Prospect Analysis Of Coal-Carboniferous-Permian In Hunjiang Coalfield

Hunjiang coalfield is located in the southeast of jilin province and has a long history of exploration and development.It belongs to the old mining area,and its coal hunting has always been one of the key tasks in jilin province.The main coal-bearing strata are the upper carboniferous taiyuan formation and the lower Permian shanxi group,and there are a few scattered in Jurassic.HunJiang coalfield special geographical position and coal-bearing strata lithologic composition,structure,coal,building types and the characteristics of coal is different from other parts of north China and north Korea south area,build on is given priority to with coarse clastic sediments,carbonate rock and mudstone sedimentary thickness is significantly lower in east and west area.The hunjiang coalfield on the tectonic partition belongs to the hunjiang taizi river sag in the south of the north China plate,between the longgang uplift and the old ridge uplift.Due to the extruding from the south east to the north west,the zonality of the south to the north was developed,and it was divided into two areas by the fault of the old ridge.West the direction of the coal-bearing formation is the main of the axis of fold structure in the north to the east,and S type distribution,coal bearing strata fracture cutting,complete coal-bearing synclinal basin were cut fracture into syncline.The tectonic stress in the eastern district is weaker than that in the west area,mainly because of a series of shingle fan structures caused by early fold deformation and late thrust,and the coal formation is mainly controlled by syncline.There are three main sedimentary systems of coal-bearing strata: braided river,delta and barrier coast.The braided river sediments were mainly developed in the sun jiagou formation,upper stone box group and lower stone box group.In taiyuan formation and the braided river delta in Shanxi Province,the main development of the barrier beach in benxi group is the barrier island(barrier sand dam),lagoon facies and offshore continental shelf facies.Permo-carboniferous in the area has experienced from the barrier coast to the braided river delta and braided river evolution process,the water exit gradually from northwest to southeast,overall becomes shallow water bodies,sediments derived from the northwest.The coal bearing strata in the original sedimentary period is a whole continuous coal basin,which is mainly composed of continental sedimentary facies.From the middle ordovician to the early carboniferous,the region was raised and suffered a long period of denudation,and the crust subsidence in the upper carboniferous period,and the overall morphology was low in the east and west.Affected by sedimentary lithofacies paleogeographic conditions,the ancient landscape,ancient vegetation,the ancient climate,type of peat swamps,marshes in the depth of the water and geochemical conditions,at this time can let a space to increase rate of balance with the peat accumulation rate,is conducive to the formation of coal seam.The eastern district is mainly composed of continental coal deposits,and the west side is deposited with continental deposits.Late carboniferous period when the earth's crust continue to rise,at this time of the water of the sea has been basically all exits,into the Permian period,the sedimentary facies by interaction of delta plain facies transition for the flood plain and peat swamp facies,formed the second important coal-accumulating period of late Paleozoic.According to the structure,stratigraphic distribution and paleogeographic features of the carboniferous strata in the coal field of hunjiang coal field,it is predicted that the coal direction is the deep strata in A1B1 and A2B2 region.