An analysis of trace elements and isotopic geochemistry suggest that the ore-forming materials of gold deposits in the Jiaodong granite-greenstone belt have multiple sources, especially the mantle source. Seismic wave...An analysis of trace elements and isotopic geochemistry suggest that the ore-forming materials of gold deposits in the Jiaodong granite-greenstone belt have multiple sources, especially the mantle source. Seismic wave, magnetic and gravity fields show that the crust-mantle structure and its coupling mechanism are the fundamental dynamic causes for the exchange and accumulation of materials and energy in the metallogenic system. Considering the evolution history of the structural setting, the tectono-metallogenic dynamics model of the area can be summarized as follows: (1) occurrence of the greenstone belt during the Archean-Proterozoic-the embryonic form of Au-source system; (2) stable tectonic setting in the Paleozoic-an intermittence in gold mineralization; (3) intensive activation and reformation of the greenstone belt in the Mesozoic-tectono-mineralization and tectono-diagensis; (4) posthumous structural activity in the Cenozoic-destruction of orebodies in the later stage. In the middle and late Indosinian, the Tancheng-Lujiang fault zone cut deeply into the upper mantle so that the ore-bearing fluids migrated to higher layers through the crust-mantle interaction, resulting in alteration and mineralization.展开更多
The Mongolian Plateau in Central Asia is an intracontinental tectonic system far from active plate boundaries.Despite its distance from these boundaries,the plateau is characterized by intense crustal deformation acco...The Mongolian Plateau in Central Asia is an intracontinental tectonic system far from active plate boundaries.Despite its distance from these boundaries,the plateau is characterized by intense crustal deformation accompanied by voluminous Cenozoic volcanism and active modern seismicity.However,the intraplate deformation mechanism has long been debated owing to the scarcity of observations and contradictions between different results.In recent years,growing geophysical studies have been conducted on the Mongolian Plateau,providing constraints on its lithospheric structure and dynamics.Here,we review the geophysical research on the Mongolian Plateau over the last decade,including seismological,geodetic,gravity,magnetotelluric,and geodynamic aspects.This review aims to(a)describe crustal and mantle structures based on multiscale seismic images;(b)describe deformation patterns based on seismic anisotropy,focal mechanisms,and global positioning system(GPS)observations;and(c)discuss the mechanisms behind intraplate deformation,volcanism,and seismic activity across the Mongolian Plateau.Seismic images show that the crustal structure of the plateau has significant east-west differences.Several blocks in the western Mongolian Plateau have thick crusts,including the Altai Mountains,Hovsgol Rift,and Hangay Dome.The lithospheric deformation across the Mongolian Plateau has strong lateral variation,with NE-SW shortening in the Altai Mountains and W-E or NW-SE shear deformation in the Hangay Dome region and the eastern part.The varied deformation may result from the superposition of multiple mechanisms,including far-field stress in the Altai Mountains,mantle upwelling,and mantle flow in the Hangay Dome region.However,it is difficult to identify the geodynamics of the formation of the entire Mongolian Plateau because the deformation is too complicated,and the present models are not sufficient and are always partial.Overall,this review encompasses recent advances in seismic observations of the Mongolian Plateau,illuminates the h展开更多
为系统、深入地研究中国西部盆(盆地)、山(山脉)、原(高原)的壳幔结构与深部动力学过程,2003年我们提出并领导实施了“羚羊计划”(ANTILOPE-Array Network of Tibetan International Lithospheric Observation and Probe Experiments),...为系统、深入地研究中国西部盆(盆地)、山(山脉)、原(高原)的壳幔结构与深部动力学过程,2003年我们提出并领导实施了“羚羊计划”(ANTILOPE-Array Network of Tibetan International Lithospheric Observation and Probe Experiments),在青藏高原先后完成了羚羊-I(ANTILOPE-I)到羚羊-IV(ANTILOPE-IV)4条二维宽频带台阵剖面,而在青藏高原东西构造结则实施了羚羊-V和羚羊-VI两个三维宽频带台阵探测。另外,我们将前期在准噶尔盆地、天山造山带、塔里木盆地、阿尔金造山带和柴达木盆地开展的九条综合地球物理观测剖面也纳入羚羊计划的总体框架中来。通过“羚羊计划”的实施,我们在中国西部(包括西北部的环青藏高原盆山体系以及西南部的青藏高原)取得了大量的、高质量的、综合的第一手观测数据,获得了中国西部盆、山、原精细的壳幔结构,系统地揭示了中国西部盆山原的深部地球动力学过程。主要结论总结如下:确定了准噶尔盆地基底的结构与属性,优化了盆地的基底构造格架;建立了天山造山带“层间插入削减”新的陆内造山模式,揭示了印欧碰撞在天山岩石圈缩短44%的去向以及由洋陆俯冲到陆陆碰撞俯冲的转换机制;揭示了塔里木盆地、阿尔金造山带和柴达木盆地的盆山接触关系;获得了塔里木盆地顺时针旋转的深部几何学、运动学和动力学证据;确定了青藏高原之下印度板块与欧亚板块的碰撞边界;发现目前的青藏高原由南部的印度板块、北部的欧亚板块和夹持于二者之间的巨型破碎区——西藏“板块”构成,首次确定了各自的岩石圈底边界;修正了高原变形的两个端员模型;建立了深部构造对地表地形的制约关系;系统地揭示了印度板块沿喜马拉雅造山带俯冲的水平距离与俯冲角度的变化规律与控制因素。“羚羊计划”以其巨大的观测网络与综合地球物理探测技术,采用展开更多
基金This study is supported jointly by the National Natural Science Foundation of China(No.40172036)"the Key Project of Science and Technology Research"(No.01037)+1 种基金the“Trans-century Training Program for Outstanding Talents”Fund sponsored by the Ministry of Educationthe National Important Basic Research and Development Planning Program(No.1999043206).
