Abstract:Many hot springs distribution in Tianshui city and Its northern-southern adjacent areas. In this paper, the regional and deep geological background and the geothermal mechanism for the hot spring forming are discussed, based on its geological and geophysical fields analysis. In this region, the tectonic faults with NS direction develop, neutral-acid intrusive rocks and alkaline basalt eruptive rocks form two nearly NS direction magmatic rock belts. In the depth, the rheosphere is some shallower and leithosphere is thiner than other regions, where thermal material from upper mantle gushed up and caused Mohole uplifting. In middle crust both low velocity layer and high conduct layer appear together. On the surface, the thermal current values increase and hot springs distribute as net shape. This region is a favourable exploring region for upliftfracture-convection type geothermal resources in Gansu province.
