HOT DRY ROCKS IN LIAONING PROVINCE: Occurrence Conditions and Primary Selection of Target Areas

As a renewable high-temperature geothermal resource, dry hot rock has received increasing attention in China. The temperature of dry hot rock cannot be measured directly except by deep drilling methods. However, the underground thermal anomalies can be indirectly reflected by the indicators such as terrestrial heat flow, buried depth of Curie surface, distribution of acid rock mass, crust low-velocity and high-conduction zone, as well as tectonic stress field. The high value points of terrestrial heat flow in Liaoning Province are mainly distributed in Liaoyang-Haicheng-Gaizhou region, followed by the western sag of Lower Liaohe Basin. The Curie surface uplift area of the province is distributed around the north Liaoning depression area, with the buried depth of Curie surface at the uplift center above 18 km. The highly radioactive granites are mainly Early Cretaceous granites, distributed in eastern and southern Liaoning regions. There are crust low-velocity and high-conduction zones within about 40 km from the east and west sides of Haicheng area, with the buried depth of 10-20 km. The extensional faults in the area are mainly NE-NEE trending. The Tancheng-Lujiang fault zone is a NE-trending lithospheric fault going through Liaoning Province, and large NE-NEE deep crustal faults are mainly distributed in eastern Liaoning. Based on the analysis of occurrence indexes of hot dry rocks in Liaoning Province and classification of hot dry rock resources in China, the Anshan-Haicheng area is selected as the target of highly radioactive hot dry rock resources, and the Lower Liaohe Basin as the target area of sedimentary basin-type hot dry rock resources.