Research On The Ore-controlling Factors And Metallogenic Regularity Of Molybdenum Metallogenic Belt In Chifeng, Eastern Inner Mongolia

Chifeng molybdenum metallogenic belt is located in the east section of the northernorogenic belt of northern margin of North China Craton, is part of Xilamulun metallogenicbelt.Special tectonic background of the study area has a wealth of non-ferrous metalresources,.in recent years the study area have found that several large-mediummolybdenum deposit. on the basis of previous studies, In this paper research the aspects ofseveral typical molybdenum deposit in the district of ore deposit geology、 ore mainelements, trace elements and isotopic dating of surrounding rock, fluid inclusions and soon. And then summarizes the metallogenic belt control output of molybdenum depositore-controlling factors and laws of time and space formed by molybdenum and mineralparagenetic association rule. The main results are as follows:1. genetic types of molybdenum in Chifeng city area are porphyry molybdenumdeposits and hydrothermal vein type molybdenum deposits these two types. in the studyarea, Molybdenum deposit is controled by the nearly EW direction chifeng-kaiyuanfault and NE direction nenjiang fault. The molybdenum deposits in the study area Inchifeng-kaiyuan fault zone linear distribution,In chifeng-kaiyuan fault and NEdirection nenjiang fault where relatively dense deposit distribution. Second level faultscontrol the output form of ore deposit and ore bodies.2. Ore-bearing rock geochemistry indicate Rich ore granite mostly belongs to thehigh silicon, aluminum, aluminum high potassium calc-alkaline series. intrusive rocks which Genetic relationship with molybdenum ore deposit have high total rare earth, lightand heavy rare earth differentiation obvious, rich in light rare earth and large ion lithophileelements, loss of high field strength elements.3.Containing ore rock Zircon U-Pb age show that the diagenesis in the study areaare mainly concentrated in the255-200Ma and150Ma before and after these two periods.Molybdenum mineralization age concentrated in255-200Ma Ma and155-150Ma twostages,180-140ma metallogenic more concentrated. geological facts of the Age of orerock and ore-forming age, reveals the ore-bearing rock contribution to metallogenic is big,may be the ore-forming parent rock.4.Ore-forming fluid study found, Porphyry molybdenum deposit minerals containinggas liquid two phase and Intron mineral3phase of two types of inclusions. From magmaore-forming fluid for high temperature, high salinity and high oxygen fugacity fluid andpart of the magmatic water mixed with tianshui formed in low temperature and lowsalinity of fluid. Hydrothermal vein type molybdenum deposits only development of gasliquid two phase inclusions, Ore fluid has the characteristics of the medium temperatureand medium salinity, Ore-forming fluid has the characteristics of magmatic water andatmospheric water mixing. Porphyry molybdenum deposits mainly formed by themagmatic hydrothermal boiling, Hydrothermal vein type molybdenum deposit mainlycontaining ore fluid and other ore-forming fluid mixing action. Isotope characteristics ofmolybdenite Re shows that molybdenum metal of chifeng district has curtain shell mixedsource and to the characteristics of crust source5.chifeng area Molybdenum metallogenic belt’s ore-controlling geological mainlyincludes Strata, magmatic rocks and structures these3factors. Formation control of themolybdenum deposit mainly about Permian frontal figure in the group and in the northchannel and the Jurassic-cretaceous Series of volcanic rock formation. Magmatic rocksof molybdenum deposit mainly embodied in the control, Part of the magmatic rocks areboth ore rock and ore-forming parent rock and Part of the magmatic rocks is ore rock. Construction control of the molybdenum deposit in Area deep fracture on the control ofmagmatic rock structure，Second Level fault and interlayer fissure is to control theore-controlling structure of the ore body.6.Metallogenic model in the study area is:255-200Ma Ma early stage ofmineralization Thermodynamic from North China-Mongolia plate and Siberia plateimpact extrusion;155-150Ma In the late stage of mineralization Thermodynamic from ThePacific plate to the Asian continent. Fluid metasomatism lithospheric mantle partialmelting of basaltic magma, Within the crust-mantle boundary of assault and bottom invadethe role, The crustal material induced by the earth’s crust material heated by partialmelting, Ore fluid mixed magma evolution. Porphyry molybdenum deposits are mainlydue to the increasing is due to the ore-forming fluid process, Enrichment step by step inthe process of temperature and pressure relief. Hydrothermal vein type molybdenumdeposits are mainly including ore fluid joined by a mixture of atmospheric water,whichseparation and enrichment in hydrothermal ore-forming elements.