The Mohorovicic discontinuity(Moho)boundary separating the Earth’s crust and mantle reflects the evolutionary trajectory of the Earth’s crust,yielding crucial insights into crustal formation,tectonic evolution,and p...The Mohorovicic discontinuity(Moho)boundary separating the Earth’s crust and mantle reflects the evolutionary trajectory of the Earth’s crust,yielding crucial insights into crustal formation,tectonic evolution,and profound dynamic processes.However,the prevailing Moho models for China and its adjacent areas suffer from limited accuracy,owing to the irregular and sparse distribution of seismic data collection.In this study,we employ gravimetric data to derive Moho depth,and employ Bott’s regularization method,integrating gravity and seismic data to reconstruct the Moho structure with high precision in a three-dimensional framework across China and its adjacent areas.By optimizing gravity potential field separation and interface inversion techniques,we present a detailed and accurate zoning scheme for classifying China and its adjacent areas into 35 gradient belts,6 primary tectonic units,and 35 secondary tectonic units,based on the spatial distribution characteristics of the Moho discontinuity.Notably,our tectonic pattern division results surpass previous studies in terms of resolution,providing a wealth of tectonic information.Leveraging the Moho depth model of China and its adjacent areas,we discuss orogenic belts,sedimentary basins,fault systems,plate boundaries,and land-sea coupled tectonic patterns.We meticulously summarize the Moho depth distribution characteristics of each tectonic unit,while exploring the macrostructural framework and geological significance of the study area.Our findings highlight the close relationship between China and its adjacent areas Moho depth model and deep geodynamics,elucidating the tectonic evolution both between and within tectonic plates,as well as the tectonic effects induced by mantle dynamics.These insights have crucial implications for the study of deep geodynamics in China and its adjacent areas.展开更多
Mozambique's continental margin in East Africa was formed during the break-off stage of the east and west Gondwana lands. Studying the geological structure and division of continent-ocean boundary(COB) in Mozambiq...Mozambique's continental margin in East Africa was formed during the break-off stage of the east and west Gondwana lands. Studying the geological structure and division of continent-ocean boundary(COB) in Mozambique's continental margin is considered of great significance to rebuild Gondwana land and understand its movement mode. Along these lines, in this work, the initial Moho was fit using the known Moho depth from reflection seismic profiles, and a 3D multi-point constrained gravity inversion was carried out. Thus, highaccuracy Moho depth and crustal thickness in the study area were acquired. According to the crustal structure distribution based on the inversion results, the continental crust at the narrowest position of the Mozambique Channel was detected. According to the analysis of the crustal thickness, the Mozambique ridge is generally oceanic crust and the COB of the whole Mozambique continental margin is divided.展开更多
The gravitational curvatures(GC,the third-order derivatives of the gravitational potential)in gravity field modeling are gaining increased interest in geosciences.The crustal effects of the GC and Moho variation sense...The gravitational curvatures(GC,the third-order derivatives of the gravitational potential)in gravity field modeling are gaining increased interest in geosciences.The crustal effects of the GC and Moho variation sensed by the GC are not fully evaluated for the current study.In this contribution,the effects of the GC induced by topographic and anomalous crustal masses are investigated based on ETOPO1 and CRUST1.0 models using the tesseroids.By adopting the gravitational stripping correction,the residual GC sensed by the CRUST1.0 Moho depths are presented globally to examine whether the GC can sense crustal mass anomalies at the satellite altitude of 260 km.The spatial analysis using the Pearson correlations coefficient(PCC)between the residual GC and the CRUST1.0 Moho depths is performed.Among the 10 residual GC functionals,the PCC value of the residual radial-radial-radial componentδT^(res)_(zzz)is largest with 0.31,where this value is highly dependent on the spectral content removed from the EGM2008,e.g.signals assumed to relate to deeper mass anomalies.Numerical experiments show that with the increased order of the derivatives up to third-order,the fineness level of different global Moho sensed crustal mass anomalies increases correspondingly.Taking the Tibetan plateau for example,the values of theδT^(res)_(zzz)can better reveal the detailed features of the Tibetan plateau’s Moho depth than these of the lower-order residual radial functionals(i.e.disturbing potentialδTres,disturbing radial gravity vectorδT^(res)_(z),and disturbing radial-radial gravity gradient tensorδT^(res)_(zz)),especially for the Qaidam,Sichuan,Tarim,and Turpan basins.Numerical results over the Himalayan region demonstrate that the GC componentδT^(res)^(z)has some potential in geophysical inversion.These residual GC functionals would help to get a better knowledge of the internal structures of the Earth and other planetary objects.展开更多
首先研究了大型沉积盆地对地表重力异常的影响,然后基于Parker-Oldenburg迭代算法,利用经过沉积层改正的布格重力异常数据反演了中国西部的Moho面深度。结果表明,地壳浅层密度异常对地表重力异常和Moho面深度结果的影响较大,利用简化的...首先研究了大型沉积盆地对地表重力异常的影响,然后基于Parker-Oldenburg迭代算法,利用经过沉积层改正的布格重力异常数据反演了中国西部的Moho面深度。结果表明,地壳浅层密度异常对地表重力异常和Moho面深度结果的影响较大,利用简化的三层沉积层模型,计算出的中国西部沉积盆地的重力异常改正最大可达25 m Gal,由此引起的Moho面深度可达2.2 km,Moho面深度最终计算结果与区域最新研究成果相符合,因此,利用重力异常反演Moho面深度时,应考虑沉积层的影响以提高反演精度。展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42474121 and 42192535)the Basic Frontier Science Research Program of the Chinese Academy of Sciences(Grant No.ZDBS-LY-DQC028).
