Recent advances in three-dimensional numerical simulations of mantle convection have aided in approximately reproducing continental movement since the Pangea breakup at 200 Ma. These have also led to a better understa...Recent advances in three-dimensional numerical simulations of mantle convection have aided in approximately reproducing continental movement since the Pangea breakup at 200 Ma. These have also led to a better understanding of the thermal and mechanical coupling between mantle convection and surface plate motion and predictions of the configuration of the next supercontinent. The simulations of mantle convection from 200 Ma to the present reveals that the development of large-scale cold mantle downwellings in the North Tethys Ocean at the earlier stage of the Pangea breakup triggered the northward movement of the Indian subcontinent. The model of high temperature anomaly region beneath Pangea resulting from the thermal insulation effect support the breakup of Pangea in the real Earth time scale, as also suggested in previous geological and geodynamic models. However, considering the low radioactive heat generation rate of the depleted upper mantle, the high temperature anomaly region might have been generated by upwelling plumes with contribution of deep subducted TTG(tonalite-trondhjemite-granite) materials enriched in radiogenic elements. Integrating the numerical results of mantle convection from 200 Ma to the present, and from the present to the future, it is considered that the mantle drag force acting on the base of continents may be comparable to the slab pull force, which implies that convection in the shallower part of the mantle is strongly coupled with surface plate motion.展开更多
About three decades after the establishment of the plate tec- tonics theory in the late 1960s, Maruyama （1994） proposed the ＂plume tectonics＂ theory based on whole-mantle seismic tomogra- phy image （Fukao, 1992; ...About three decades after the establishment of the plate tec- tonics theory in the late 1960s, Maruyama （1994） proposed the ＂plume tectonics＂ theory based on whole-mantle seismic tomogra- phy image （Fukao, 1992; Fukao et al., 1994）. According to this the- ory, the earth＇s interior is divided into three regimes： the earth＇s surface region governed by lateral motions of tectonic plates, the mantle governed by vertical motions of ＂superplumes＂ （i.e., large- scale mantle upwelling/downwelling plumes）, and the core, whose convection style is probably controlled by superplumes in the mantle. With the rapid progress in earth science after the birth of the plume tectonics theory, it is now widely accepted that various geological phenomena observed in the earth＇s surface are closely linked to the fluid motion in the deep mantle （e.g., Davies, 2011）.展开更多
文摘Recent advances in three-dimensional numerical simulations of mantle convection have aided in approximately reproducing continental movement since the Pangea breakup at 200 Ma. These have also led to a better understanding of the thermal and mechanical coupling between mantle convection and surface plate motion and predictions of the configuration of the next supercontinent. The simulations of mantle convection from 200 Ma to the present reveals that the development of large-scale cold mantle downwellings in the North Tethys Ocean at the earlier stage of the Pangea breakup triggered the northward movement of the Indian subcontinent. The model of high temperature anomaly region beneath Pangea resulting from the thermal insulation effect support the breakup of Pangea in the real Earth time scale, as also suggested in previous geological and geodynamic models. However, considering the low radioactive heat generation rate of the depleted upper mantle, the high temperature anomaly region might have been generated by upwelling plumes with contribution of deep subducted TTG(tonalite-trondhjemite-granite) materials enriched in radiogenic elements. Integrating the numerical results of mantle convection from 200 Ma to the present, and from the present to the future, it is considered that the mantle drag force acting on the base of continents may be comparable to the slab pull force, which implies that convection in the shallower part of the mantle is strongly coupled with surface plate motion.
文摘About three decades after the establishment of the plate tec- tonics theory in the late 1960s, Maruyama （1994） proposed the ＂plume tectonics＂ theory based on whole-mantle seismic tomogra- phy image （Fukao, 1992; Fukao et al., 1994）. According to this the- ory, the earth＇s interior is divided into three regimes： the earth＇s surface region governed by lateral motions of tectonic plates, the mantle governed by vertical motions of ＂superplumes＂ （i.e., large- scale mantle upwelling/downwelling plumes）, and the core, whose convection style is probably controlled by superplumes in the mantle. With the rapid progress in earth science after the birth of the plume tectonics theory, it is now widely accepted that various geological phenomena observed in the earth＇s surface are closely linked to the fluid motion in the deep mantle （e.g., Davies, 2011）.
