中国陆地热岩石圈厚度及其地球动力学意义  

The thickness of the thermal lithosphere in China's Mainland and its geodynamic significance

作　　者：陈超强 何丽娟[1,2,3] 焉力文 武金辉 CHEN ChaoQiang;HE LiJuan;YAN LiWen;WU JinHui(State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Institute of Earth Science,Chinese Academy of Sciences,Beijing 100029,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院地质与地球物理研究所岩石圈演化国家重点实验室,北京100029 [2]中国科学院地球科学学院,北京100029 [3]中国科学院大学,北京100049

出　　处：《地球物理学报》2022年第8期3054-3063,共10页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(42074095);国家重点研发计划“变革性技术关键科学问题”重点专项(2021YFA0716002)共同资助.

摘　　要：依靠最新的中国大地热流数据、精细的地壳分层结构,通过求解一维稳态热传导方程获得各个热流测量点对应的热岩石圈厚度,通过克里金插值法绘制中国陆地热岩石圈厚度分布等值线图.计算结果表明,中国陆地各构造区的热岩石圈厚度差异较大,稳定的克拉通地区最厚,可达200 km以上,造山系次之,多在100~200 km之间,破坏的克拉通地区岩石圈最薄,可以低于100 km.通过对比三大克拉通地区的热岩石圈厚度和地震岩石圈厚度,得出了四点认识:(1)塔里木克拉通西部、中上扬子克拉通、华北克拉通西部以及南华北基本保留了稳定的克拉通巨厚岩石圈特征,而华北克拉通东部的渤海湾盆地、下扬子克拉通以及塔里木克拉通东南部则发生了大规模的减薄;(2)华北克拉通西部从鄂尔多斯向东北的银川—河套凹陷及向东南的汾渭凹陷的岩石圈厚度和流变边界层厚度逐渐变薄,主要受控于地幔对流强度的增强;(3)华北克拉通东部的南华北依然保持稳定,而渤海湾的岩石圈厚度减薄显著,体现了华北克拉通破坏在空间上的不均匀性;(4)扬子克拉通自西向东岩石圈厚度和流变边界层厚度逐渐变薄,可能受控于太平洋板块的俯冲,和华北克拉通东部经历了相似的地球动力学过程.Based on the latest heat flow data of China's Mainland and the fine crustal structure data,we calculate the thickness of thermal lithosphere for each heat flow measurement point by solving one-dimensional steady heat conduction equation.The contour map is drawn through Kriging interpolation method and optimized by artificial interpolation and Gaussian filtering.The results show that the thickness of thermal lithosphere varies greatly in different tectonic areas of China.The thermal lithosphere thickness in the stable cratons is the thickest(more than 200 km),followed by that in the orogenic belts(100~200 km).The destructed craton,North China Craton(NCC),has the thinnest thermal lithosphere,which is less than 100 km.By comparing the thickness between thermal lithosphere and seismic lithosphere of the three cratons in China,4 conclusions are obtained as follow:1)The western part of the Tarim craton,the middle-upper Yangtze craton,the western part of the NCC and the southern part of the NCC still remain normal,while the Bohai Bay Basin(the eastern part of NCC),the lower Yangtze craton and the southeastern part of the Tarim craton are thinned significantly;2)In the western NCC,the thickness of thermal lithosphere,seismic lithosphere,and rheological boundary layer all thin from ordos to Yinchuan-Hetao depression in northeast and Fenwei depression in southeast,which is controlled by the mantle convection;3)In the east NCC,the thermal lithospheric thickness of Bohai Bay Basin and the southern part of NCC differs significantly.The thickness of the thermal lithosphere in the southern part of NCC is about 60 km thicker than that in Fenwei depression,even though Fenwei depression is to the west of it and theoretically less influenced by subduction of the Pacific plate.These indicate the variability of the degree of destruction of NCC in different parts;4)The thickness of thermal lithosphere,seismic lithosphere,and rheological boundary layer of the Yangtze craton gradually decrease from west to east,which may be controlled b

关 键 词：热岩石圈 地震岩石圈 流变边界层 克拉通 

分 类 号：P314[天文地球—固体地球物理学]