Plate motion representing a remarkable Earth process is widely attributed to several primary forces such as ridge push and slab pull. Recently, we have presented that the ocean water pressure against the wall of conti...Plate motion representing a remarkable Earth process is widely attributed to several primary forces such as ridge push and slab pull. Recently, we have presented that the ocean water pressure against the wall of continents may generate enormous force on continents. Continents are physically fixed on the top of the lithosphere that has been already broken into individual plates, this attachment enables the force to be laterally transferred to the lithospheric plates. In this study, we combine the force and the existing plate driving forces (i.e., ridge push, slab pull, collisional, and shearing) to account for plate motion. We show that the modelled movements for the South American, African, North American, Eurasian, Australian, Pacific plates are well agreement with the observed movements in both speed and azimuth, with a Root Mean Square Error (RMSE) of the modelled speed against the observed speed of 0.91, 3.76, 2.77, 2.31, 7.43, and 1.95 mm/yr, respectively.展开更多
Songliao Basin,the largest Mesozoic intracontinental nonmarine basin in eastern China,initiated during the latest Jurassic as a backarc extensional basin;rifting failed and thermal cooling controlled subsidence throug...Songliao Basin,the largest Mesozoic intracontinental nonmarine basin in eastern China,initiated during the latest Jurassic as a backarc extensional basin;rifting failed and thermal cooling controlled subsidence through the early Late Cretaceous.Integrating 2-D and 3D reflection seismic and borehole data with regional geological studies,we interpret sedimentary sequence and structural patterns of the Coniacian-Maastrichtian fill of Songliao Basin as defining a retroforeland basin system developed after 88 Ma(marked by the T11 unconformity in the basin),including(1)significant increase in the thickness of the Nenjiang Formation eastward towards orogenic highlands of the Zhangguangcai Range and the convergent continental margin;(2)a shift of detrital provenance in the basin from north to southeast;and(3)propagation of E-W shortened structures,increasing eastward in amplitude,frequency,and degree of inversion toward the orogen.During latest Cretaceous,foreland basin fill progressively deformed,as the foredeep evolved to a wedge-top tectonic setting,marked by the basin-wide T04 unconformity within the upper Nenjiang Formation at 81.6 Ma.Much of the basin was brought into the orogenic wedge and eroded by the end of the Cretaceous.Late Jurassic/Early Cretaceous backarc rifting of uncratonized basement comprised of accreted terranes likely facilitated and localized the foreland.Synrift normal faults reactivated and extensively inverted as thrust faults are prominent in the eastern 1/3 of the basin,whereas folds developed above detachments in shaley early post-rift strata dominate the western 2/3 of the basin.Songliao foreland development likely was driven by changing plate dynamics and collision along the Pacific margin after 88 Ma.展开更多
The Itmurundy Zone of Central Kazakhstan is a key structure in the core of the Kazakh Orocline representing a typical Pacific-type orogenic belt hosting accretionary complex,ophiolite massifs and serpentinite mél...The Itmurundy Zone of Central Kazakhstan is a key structure in the core of the Kazakh Orocline representing a typical Pacific-type orogenic belt hosting accretionary complex,ophiolite massifs and serpentinite mélange.The main controversies in the existing tectonic models of the Itmurundy Zone are about the timing of subduction and accretion,the direction and kinematics of subduction and the number of oceanic plates.A new model for the early Paleozoic tectonic story of the Itmurundy Zone is postulated in this paper,based on new detailed geological and U-Pb detrital zircon age data,combined with previously documented geological,U-Pb age,microfossil,geochemical and isotope data from igneous rocks,deep-sea sediments and greywacke sandstones.The present study employs the Ocean Plate Stratigraphy(OPS)model to explain the tectonic processes involved in the evolution of the Itmurundy Zone and to pre-sent a holistic story of Ordovician oceanic plate(s),which accretion formed an accretionary complex.The detailed mapping allows distinguishing three types of OPS assemblages:(1)Chert-dominated,(2)OIB-hosting,and(3)MORB-hosting.The U-Pb ages of detrital zircons from sandstones of OIB and Chert types show unimodal distributions with similar main peaks of magmatism at 460-455 Ma in the provenance,and their maximum depositional ages(MDA)span 455-433 Ma.Two samples from OPS Type 3 show the peaks of magmatism both at ca.460 Ma and the MDA of 452 Ma and 459 Ma,respectively.The MDA of sandstones and microfossils data from chert show the younging of strata to the south and SE in Types 1 and 2 and to NEE for Type 3(in present coordinates)suggesting double-sided subduction to the NNW and SEE and,accordingly,the co-existence of pieces of two oceanic plates in Ordovician time.The U-Pb zircon data from both igneous and clastic rocks indicate a period of subduction erosion in early Ordovician time.As a whole,the accreted OPS units of the Itmurundy Zone record the timing of subduction and accretion from the early Ordovician to the early Silurian,i.e.,60 Ma at shortest.展开更多
文摘Plate motion representing a remarkable Earth process is widely attributed to several primary forces such as ridge push and slab pull. Recently, we have presented that the ocean water pressure against the wall of continents may generate enormous force on continents. Continents are physically fixed on the top of the lithosphere that has been already broken into individual plates, this attachment enables the force to be laterally transferred to the lithospheric plates. In this study, we combine the force and the existing plate driving forces (i.e., ridge push, slab pull, collisional, and shearing) to account for plate motion. We show that the modelled movements for the South American, African, North American, Eurasian, Australian, Pacific plates are well agreement with the observed movements in both speed and azimuth, with a Root Mean Square Error (RMSE) of the modelled speed against the observed speed of 0.91, 3.76, 2.77, 2.31, 7.43, and 1.95 mm/yr, respectively.
