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利用远震数据接收函数H-?叠加和前人发表的共823个台站下方的Moho面深度与平均泊松比信息,结合地形与接收函数振幅资料,共同约束华北克拉通的地壳结构特征.结果表明华北克拉通古老和改造的地壳共存,与区域地形和地质构造有较好的对应关系.华北东、中和西三块体地壳结构差异明显,整体大致处于重力均衡状态,中西部局部地区和东部均衡度较低.它们的平均Moho面深度分别为33,37和42 km,而平均泊松比分别为0.268,0.267和0.264.Moho面深度或泊松比异常主要分布在裂陷区,中部南北缘以及构造边界附近;鄂尔多斯核心表现出典型克拉通性质的Moho面深度和泊松比.三个区域Moho面深度与泊松比都呈现出负相关的关系,但变化趋势存在差异.东、中部北缘接收函数振幅相对较大,裂陷及其邻区振幅相对偏低,燕山带和山西裂陷南侧振幅显示出小尺度变化.上述结果表明,华北东部地壳整体受到破坏减薄,中、西部地壳表现为局部改造.不同区域地壳结构的差异可能反映了华北地壳改造过程和机制的区域差异性:东部地壳整体破坏可能主要由中新生代以来东侧太平洋板块俯冲引起;中、西部地壳局部改造可能是其自身结构和性质的不均匀性在长期演化过程中多次改造活化的叠加效果.
The crustal structure characteristics of North China Craton are constrained by using H-? Superposition of teleseismic data reception function and the Moho depth and average Poisson’s ratio information of 823 stations previously published, combined with the terrain and receiver function amplitude data. The results show that the coexistence of ancient and remodeled crust in North China Craton is in good correspondence with the regional topography and geological structure.The crustal structure of the East, Central and West Three blocks in North China is obviously different and the whole is roughly in the state of gravity balance. The average Moho depth is 33, 37 and 42 km, respectively, while the average Poisson’s ratios are 0.268, 0.267 and 0.264, respectively.The Moho depth or Poisson’s ratio anomaly mainly distributes in the rifting area, Ordos core shows Moho surface depth and Poisson’s ratio of typical craton properties.The depth of Moho surface shows a negative correlation with Poisson’s ratio in the three regions, The amplitudes of the receiver function in the northern part of the central China are relatively large, and the amplitudes of the rifts and its neighboring regions are relatively low. The amplitudes at the south of the Yanshan belt and the Shanxi rift show small-scale changes. The above results show that the North China The overall crustal crust is destroyed and thinned, and the crust in the middle and western parts shows partial transformation.The difference in crustal structure in different regions may reflect the regional differences in crustal reconstruction process and mechanism in North China: the whole crustal damage in the east may be mainly caused by the east side of Mesozoic-Cenozoic The subduction of the Pacific plate resulted in the partial reformation of the crust in the middle and western parts of the world. This may be due to the superposition effect of multiple alteration and activation in the long-term evolution of inhomogeneity of its own structure and properties.