The study of back-arc sedimentary basins is key to understanding oceanic and continental geodynamic processes and mechanisms.The East China Sea Shelf Basin(ECSSB),a back-arc sedimentary basin in a continent-ocean tran...The study of back-arc sedimentary basins is key to understanding oceanic and continental geodynamic processes and mechanisms.The East China Sea Shelf Basin(ECSSB),a back-arc sedimentary basin in a continent-ocean transition zone of the western Pacific Ocean,exhibits remarkable differences in terms of the tectonic deformation characteristics of the basin and the evolutionary features of its sags.These features have led to varied understandings of deep dynamic mechanisms driving the evolution of the basin.In this study,which is based on a detailed interpretation of two-dimensional multichannel seismic data from the ECSSB,the tectonic deformation of the basin is analyzed and the tectonic evolutionary process of the basin is reconstructed.The above research work combines plate convergence processes and deep crust-mantle interactions to explore the controlling factors and deep dynamic mechanisms of the tectonic deformation in the ECSSB.The results of this study indicate that there are significant differences in tectonic deformation between the southern and northern parts of the basin and that the deformation is characterized by eastward migration.Deep crust-mantle interactions are coupled with the development of these differences.The tectonic deformation of the ECSSB is driven by the interactions of the paleo-Pacific,Pacific,Indian,and Philippine Sea Plates with the Eurasian Plate,which have shaped the tectonic pattern of the ECSSB,resulting in east-west zoning,north-south blocking,and pronounced spatiotemporal variability in tectonic deformation.This research provides new insights into the differential development of sags within the ECSSB and provides an important reference for studying back-arc sedimentary basins.展开更多
Recent geophysical research programs survey the Tamu Massif within the Shatsky Rise oceanic plateau in the northwest Pacific Ocean to understand the formation of this immense volcano and to test the forma- tion hypoth...Recent geophysical research programs survey the Tamu Massif within the Shatsky Rise oceanic plateau in the northwest Pacific Ocean to understand the formation of this immense volcano and to test the forma- tion hypotheses of large igneous province volcanism. Massive sheet basalt flows are cored from the Tamu Massif, implying voluminous eruptions with high effusion rates. Seismic reflection data show that the Tamu Massif is the largest single volcano on Earth, characterized by a central volcanic shield with low- gradient flank slopes, implying lava flows emanating from its center and spreading massive area on the seafloor. Velocity model calculated from seismic refraction data shows that crustal thickness has a negative correlation with average velocity, implying a chemically anomalous origin of the Tamu Massif. Seismic refraction and reflection data reveal a complete crustal structure across the entire vol- cano, featured by a deep crust root with a maximum thickness of -30 kin, and Moho geometry is consis- tent with the Airy lsostasy. These recent findings provide evidence for the two end-member formation models： the mantle plume and the plate boundary, Both are supported by some results, but both are not fit with some either. Consequently, plume-ridge interaction could be a resolution that awaits future investigations.展开更多
基金the Laoshan Laboratory(No.LSKJ202203401)the Geological Survey Projects of the China Geological Survey(Nos.DD20221723,DD20243116)+2 种基金the Natural Science Foundation of Shandong Province(No.ZR2023MD047)the Major Basic Research Project of Shandong Province(No.ZR2021ZD09)the National Natural Science Foundation of China(No.42476077)。
文摘The study of back-arc sedimentary basins is key to understanding oceanic and continental geodynamic processes and mechanisms.The East China Sea Shelf Basin(ECSSB),a back-arc sedimentary basin in a continent-ocean transition zone of the western Pacific Ocean,exhibits remarkable differences in terms of the tectonic deformation characteristics of the basin and the evolutionary features of its sags.These features have led to varied understandings of deep dynamic mechanisms driving the evolution of the basin.In this study,which is based on a detailed interpretation of two-dimensional multichannel seismic data from the ECSSB,the tectonic deformation of the basin is analyzed and the tectonic evolutionary process of the basin is reconstructed.The above research work combines plate convergence processes and deep crust-mantle interactions to explore the controlling factors and deep dynamic mechanisms of the tectonic deformation in the ECSSB.The results of this study indicate that there are significant differences in tectonic deformation between the southern and northern parts of the basin and that the deformation is characterized by eastward migration.Deep crust-mantle interactions are coupled with the development of these differences.The tectonic deformation of the ECSSB is driven by the interactions of the paleo-Pacific,Pacific,Indian,and Philippine Sea Plates with the Eurasian Plate,which have shaped the tectonic pattern of the ECSSB,resulting in east-west zoning,north-south blocking,and pronounced spatiotemporal variability in tectonic deformation.This research provides new insights into the differential development of sags within the ECSSB and provides an important reference for studying back-arc sedimentary basins.
基金supported by the National Natural Science Foundation of China (41606069 and 31500411)the Key Laboratory of Marine Mineral Resources, Ministry of Land and Resources of China (KLMMR-2014-B-06)+6 种基金the Key Laboratory of Marginal Sea Geology, Chinese Academy of Sciences (MSGL15-04)the Natural Science Foundation of Guangdong Province in China (2015A030310374)the Ministry of Human Resources and Social Security of China (50603-54)the Key Laboratory for Ecological Environment in Coastal Areas, State Oceanic Administration (201504)the Key Laboratory of Integrated Marine Monitoring and Applied Technologies for Harmful Algal Blooms, State Oceanic Administration (MATHAB201501)the Director Grant for Oceanic technology of South China Sea Branch, State Oceanic Administration (1501)the Mariana Trench Project of the South China Sea Institute of Oceanology, Chinese Academy of Sciences
文摘Recent geophysical research programs survey the Tamu Massif within the Shatsky Rise oceanic plateau in the northwest Pacific Ocean to understand the formation of this immense volcano and to test the forma- tion hypotheses of large igneous province volcanism. Massive sheet basalt flows are cored from the Tamu Massif, implying voluminous eruptions with high effusion rates. Seismic reflection data show that the Tamu Massif is the largest single volcano on Earth, characterized by a central volcanic shield with low- gradient flank slopes, implying lava flows emanating from its center and spreading massive area on the seafloor. Velocity model calculated from seismic refraction data shows that crustal thickness has a negative correlation with average velocity, implying a chemically anomalous origin of the Tamu Massif. Seismic refraction and reflection data reveal a complete crustal structure across the entire vol- cano, featured by a deep crust root with a maximum thickness of -30 kin, and Moho geometry is consis- tent with the Airy lsostasy. These recent findings provide evidence for the two end-member formation models： the mantle plume and the plate boundary, Both are supported by some results, but both are not fit with some either. Consequently, plume-ridge interaction could be a resolution that awaits future investigations.