基金support from the Innovative Research Group Project of the National Natural Science Foundation of China,Award Number 41790450.
文摘Songliao Basin,the largest Mesozoic intracontinental nonmarine basin in eastern China,initiated during the latest Jurassic as a backarc extensional basin;rifting failed and thermal cooling controlled subsidence through the early Late Cretaceous.Integrating 2-D and 3D reflection seismic and borehole data with regional geological studies,we interpret sedimentary sequence and structural patterns of the Coniacian-Maastrichtian fill of Songliao Basin as defining a retroforeland basin system developed after 88 Ma(marked by the T11 unconformity in the basin),including(1)significant increase in the thickness of the Nenjiang Formation eastward towards orogenic highlands of the Zhangguangcai Range and the convergent continental margin;(2)a shift of detrital provenance in the basin from north to southeast;and(3)propagation of E-W shortened structures,increasing eastward in amplitude,frequency,and degree of inversion toward the orogen.During latest Cretaceous,foreland basin fill progressively deformed,as the foredeep evolved to a wedge-top tectonic setting,marked by the basin-wide T04 unconformity within the upper Nenjiang Formation at 81.6 Ma.Much of the basin was brought into the orogenic wedge and eroded by the end of the Cretaceous.Late Jurassic/Early Cretaceous backarc rifting of uncratonized basement comprised of accreted terranes likely facilitated and localized the foreland.Synrift normal faults reactivated and extensively inverted as thrust faults are prominent in the eastern 1/3 of the basin,whereas folds developed above detachments in shaley early post-rift strata dominate the western 2/3 of the basin.Songliao foreland development likely was driven by changing plate dynamics and collision along the Pacific margin after 88 Ma.
基金supported by the Russian Science Foundation(#21-77-20022,stratigraphy,geochronology,geochemistry)Fundamental Research Funds for the Central Universities of China(2682023CX016,paper preparation)Ministry of Science and Higher Education of Russia,State Assignment Projects(122041400044-2 and FSUS-2020-0039)(petrography,isotopes,geodynamic implications).
文摘The Itmurundy Zone of Central Kazakhstan is a key structure in the core of the Kazakh Orocline representing a typical Pacific-type orogenic belt hosting accretionary complex,ophiolite massifs and serpentinite mélange.The main controversies in the existing tectonic models of the Itmurundy Zone are about the timing of subduction and accretion,the direction and kinematics of subduction and the number of oceanic plates.A new model for the early Paleozoic tectonic story of the Itmurundy Zone is postulated in this paper,based on new detailed geological and U-Pb detrital zircon age data,combined with previously documented geological,U-Pb age,microfossil,geochemical and isotope data from igneous rocks,deep-sea sediments and greywacke sandstones.The present study employs the Ocean Plate Stratigraphy(OPS)model to explain the tectonic processes involved in the evolution of the Itmurundy Zone and to pre-sent a holistic story of Ordovician oceanic plate(s),which accretion formed an accretionary complex.The detailed mapping allows distinguishing three types of OPS assemblages:(1)Chert-dominated,(2)OIB-hosting,and(3)MORB-hosting.The U-Pb ages of detrital zircons from sandstones of OIB and Chert types show unimodal distributions with similar main peaks of magmatism at 460-455 Ma in the provenance,and their maximum depositional ages(MDA)span 455-433 Ma.Two samples from OPS Type 3 show the peaks of magmatism both at ca.460 Ma and the MDA of 452 Ma and 459 Ma,respectively.The MDA of sandstones and microfossils data from chert show the younging of strata to the south and SE in Types 1 and 2 and to NEE for Type 3(in present coordinates)suggesting double-sided subduction to the NNW and SEE and,accordingly,the co-existence of pieces of two oceanic plates in Ordovician time.The U-Pb zircon data from both igneous and clastic rocks indicate a period of subduction erosion in early Ordovician time.As a whole,the accreted OPS units of the Itmurundy Zone record the timing of subduction and accretion from the early Ordovician to the early Silurian,i.e.,60 Ma at shortest.
