辽宁省干热岩资源赋存条件分析及靶区初选

干热岩作为一种可再生的高温地热资源, 在我国越来越受到重视.干热岩温度除深部钻探手段外无法直接测量, 但是可以通过大地热流、居里面埋深、酸性岩体分布、壳内低速高导体及构造应力场等指标间接反映地下的热异常.辽宁省大地热流值高值点主要分布于辽阳-海城-盖州一带, 其次为下辽河盆地西部凹陷.辽宁省居里面隆起区绕辽北拗陷区呈环状分布, 隆起中心居里面埋深均在18 km以浅.高放射性花岗岩主要为早白垩世花岗岩, 主要分布于辽东及辽南地区.海城东西两侧约40 km范围内存在壳内低速高导体, 埋深10~20 km.区内张性断裂以NE-NEE向为主, 郯庐断裂带为贯穿辽宁省的NE向岩石圈断裂, 大型NE-NEE深壳断裂主要分布于辽东地区.通过对辽宁省干热岩资源赋存指标的分析, 结合中国干热岩资源的分类, 初选出鞍山-海城一带作为高放射性干热岩资源靶区及下辽河盆地作为沉积盆地型干热岩资源靶区.

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.