文摘The Mohorovicic discontinuity(Moho)boundary separating the Earth’s crust and mantle reflects the evolutionary trajectory of the Earth’s crust,yielding crucial insights into crustal formation,tectonic evolution,and profound dynamic processes.However,the prevailing Moho models for China and its adjacent areas suffer from limited accuracy,owing to the irregular and sparse distribution of seismic data collection.In this study,we employ gravimetric data to derive Moho depth,and employ Bott’s regularization method,integrating gravity and seismic data to reconstruct the Moho structure with high precision in a three-dimensional framework across China and its adjacent areas.By optimizing gravity potential field separation and interface inversion techniques,we present a detailed and accurate zoning scheme for classifying China and its adjacent areas into 35 gradient belts,6 primary tectonic units,and 35 secondary tectonic units,based on the spatial distribution characteristics of the Moho discontinuity.Notably,our tectonic pattern division results surpass previous studies in terms of resolution,providing a wealth of tectonic information.Leveraging the Moho depth model of China and its adjacent areas,we discuss orogenic belts,sedimentary basins,fault systems,plate boundaries,and land-sea coupled tectonic patterns.We meticulously summarize the Moho depth distribution characteristics of each tectonic unit,while exploring the macrostructural framework and geological significance of the study area.Our findings highlight the close relationship between China and its adjacent areas Moho depth model and deep geodynamics,elucidating the tectonic evolution both between and within tectonic plates,as well as the tectonic effects induced by mantle dynamics.These insights have crucial implications for the study of deep geodynamics in China and its adjacent areas.
基金The National Natural Science Foundation of China under contract No. 42076078China–Mozambique Joint Cruise under contract No. GASI-01-DLJHJ-CM。
文摘Mozambique's continental margin in East Africa was formed during the break-off stage of the east and west Gondwana lands. Studying the geological structure and division of continent-ocean boundary(COB) in Mozambique's continental margin is considered of great significance to rebuild Gondwana land and understand its movement mode. Along these lines, in this work, the initial Moho was fit using the known Moho depth from reflection seismic profiles, and a 3D multi-point constrained gravity inversion was carried out. Thus, highaccuracy Moho depth and crustal thickness in the study area were acquired. According to the crustal structure distribution based on the inversion results, the continental crust at the narrowest position of the Mozambique Channel was detected. According to the analysis of the crustal thickness, the Mozambique ridge is generally oceanic crust and the COB of the whole Mozambique continental margin is divided.
基金supported by National Natural Science Foundation of China[Grant Nos.42030105,41721003,41804012,41631072,41874023].
文摘The gravitational curvatures(GC,the third-order derivatives of the gravitational potential)in gravity field modeling are gaining increased interest in geosciences.The crustal effects of the GC and Moho variation sensed by the GC are not fully evaluated for the current study.In this contribution,the effects of the GC induced by topographic and anomalous crustal masses are investigated based on ETOPO1 and CRUST1.0 models using the tesseroids.By adopting the gravitational stripping correction,the residual GC sensed by the CRUST1.0 Moho depths are presented globally to examine whether the GC can sense crustal mass anomalies at the satellite altitude of 260 km.The spatial analysis using the Pearson correlations coefficient(PCC)between the residual GC and the CRUST1.0 Moho depths is performed.Among the 10 residual GC functionals,the PCC value of the residual radial-radial-radial componentδT^(res)_(zzz)is largest with 0.31,where this value is highly dependent on the spectral content removed from the EGM2008,e.g.signals assumed to relate to deeper mass anomalies.Numerical experiments show that with the increased order of the derivatives up to third-order,the fineness level of different global Moho sensed crustal mass anomalies increases correspondingly.Taking the Tibetan plateau for example,the values of theδT^(res)_(zzz)can better reveal the detailed features of the Tibetan plateau’s Moho depth than these of the lower-order residual radial functionals(i.e.disturbing potentialδTres,disturbing radial gravity vectorδT^(res)_(z),and disturbing radial-radial gravity gradient tensorδT^(res)_(zz)),especially for the Qaidam,Sichuan,Tarim,and Turpan basins.Numerical results over the Himalayan region demonstrate that the GC componentδT^(res)^(z)has some potential in geophysical inversion.These residual GC functionals would help to get a better knowledge of the internal structures of the Earth and other planetary objects.
文摘首先研究了大型沉积盆地对地表重力异常的影响,然后基于Parker-Oldenburg迭代算法,利用经过沉积层改正的布格重力异常数据反演了中国西部的Moho面深度。结果表明,地壳浅层密度异常对地表重力异常和Moho面深度结果的影响较大,利用简化的三层沉积层模型,计算出的中国西部沉积盆地的重力异常改正最大可达25 m Gal,由此引起的Moho面深度可达2.2 km,Moho面深度最终计算结果与区域最新研究成果相符合,因此,利用重力异常反演Moho面深度时,应考虑沉积层的影响以提高反演精度。
