Distribution characteristics of geothermal water on the northwestern margin of the Xining basin

Abstract：The paper mainly discusses the conditions of occurrence of geothermal water and conceptual model of geothermal reservoir structure in the Nanmenxia-Taizi area, Huzhu County, on the northwestern margin of the Xining basin．The conceptual model of the geothermal reservoir proposed in the paper is as follows：stratigraphic control on the geothermal reservoir-lateral runoff recharge of groundwater-terretrial heat supply-terretrial heat conduction along the deep fault-heat storage in low-thermal conductivity rocks. On that basis, it is concluded that: this geothermal reservoir occurs in marble of the the Neoproterozoic Kesur Formation and sandy conglomerate of the Lower Cretaceous Minhe Formation, lies on a slope zone between the Laoyeshan uplift and Shuangshu depression, shows a geological structure of an “uplift in a depression”, and has good geothermal-geological conditions and certain prospects of geothermal resource exploitation and utilization.