Abstract:Hongyun water source is located in the north of Jiaxiang fault block. Its main aquifer is middle finegrained dolomite of lower Ordovician Sanshanzi formation. The basic law of karst development in lithology is medium finegrained dolomite > finegrained dolomite > marlite > limestone and leopard skin limestone > microcrystalline dolomite. The regional fault structures are developed, and most of them are extensional faults. The karst development is generally zonal, and the development depth is generally between 143~330m, which is basically consistent with the strike of fault structures, and provide a good place and channel for the accumulation and migration of groundwater. The fluctuation of Ordovician roof provides strong groundwater dynamic conditions for karst groundwater runoff. By studying the characteristics of karst development and comparing with regional geological and hydrogeological conditions, it is confirmed that karst development is related to stratum lithology, geological structures, groundwater dynamic conditions and burial depth. By comparing with the strata data of exploration holes, water rich conditions of Hongyun water source area have been analyzed. The suitable lithology is the material basis of karst development, geological structures are controlling factor of karst development, and the strong circulation of hydrodynamic conditions is the external factor of karst development, which is the basic law of the special enrichment of karst water in Hongyun water source area. It can be used to guide the investigation of buried karst groundwater in Northern China and to find the area of karst water enrichment.
