| The research area is located in Xinbaolige Sumu,Damaoqi,Baotou City,Inner Mongolia Autonomous Region.The geotectonic position is located in the east segment of Langshan-Baiyun Ebo margin depression and in the west of Baiyun Ebo Fold on the northern margin of the North China Platform.The outcrop strata mainly include the Paleoproterozoic Serteng Group,the Mesoproterozoic and Neoproterozoic Baiyun Ebo Group,and the Paleozoic Suji Fm.Magmatic activities are active from the Caledonian period to the Indo-Yanshan period,including especially intensive intermediate-acid magmatism during Variscan and Indo-china period.The minerals in the region are mainly rare earth,iron,gold,graphite and white mica.The Chaganwenduri graphite deposit contains 2 main ore belts.There are 3 graphite ore bodies,occurred in parallel,numbered I,II,and III in the No.1 belt among which the graphite ore body I is the deepest one with the maximum length of 2300m,and the graphite ore body II is the deepest one with the maximum depth of 354.84 m.There are two graphite ore bodies in the No.2 belt.The ore bodies are all found in the graphite-bearing silty sericite slate in the member 1 of the Jianshan Formation(Chj~1).Consisting with the host slat the overall occurrence of layered,nearly layered ore bodies is near NW-SE spreading,inclined to the NE,inclination range from 55°to 64°.According to the result of graphite grain measurement it is shown that the graphite is fine flake in shape with impregnation structure.Being fine flake graphite,it is Accounted for 81.59%that the grains range 1?m to 10?m in diameter.Through the ore processing test,it was found that the graphite ore belongs to the more easily selected ore,and the concentrate ore belongs to the medium carbon graphite.The industrial use is for crucible,refractory and dye.Based on the comparison study on the geological characteristics and ore-forming settings Chaganwenduri graphite deposit,Wudang graphite deposit and the Gaoletu graphite deposit belong to the same type of ore-forming deposit.The mineralized host strata are all belong to the first member of Jianshan Formation of Baiyun Ebo Group,and their source rocks are a assemblage of mudstone,argillaceous silt and other terrigenous clastic rocks rich in aluminum and carboniferous.The carboniferous source is organic.It is presumed to be organics that the carboniferous source come from such as Paleogene blue bacteria(cyanobacteria),eukaryotes and multicellular brown algae.During Neoproterozoic compressional Baiyun Ebo Movement Jianshan Formation of Baiyun Ebo Group underwent the regional metamorphism of the low green schist facies,and the organic matter crystallized to form graphite.In the late stage of the Baiyun Ebo Movement large scale fold was formed.In the early stage of Paleozoic the study area was in extensional regime.Detachment occurred in this region,listric detachment faults were formed,and the Seltenshan Group and the Baiyun Ebo Group uplift to outcrop.Along with the intrusion of the porphyritic biotite monzogranite in the Triassic,the graphite crystallized again under the thermal contact metamorphism,then Chaganwenduri graphite deposit was finally formed.The deposit should belong to microcrystalline graphite deposit due to the superposition of regional metamorphism and thermal contact metamorphism.On the basis of the comprehensive analysis of Metallogenic setting of Chaganwenduri graphite deposit and comparison study on both of Dawudian graphite deposit and Gaoletu graphite deposit,the prospecting graphite deposit model was established.According to this model the target area was determined in the research area.Prospecting engineering verification have been carried out and a large scale crystalline graphite deposit have been newly discovered. |
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