Division Of Hydrogeological Units In Huainan Coalfield

Huainan coalfield is the major coal production base in coastal China, tectonic elemen belong to deposition of coal basin in Yu-Huai depression of the north China plate,the formation was transformaed by tectonic movement,structures in the area are well developed,the rock mass engineering mechanical properties is poor,suffering from all kinds of flooding infringement.According to the north-south of flushes latitudinal fault zones,Huainan coalfield was divided three hydrogeological unit, Fufeng fracture and Shangtang-Minglongshan fault are the boundary.With the development of utilization of water resources in Huainan area and the demand of release deep coal resource increased steadily,the old partition schemeis too simple and one-sided to meet the development of water resources and the demand of mine water flooding prevention and cure.The Huainan coalfield hydrogeological unit division and regional hydrogeological map compilation,looking forward to make the partition scheme can better reflect the hydrogeological characteristics of Huainan area and provide the basis for the development and utilization of regional water resources and the prevention and control of mine flood.Huainan area at thrust nappe leading peak zone of north China plate,where developing large-scale water blocking faults in NS-trending,the hydrogeology characteristics of these different sides faults has obvious difference.The large-scale water control fracture as the main partition factors,which is same with the intention of old partition scheme,in addition,the new scheme take the regional differences of water blocking faults on both sides of the hydrogeological characteristics consider.Fufeng thrust fault to the south of the thrust nappe system foreland position,stratum structureis extremely complex, so different regional hydrogeological conditions vary widely,such as Cambrian limestone is outcropping in some areas of the Huainan old mining,which directly accept water from lateral recharge unconsolidated layers adjacent area and atmospheric precipitation,where can format cone of depression.The area bedrock is the Archaeozoic gneiss,the vertical recharge path which unconsolidated layers provide water for autochthonous system is open,with large amount of water etc.Bedrock which is covered with thick loose layer in the north of Fufeng thrust fault, thickness of losses bed and character of the fourth aquifer can basically determine condition of bedrock aquifer recharge.Based on geological structure,stratum condition,recharge runoff discharge conditions,hydrodynamic conditions and hydrochemistry field multi factor comprehensive consideration,the new scheme for division of hydrogeological unit in Huainan area is three-level,the primary hydrogeological unit is basis on regional water-controlling structure,which is South,Central and North.Secondary hydrogeological unit has three regions, which are unconsolidated layers covered area, nappe area and recharge limestone area.Tertiary hydrogeological unit has four regions,which are"Red beds"covered area,the fourth aquifer of the Quarternary recharge area,the third aquifuge of the Quarternarycovered area and another aquifer covered area.Nappe area has nappe gneiss area,nappe limestone area,nappe coal measure strata.Recharge limestone area has exposed limestone area and unconsolidated layers recharge limestone area.