Metallogenic Geological Background And Prospecting Direction In Xiaomoerke Region,the Eastern Slope Of The Northern Great Xing'an Range,NE China

Xiaomoerke region is located in the eastern slope of the north of the Great Xing'an Range,which is in the border zone between the Dayangshu Mesozoic volcanic basin and the granitic complex belt between the ErLian-HeGen mountain fault and the Greater Khingan Range fault.Geotectonic aspects,it belongs to the Siberia plate in Xingan Xingmeng geosyncline terrane in the mid-east region East Zhalantun Dongwuqi volcano type passive continental margin?third tectonic units?in the northern part of Chabaqi-Jiagedaqi Hercynian magmatic complex belt.In addition,In the north of the Great Xing'an Range Baoshan-Arong Qi Mo-Cu-Au metallogenic belt???of molybdenum?copper?ore forming geological condition is superior.Due to the poor geographical conditions of the area,the progress of the work of Geology and mineral resources has been slow,and the formation of mineral resources has not been found.In order to find out the potential of mineral resources in the region,the geological survey of China,we set up the area of 1:5 million geological and mineral resources survey in 12 th Five-Year?2012-2015?.In the process of the work,Select Xiaomoerke region which is benefit for metallogenic,we based on the investigation carried out mineral prospecting work,detailed to study the geological,geophysical and geochemical exploration,remote sensing and mineral comprehensive information system analysis of molybdenum?copper?mineralization delineation and prospecting target area selection,summarize the metallogenic regularity and model,in order to further geological and prospecting direction.?1?Regional geological survey revealed that the region's stratigraphic assemblage are mainly Cretaceous Yiliekede formation?K1y=±123.8Ma?and Quaternary sediments.The Carboniferous alkaline granites?348.9 ± 2.1Ma?,monzonitic granite?310.5 ± 1.3Ma?and the Early Cretaceous biotite monzonitic granite?138.0 ± 1.4Ma?,monzonitic-quartz monzonitic porphyry?120.8 ± 1.1Ma?and alkaline granite porphyry?120.4 ± 1.2Ma?are the main intrusive rock body in the studied area.Early Cretaceous monzonite porphyry?130.6 ± 0.74Ma?.Among the monzonitic-quartz monzonitic porphyry porphyry is closely related to mineralization in this area;Through geological mapping and remote sensing interpretation,the faulted system of the studied area is composed of NE,NW,EW and nearly SN faults,and they are the secondary faults regional faults which constitute the basic frame of the working area is formed.The secondary tensional NNE trending fault structure is closely related to mineralization.?2?Based on 1:50000 stream sediment survey,It delineated 26 multi element composite anomalies,of which there are 10 obvious abnormal element assemblage.The most significant abnormal element assemblage is W-Bi,Mo-Zn-Pb and Ag-Au-Sb,which are combined with the characteristics of superposition and symbiosis.And mineralization has a direct relationship with the higher level of Mo.From the aspect of Geophysics.?3?The geophysical exploration shows that the anomalous area with the anomalous characteristics of the above combined elements has obvious positive anomaly field of the positive pole,and is a favorable area for the occurrence of the ore body.?4?The trenching engineering verification revealed,the main types of mineralization in this area are: molybdenum pyrite ore and silicified altered rock.Mineralization stage can be divided into potassic alteration-beresitization-Pyrite ivory quartz stage-Pyrite-gray pyrite-milky quartz stage.Test results show,Mo grade value is up to 116.7×10^-6330×10^-6 or 0.02%⁰.03%?Mo marginal grade?0.02%⁰.04%?,moreover,Bi content reached 222.32×10^-6,proximity bismuth ore?Bi marginal grade:?0.05⁰.10?×10-2,minimum industrial grade?0.10 0.20?×10-2?.It is revealed that the ore vein of the pyrite ore should be the mineralized site of the bismuth bearing molybdenum ore..Based on the study of comprehensive information of 1:5 million mineralization in Xiaomoerke region,Analysis of the effective metallogenic geological characteristics,geophysical,geochemical and remote sensing interpretation of metallogenic prediction information,atotal of 2 metallogenic prospective zones were identified and combined with the prospecting potential evaluation in the prospective area,2 prospecting target areas are finally selected.One is the mineralized target area of the bismuth ore and the bismuth ore in the vein of pyrite,the other is the target area of hydrothermal molybdenum ore.Mineralization is closely related to the early Cretaceous volcanic rocks and the two long porphyry quartz two longest porphyry.The secondary tensional NNE trending fracture structure in this area is a advantageous space for mineralization.Than combined with the characteristics of typical ore deposits,summarized the metallogenic alteration and prospecting marks,in order to provide a scientific basis for the prospecting potential and prospecting direction of this area.