relative enrichment,and Nb,Ta,Ti relative losses,characterized by enrichment of light rare earth elements,the curve is steep,heavy rare earth relatively flat,change is not obvious.In the tectonic discrimination diagram,the samples in the rocks are close to the pre-plate collision region,and have the island arc magmatic geochemical characteristics,which are inferred to be island arc granitic rocks formed at the active continental margin under the action of paleo-Pacific subduction.Based on the above studies on the geological characteristics,ore-forming fluid properties and rock mass age of antimony gold mineralization in zhuanghuhe area,this paper considers that the antimony gold mineralization in zhuanghuhe experienced the tectonic evolution from the paleo Asian Ocean to the paleo Pacific Ocean,and the mineralization was formed in the active continental margin tectonic environment formed during the subduction of the ancient Pacific Ocean in the Middle Jurassic,which belongs to the epithermal deposit.