Abstract:
Based on the deep exploration data in phosphate ore in recent years, the authors in this research studied the geological conditions and geothermal characteristics of Xifeng hot spring in Guizhou, and put forward new understandings of geological genesis. ① The imbricate thrust-nappe tectonic system is composed of Yangshui Anticline, Anqing Fault(F
1) and Wenquan Fault(F
2), which constitute the main body and boundary of Xifeng hot spring geothermal water system. The surface structure and internal structure of this geothermal structure system is heterogeneous. And the new strata are covered by the old strata, which consist many overlapped thermal storage units, and these thermal storage units become good places for the formation and migration of geothermal water. ② A series of geothermal storage units are directly contacted by Anqing Fault (F
1), and these units have close hydraulic contact, which provides good channel for water and heat. Wenquan Fault (F
2) forms the geothermal water boundary of Xifeng hot spring. ③ The atmospheric precipitation penetrates into the deep carbonate reservoir along the fracture channel, and it becomes geothermal water after the absorption of heat. Under high temperature and high pressure conditions, the geothermal water continuously migrates to the core of Yangshui Anticline, which is preserved by the overlying strata of Cambrian clastic rocks and limited by the hot spring fault. Then the geothermal water forms a favorable geothermal resource enrichment area in the west wing and north end of Yangshui Anticline, and then is blocked by faults and exposed to the surface.