This paper is the result of geothermal survey engineering.

Objective There are two reasons for the formation of surface thermal anomaly: abnormal heat source and abnormal heat transfer mode. The coexistence of "Thick Crust" and "Hot Crust" is the biggest difference between the high temperature geothermal system on the Xizang Plateau and the common convergent plate margin geothermal system.Partial melting (Hotsource) is an abnormal heat source in the "HotCrust", and fracture system (Structure) is a convective heat transfer channel in the "Thick Crust". Clearly depicting the spatial relationship between the two and exploring the structural-thermal coupling model of heat generation may be an important approach to improving the characteristic heat generation theory of the Xizang Plateau under the coexistence of a "Thick crust" and a "Hot crust".

Methods This study takes the Rujiao Boiling Spring in Saga County as an example, and uses magnetotelluric sounding and audio magnetotelluric sounding.

Results To explore the spatial relationship between the fault system and partial melting; we combined with previous studies on geophysics, geochemistry and fluid dynamics, established Rujiao boiling spring structure-thermal couplingthermal model; and set up two production wells with the intersection of the fault system as the target.

Conclusion The Rujiao tectonic-thermal coupled model of heat generation has universal applicability, which is of great significance for improving the formation theory of characteristic heat in the Xizang Plateau and enhancing the success rate of geothermal exploration.