Occurrence and Development of Deep Underground Water in Hexi Corridor

To the available acievements and exploration data,w divide underground water of Hexi corridor into five stratiform water-bearing rock group,which are Early Palaeozoic group,Carbo niferous-Permian, Triassic-Jurassic,Cretaceous-old Tertiary,and new Tertiary-down pleist ocene series of Quaternary, discussed different aquifers'geological structure,rock character,depth,regularities of distribution,bury character,water abundance,and hydrogeo-chemistry character for each.In addition,we analyzed the geological framework and hydrogeologic condition of the aquifers belong to new Tertiary-down Pleisto ceneseries of Quaternary,divided the aquifer into piedm ont fold zone,middle incline zone,and monocline zone three water-storedtect onic zone,from south to north.So we hold that the supply of the deep groundwater is from the water in the shelf crevice which under the hydrological cutting net of Qilianshan mountainous district.Because the effect of the to pograph and the gravitation,according to the large and deep groundwater circulatory system,the groundwater is transported to the deep part of the basin.However, because the water circulatory system's depth is more than thousands of meters even more dozens of kilometers,the ground water flows slowly,the age of the deep groundwater's supply may keep 800-1 000 years.In the Cretaceous,old Tertiary and new Tertiary-down pleistocene forms the geotherm,making the water tem perature reach 60-70℃ and the water out put of a single well reach 500-800m³/d.