The study“Archean cratonic mantle recycled at a mid-ocean ridge”on abyssal peridotites from the Southwest Indian Ridge(SWIR)[1]has received wide attention,which may challenge our Africa continental rift at∼135 Ma a...The study“Archean cratonic mantle recycled at a mid-ocean ridge”on abyssal peridotites from the Southwest Indian Ridge(SWIR)[1]has received wide attention,which may challenge our Africa continental rift at∼135 Ma and the subsequent opening/growth of the South Atlantic Ocean(Fig.1b).That is,the eastward Nazca plate subduction beneath South America and E-mail address:yaoling.niu@foxmail.com(Y.Liu).展开更多
Mantle plumes from deep Earth's interior play a significant role in mantle convection and plate tectonics.Their impact on oceanic lithosphere is invoked to initiate oceanic subduction and modern plate tectonics in...Mantle plumes from deep Earth's interior play a significant role in mantle convection and plate tectonics.Their impact on oceanic lithosphere is invoked to initiate oceanic subduction and modern plate tectonics in the early Earth.They may also contribute to the rifting and break-up of continents and follow oceanic spreading to form open ocean basins during the early stage of the Wilson cycle in the Phanerozoic[1,2].In present-day ocean basins,longlived mantle plume activities coupled with plate motions are supposed to leave spectacular age-progressive trails of intraplate magmatism,such as the 6000-km Emperor-Hawaian volcanic seamount chain across the Pacific plate.展开更多
Modern oceans contain large bathymetric highs(spreading oceanic ridges,aseismic ridges or oceanic plateaus and inactive arc ridges)that,in total,constitute more than 20–30%of the total area of the world’s ocean floo...Modern oceans contain large bathymetric highs(spreading oceanic ridges,aseismic ridges or oceanic plateaus and inactive arc ridges)that,in total,constitute more than 20–30%of the total area of the world’s ocean floor.These bathymetric highs may be subducted,and such processes are commonly referred to as ridge subduction.Such ridge subduction events are not only very common and important geodynamic processes in modern oceanic plate tectonics,they also play an important role in the generation of arc magmatism,material recycling,the growth and evolution of continental crust,the deformation and modification of the overlying plates,and metallogenesis at convergent plate boundaries.Therefore,these events have attracted widespread attention.The perpendicular or high-angle subduction of mid-ocean spreading ridges is commonly characterized by the occurrence of a slab window,and the formation of a distinctive adakite–high-Mg andesite–Nb-enriched basalt-oceanic island basalt(OIB)or a mid-oceanic ridge basalt(MORB)-type rock suite,and is closely associated with Au mineralization.Aseismic ridges or oceanic plateaus are traditionally considered to be difficult to subduct,to typically collide with arcs or continents or to induce flat subduction(low angle of less than 10°)due to the thickness of their underlying normal oceanic crust(>6–7 km)and high topography.However,the subduction of aseismic ridges and oceanic plateaus occurred on both the western and eastern sides of the Pacific Ocean during the Cenozoic.On the eastern side of the Pacific Ocean,aseismic ridges or oceanic plateaus are being subducted flatly or at low angles beneath South and Central American continents,which may cause a magmatic gap.But slab melting can occur and adakites,or an adakite–high-Mg andesite–adakitic andesite–Nb-enriched basalt suite may be formed during the slab rollback or tearing.Cu-Au mineralization is commonly associated with such flat subduction events.On the western side of the Pacific Ocean,however,aseismic ridges and oceanic plateaus are subducted at relatively high angles(>30°).These subduction processes can generate large scale eruptions of basalts,basaltic andesites and andesites,which may be derived from fractional crystallization of magmas originating from the subduction zone fluid-metasomatized mantle wedge.In addition,some inactive arc ridges are subducted beneath Southwest Japan,and these subduction processes are commonly associated with the production of basalts,high-Mg andesites and adakites and Au mineralization.Besides magmatism and Cu-Au mineralization,ridge subduction may also trigger subduction erosion in subduction zones.Future frontiers of research will include characterizing the spatial and temporal patterns of ridge subduction events,clarifying the associated geodynamic mechanisms,quantifying subduction zone material recycling,establishing the associated deep crustal and mantle events that generate or influence magmatism and Cu-Au mineralization,establishing criteria to recognize pre-Cenozoic ridge subduction,the onset of modernstyle plate tectonics and the growth mechanisms for Archean continental crust.展开更多
基金supported by the National Natural Science Foundation of China(91958215,91014003,41130314,41630968,and U1606401)Shandong Basic Research Office(WSR2023018)the Ministry of Education 111 Project(B18048)。
文摘The study“Archean cratonic mantle recycled at a mid-ocean ridge”on abyssal peridotites from the Southwest Indian Ridge(SWIR)[1]has received wide attention,which may challenge our Africa continental rift at∼135 Ma and the subsequent opening/growth of the South Atlantic Ocean(Fig.1b).That is,the eastward Nazca plate subduction beneath South America and E-mail address:yaoling.niu@foxmail.com(Y.Liu).
