GEOTHERMAL RESOURCES AND CRUSTAL THERMAL STRUCTURE OF THE QINGHAI-TIBET PLATEAU

The Qinghai-Tibet Plateau has a unique crustal structure and a high-heat background.The Himalaya terrane in the south is of "hot crust-cold mantle" type and the Lhasa-Gangdise terrane is of "hot crust-hot mantle" type.There is a low-velocity,high-conductivity layer in the middle crust under the region,which is probably a partially molten magma pocket,forming a gigantic geothermal zone.The hydrothermal activity zone of the plateau is mainly exposed between the Himalaya and Gangdise-Nyainqêntanglha.There are 283 hydrothermal areas with temperatures >25℃ and nearly 40 boiling and hot springs with temperatures >80℃.In the famous Yangbajain high-temperature reservoir geothermal field a geothermal power station with an electricity-installed capacity of 25.18 MW has been built,which supplies vast amount of electric power to Lhasa.The geothermal resources occupy an important position in the energy structure on the plateau and have great development prospects and value.