| Haigou gold deposit is located in Liangjiang town,Antu country,Yanbian Korean Autonomous Prefecture of Jilin Province,located in the southeastern Jipigou-Haigou gold belt,the northern North China plate,the northeast side adjacent to the Xing-Meng Orogenic Belt.The study area of the Archean period belongs to the intense activity of the granite-greenstone belt,and then through the Paleozoic paleo-Asian oceanic tectonic domain and Mesozoic Pacific tectonic domain tectonic magmatic activity superposition and transformation.The Haigou gold deposit between the NW Qingchaguan-Baishuitan fault zone and NE Ji'an-Songjianghe fault zone.Main geological units in the Haigou deposit include the Mesoproterozoic Selouhe metamorphic rock,Hercynian period Haigou monzonite-monzonitic granite,Yanshan period Shirengou biotite adamellite,Dahaigou gabbro-diorite and various types of vein rocks,such as diorite porphyry,syenodiorite porphyry,diabase.The Haigou gold deposit is mainly produced in the Haigou rock mass,more than 50 gold veins have been found.The gold veins(ore body)are mainly controlled by the fault structure,the NE-NNE fault structure is the most important ore-controlling and ore-bearing structure,NE-NNE trending 28#,38#,43# veins and NW-trending 33# vein are the main production of the Haigou gold deposit.The mineralization type is dominated by gold-bearing quartz veins,the alteration rock type gold mineralization is less,mainly distributed in the deep and edge of the veins.The ore minerals of gold-bearing quartz vein type gold ore are mainly natural gold,pyrite,chalcopyrite,galena,sphalerite,molybdenite,gangue mineral are quartz and carbonate minerals.The content of molybdenite in deep ore body is increased.The main types of rock alteration include potash,potassium,silicification,pyrite mineralization,silicification and kaolinization,chloritization and greening petrochemical and carbonation,which is the most significant potassium and silicification,gold mineralization is most closely related to silicification and silicification.Mineralization can be divided into five stages,dark red fine-grained quartz-hematite-asphalt uranium ore stage,white veins quartz-potassium feldspar stage,gray veins quartz-pyrite stage,smoke-gray quartzpolymetallic sulphide stage,quartz-calcite-pyrite stage.The gas-liquid inclusions studies have shown that,the ore-forming fluids of the trench gold deposit belong to the CO2-H2O-NaCl system in general,with medium temperature,low salinity(early small amount of high salinity)characteristics.S and Pb isotopic analysis indicated that the ore-forming material originated from the mantle source or mixed with crust-mantle.The Haigou gold deposit is produced in the Late Paleozoic granitic rocks,which should belong to the magmatic hydrothermal medium-temperature gold deposit related to the basic rock mass and the vein rock,and there are some differences compared to the orogenic gold deposits.The Haigou monzonite-monzonitic granite relative enrichment Rb,Ba,K and other large ion lithophile elements(LILE),relative loss of Nb,P,Ti and other high field strength elements(HFSE),(87Sr /86Sr)i is 0.705656~0.705837,?Nd(t)is-10.42~-8.62,the age TDM2 of the two-stage Nd depleted mantle model is 1.84Ga~1.99 G,206Pb/204 Pb is 17.2195~17.4301,207Pb/204 P is 15.4659~15.5212,208Pb/204 Pb is 37.1721~37.6601.Which is a kind of high-kalcium alkaline type I volcanic arc granite formed in the paleoPaleozoic Asian subtraction,and has the characteristics of crust-mantle mixed source.The Shirengou biotite adamellite relative enrichment Rb,Ba,K and other large ion lithophile elements(LILE),Relative loss of Nb,P,Ti and other high field strength elements(HFSE),(87Sr /86Sr)i is 0.70695,?Nd(t)is-13.1,the age TDM2 of the two-stage Nd depleted mantle model is 2.06 Ga,206Pb/204 Pb is 17.5380,207Pb/204 Pb is 15.5240,208Pb/204 Pb is 37.7980.Which belongs to the I-type continental arc granite formed by the subduction of the Mesozoic Pacific plate to the Eurasian plate,and has the characteristics of mixed crust and mantle.The Dahaigou gabbro-diorite relative enrichment Rb,Ba,K,Sr,Hf and other large ion lithophile elements(LILE)and Th,U and other radioactive elements,Relative loss of Nb,P,Ti and other high field strength elements(HFSE),(87Sr /86Sr)i is 0.70465~0.70450,?Nd(t)is 3.8~4.3,the age TDM2 of the two-stage Nd depleted mantle model is 586Ma~ 623 Ma,which is formed in the late Yanshan period from the extrusion orogeny to the extended environment of the era of rock material derived from the mantle,and by crustal mixture.The zircon U-Pb age of the Haigou rock mass is 326.1±2.5Ma,the Shirengou rock mass is 169.7±1.3Ma,the Dahaigou rock mass is 132.6±0.8Ma,the diorite porphyrite is 128±12Ma,the syenodiorite porphyry is 132.4±1.5Ma and the diabase is 131.5±0.5Ma.The comprehensive analysis suggests that the age of the Haigou gold deposit can be limited to between 132.6~128 Ma.Based on the study of magmatic rock associated with the Haigou gold deposits,based on the analysis of ore-forming geological events in the mining area.The metallogenic dynamics background of the Haigou gold deposit is considered that the Pacific plate to the Eurasian plate subduction under conditions under upwelling of asthenospheric mantle,mantle lithosphere thinning,resulting in a series of strong structures,magma and hydrothermal activity. |
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