基金supported by the National Natural Science Foundation of China(91955202 and 42102042)the China Postdoctoral Science Foundation(2021M700198)。
文摘Mantle plumes from deep Earth's interior play a significant role in mantle convection and plate tectonics.Their impact on oceanic lithosphere is invoked to initiate oceanic subduction and modern plate tectonics in the early Earth.They may also contribute to the rifting and break-up of continents and follow oceanic spreading to form open ocean basins during the early stage of the Wilson cycle in the Phanerozoic[1,2].In present-day ocean basins,longlived mantle plume activities coupled with plate motions are supposed to leave spectacular age-progressive trails of intraplate magmatism,such as the 6000-km Emperor-Hawaian volcanic seamount chain across the Pacific plate.
基金supported by the National Natural Science Foundation of China(Grant Nos.41630208 and 91855215)the National Key R&D Program of China(Grant No.2016YFC0600407)+3 种基金the Strategic Priority Research Program(A)of the Chinese Academy of Sciences(Grant No.XDA2007030402)the Key Program of the Chinese Academy of Sciences(Grant No.QYZDJ-SSWDQC026)the Key Program of Guangzhou City(Grant No.201707020032)No.IS-2873 from GIGCAS。
文摘Modern oceans contain large bathymetric highs(spreading oceanic ridges,aseismic ridges or oceanic plateaus and inactive arc ridges)that,in total,constitute more than 20–30%of the total area of the world’s ocean floor.These bathymetric highs may be subducted,and such processes are commonly referred to as ridge subduction.Such ridge subduction events are not only very common and important geodynamic processes in modern oceanic plate tectonics,they also play an important role in the generation of arc magmatism,material recycling,the growth and evolution of continental crust,the deformation and modification of the overlying plates,and metallogenesis at convergent plate boundaries.Therefore,these events have attracted widespread attention.The perpendicular or high-angle subduction of mid-ocean spreading ridges is commonly characterized by the occurrence of a slab window,and the formation of a distinctive adakite–high-Mg andesite–Nb-enriched basalt-oceanic island basalt(OIB)or a mid-oceanic ridge basalt(MORB)-type rock suite,and is closely associated with Au mineralization.Aseismic ridges or oceanic plateaus are traditionally considered to be difficult to subduct,to typically collide with arcs or continents or to induce flat subduction(low angle of less than 10°)due to the thickness of their underlying normal oceanic crust(>6–7 km)and high topography.However,the subduction of aseismic ridges and oceanic plateaus occurred on both the western and eastern sides of the Pacific Ocean during the Cenozoic.On the eastern side of the Pacific Ocean,aseismic ridges or oceanic plateaus are being subducted flatly or at low angles beneath South and Central American continents,which may cause a magmatic gap.But slab melting can occur and adakites,or an adakite–high-Mg andesite–adakitic andesite–Nb-enriched basalt suite may be formed during the slab rollback or tearing.Cu-Au mineralization is commonly associated with such flat subduction events.On the western side of the Pacific Ocean,however,aseismic ridges and oceanic plateaus are subducted at relatively high angles(>30°).These subduction processes can generate large scale eruptions of basalts,basaltic andesites and andesites,which may be derived from fractional crystallization of magmas originating from the subduction zone fluid-metasomatized mantle wedge.In addition,some inactive arc ridges are subducted beneath Southwest Japan,and these subduction processes are commonly associated with the production of basalts,high-Mg andesites and adakites and Au mineralization.Besides magmatism and Cu-Au mineralization,ridge subduction may also trigger subduction erosion in subduction zones.Future frontiers of research will include characterizing the spatial and temporal patterns of ridge subduction events,clarifying the associated geodynamic mechanisms,quantifying subduction zone material recycling,establishing the associated deep crustal and mantle events that generate or influence magmatism and Cu-Au mineralization,establishing criteria to recognize pre-Cenozoic ridge subduction,the onset of modernstyle plate tectonics and the growth mechanisms for Archean continental crust.