文摘An analysis of trace elements and isotopic geochemistry suggest that the ore-forming materials of gold deposits in the Jiaodong granite-greenstone belt have multiple sources, especially the mantle source. Seismic wave, magnetic and gravity fields show that the crust-mantle structure and its coupling mechanism are the fundamental dynamic causes for the exchange and accumulation of materials and energy in the metallogenic system. Considering the evolution history of the structural setting, the tectono-metallogenic dynamics model of the area can be summarized as follows: (1) occurrence of the greenstone belt during the Archean-Proterozoic-the embryonic form of Au-source system; (2) stable tectonic setting in the Paleozoic-an intermittence in gold mineralization; (3) intensive activation and reformation of the greenstone belt in the Mesozoic-tectono-mineralization and tectono-diagensis; (4) posthumous structural activity in the Cenozoic-destruction of orebodies in the later stage. In the middle and late Indosinian, the Tancheng-Lujiang fault zone cut deeply into the upper mantle so that the ore-bearing fluids migrated to higher layers through the crust-mantle interaction, resulting in alteration and mineralization.
基金National Key Research and Development Program of China(Nos.2022YFF0800601 and 2022YFF0800701)Special Fund of the Institute of Geophysics,China Earthquake Administration(No.DQJB21B32).
文摘The Mongolian Plateau in Central Asia is an intracontinental tectonic system far from active plate boundaries.Despite its distance from these boundaries,the plateau is characterized by intense crustal deformation accompanied by voluminous Cenozoic volcanism and active modern seismicity.However,the intraplate deformation mechanism has long been debated owing to the scarcity of observations and contradictions between different results.In recent years,growing geophysical studies have been conducted on the Mongolian Plateau,providing constraints on its lithospheric structure and dynamics.Here,we review the geophysical research on the Mongolian Plateau over the last decade,including seismological,geodetic,gravity,magnetotelluric,and geodynamic aspects.This review aims to(a)describe crustal and mantle structures based on multiscale seismic images;(b)describe deformation patterns based on seismic anisotropy,focal mechanisms,and global positioning system(GPS)observations;and(c)discuss the mechanisms behind intraplate deformation,volcanism,and seismic activity across the Mongolian Plateau.Seismic images show that the crustal structure of the plateau has significant east-west differences.Several blocks in the western Mongolian Plateau have thick crusts,including the Altai Mountains,Hovsgol Rift,and Hangay Dome.The lithospheric deformation across the Mongolian Plateau has strong lateral variation,with NE-SW shortening in the Altai Mountains and W-E or NW-SE shear deformation in the Hangay Dome region and the eastern part.The varied deformation may result from the superposition of multiple mechanisms,including far-field stress in the Altai Mountains,mantle upwelling,and mantle flow in the Hangay Dome region.However,it is difficult to identify the geodynamics of the formation of the entire Mongolian Plateau because the deformation is too complicated,and the present models are not sufficient and are always partial.Overall,this review encompasses recent advances in seismic observations of the Mongolian Plateau,illuminates the h
文摘为系统、深入地研究中国西部盆(盆地)、山(山脉)、原(高原)的壳幔结构与深部动力学过程,2003年我们提出并领导实施了“羚羊计划”(ANTILOPE-Array Network of Tibetan International Lithospheric Observation and Probe Experiments),在青藏高原先后完成了羚羊-I(ANTILOPE-I)到羚羊-IV(ANTILOPE-IV)4条二维宽频带台阵剖面,而在青藏高原东西构造结则实施了羚羊-V和羚羊-VI两个三维宽频带台阵探测。另外,我们将前期在准噶尔盆地、天山造山带、塔里木盆地、阿尔金造山带和柴达木盆地开展的九条综合地球物理观测剖面也纳入羚羊计划的总体框架中来。通过“羚羊计划”的实施,我们在中国西部(包括西北部的环青藏高原盆山体系以及西南部的青藏高原)取得了大量的、高质量的、综合的第一手观测数据,获得了中国西部盆、山、原精细的壳幔结构,系统地揭示了中国西部盆山原的深部地球动力学过程。主要结论总结如下:确定了准噶尔盆地基底的结构与属性,优化了盆地的基底构造格架;建立了天山造山带“层间插入削减”新的陆内造山模式,揭示了印欧碰撞在天山岩石圈缩短44%的去向以及由洋陆俯冲到陆陆碰撞俯冲的转换机制;揭示了塔里木盆地、阿尔金造山带和柴达木盆地的盆山接触关系;获得了塔里木盆地顺时针旋转的深部几何学、运动学和动力学证据;确定了青藏高原之下印度板块与欧亚板块的碰撞边界;发现目前的青藏高原由南部的印度板块、北部的欧亚板块和夹持于二者之间的巨型破碎区——西藏“板块”构成,首次确定了各自的岩石圈底边界;修正了高原变形的两个端员模型;建立了深部构造对地表地形的制约关系;系统地揭示了印度板块沿喜马拉雅造山带俯冲的水平距离与俯冲角度的变化规律与控制因素。“羚羊计划”以其巨大的观测网络与综合地球物理探测技术,采用
