松辽盆地地壳热结构与深部热源条件  

Crustal Thermal Structure and Deep Heat Source Conditions in Songliao Basin,NE China

作　　者：张健 何雨蓓 范艳霞 ZHANG Jian;HE Yu-bei;FAN Yan-xia(College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院大学地球与行星科学学院,北京100049

出　　处：《地球科学与环境学报》2023年第2期157-167,共11页Journal of Earth Sciences and Environment

基　　金：国家重点研发计划项目(2021YFA0716002);国家自然科学基金项目(42176052);中国科学院战略性先导科技专项项目(XDB42020104)。

摘　　要：松辽盆地是中国中低温地热能的重点地热资源区。利用最新地震成像资料,结合重、磁、地热观测数据及盆地构造演化与地幔热流关系,计算分析了松辽盆地深、浅地层热量配分比例,莫霍面与居里面深度,盆地生热率结构。结果表明:①松辽盆地浅部地壳的地温场以传导传热为主;②盆地中心莫霍面上隆,但上地幔热流处于衰减回落状态,上地幔供热不足导致莫霍面温度相对周缘要低;③盆地中心居里面较深,与上地幔热松弛相关;居里面之上,受花岗岩较高放射性生热率影响,地温梯度较高;居里面之下,受地幔热流衰减回落影响,地温梯度下降。综上所述,中央坳陷区上地幔处于热流衰减的热松弛阶段,其对地表热流贡献小于上地壳放射性生热对地表热流的贡献,松辽盆地中部地表热异常成因主要是地壳上部的花岗岩放射性生热。The Songliao Basin is a key geothermal resource area for medium and low temperature geothermal energy in China.Using the latest seismic imaging data,combined with the gravity,geomagnetism and geothermal observation data and the relationship between basin tectonic evolution and mantle heat flow,the heat distribution ratio of deep and shallow strata,the depth of Moho surface and Curie surface,and the heat generation rate structure in Songliao Basin were calculated.The results show that①the geothermal field of the shallow crust in Songliao Basin is dominated by conductive heat transfer;②although the Moho surface in the center of the basin is uplifted,the heat flow of the upper mantle is in a state of decay and decline,and the heating of the upper mantle is insufficient,resulting in a relatively low temperature of the Moho surface;③the Curie surface in the center of the basin is deeper,which is related to the thermal relaxation of the upper mantle;above the Curie surface,the geothermal gradient is high due to the higher radioactive heat generation rate of granite;under the Curie surface,the geothermal gradient decreases due to the attenuation and fall of the mantle heat flow.It is considered that the upper mantle in the central depression is in the thermal relaxation stage of heat flow attenuation,and its contribution to the surface heat flow is less than that of the radioactive heat generation in the upper crust.The origin of surface thermal anomaly in the central Songliao Basin is mainly the radioactive heat generation of granite in the upper crust.

关 键 词：地热资源 地壳热结构 放射性生热 上地幔热松弛 居里面 莫霍面 花岗岩 松辽盆地 

分 类 号：P314[天文地球—固体地球物理学]