Located on the east boundary of Qinghai-Xizang （Tibet） Plateau, the Ms8.0 Wenchnan earthquake is the strongest event to hit the active block since the 2001 Kunlun Mountains Pass earthquake. In this study, a simplifi...Located on the east boundary of Qinghai-Xizang （Tibet） Plateau, the Ms8.0 Wenchnan earthquake is the strongest event to hit the active block since the 2001 Kunlun Mountains Pass earthquake. In this study, a simplified source model of the Wenchnan earthquake is constructed based on the deep/shallow tectonic settings and crust/mantle structure features of the Longmenshan thrust fault zone. On the basis of dynamic model abstraction, we construct a system of dynamical equations for the seismogenic process and obtain the analytical expressions of stress and strain in the seismogenic process. A preliminary study of the seismogenic process of the Ms8.0 Wenchuan earthquake, based on the analytical solution of the model and observation of tectonic deformation in the Longmenshan region, indicates that the seismogenic process of the Wenchuan earthquake took place over a period of more than 3200 years. The slow process of seismogeny and the long recurrence period of strong earthquakes are attributed to the low deformation rate of the Longmenshan tectonic zone.展开更多
Water(or H) in the silicate mantle is a key element in influencing Earth's climate, habitability, geochemical evolution, geophysical properties and geodynamical processes, and has received increasing attention in ...Water(or H) in the silicate mantle is a key element in influencing Earth's climate, habitability, geochemical evolution, geophysical properties and geodynamical processes, and has received increasing attention in the past decades. Experimental work under simulated high-pressure and high-temperature conditions is a powerful tool in characterizing the species, distribution, storage capacity and various physicochemical impacts of water in the mantle. In recent years, significant approaches have been acquired about some key physical, chemical and dynamical properties of water in the mantle and their various impacts, as a result of extensive studies by high-pressure and temperature experiments, and our knowledge of Earth's water cycle, especially the deep water cycle, on both temporal and spatial scales has been greatly enhanced. In this paper, a brief review based mainly on experimental studies is presented concerning the current understanding and some recent approaches of water in the silicate mantle, such as the possible origin, amount, storage and the effect on mantle properties.展开更多
With unique physical and chemical properties, aqueous solutions in the mantle may play important roles for a number of geochemical and geodynamical processes. However, since experimental data available are very limite...With unique physical and chemical properties, aqueous solutions in the mantle may play important roles for a number of geochemical and geodynamical processes. However, since experimental data available are very limited, people still know little about the aqueous solutions and their interactions with surrounding rocks and melts. From the perspective of thermodynamics, equation of state(EOS) is the key to push forward the modeling of aqueous solutions. Nevertheless, up to now accurate EOSs suitable for the mantle conditions are still in shortage. With discussions over several recognized EOSs, we summarize several ways to enhance the predictability of EOS: utilizing high quality data from molecular simulations, choosing functions with sound physical background, and improving the regression procedures for the empirical parameters. In the meantime, we find that the ion-bearing systems are still the focus of challenges in this area. New developments of experiments and computer simulations effectively deal with these challenges and in-depth understandings of aqueous solutions in the mantle are expected in the near future.展开更多
Tarim Large Igneous Province （TLIP） is the second Late Paleozoic LIPs in China after the recognition of Emeishan LIP, and is a hot research topic in geosciences. On the basis of the analysis of research history abou...Tarim Large Igneous Province （TLIP） is the second Late Paleozoic LIPs in China after the recognition of Emeishan LIP, and is a hot research topic in geosciences. On the basis of the analysis of research history about TLIP, this paper summarizes the re- search result during last twenty years and suggests the key research area in the future. The residual distribution range of TLIP is up to 250000 km2, and the largest residual thickness is 780 m. The eruption of basalt happened during 290-288 Ma and be- longs to LIPs magmatic event with fast eruption of magma. The lithological units of the TLIP include basalt, diabase, layered intrusive rock, breccia pipe mica-olivine pyroxenite, olivine pyroxenite, gabbro, ultramafic dyke, quartz syenite, quartz syenite porphyry and bimodal dyke. The basalt and diabase of TLIP exhibit OIB-like trace element patterns and enrichment of LILE and HFSE, and mainly belong to high TiO2 series. There is an obvious difference in isotope among the basalt from Keping and the basalt and dibase from the northern Tarim Basin. The basalt from Keping with negative eNa and high REE value derives from enriched mantle, and the diabase and basalt from the northern Tarim Basin with positive ENa and low REE value axe re- lated to depleted mantle. The crust uplifting in the Early Permian and the development of picrite and large scale dyke and for- mation of large scale V-Ti-Magnetite deposit in Wajilitag area support the view that the TLIP is related to mantle plume. The TLIP has a temporal-spatial relationship with Permian basic to ultra-basic igneous rock, which is distributed widely in Central Asia, and they represent a tectono-magmatic event with very important geodynamic setting. This paper also suggests that the deep geological process, the relation with mantle plume, mineralization, the relation with environmental change and biological evolution, and the geodynamics of the TLIP will be the key research topics in the future.展开更多
基金sponsored by the Basic Science and Technology Research Special Program of the Institute of Earthquake Science ,CEA(02076902-11)
文摘Located on the east boundary of Qinghai-Xizang （Tibet） Plateau, the Ms8.0 Wenchnan earthquake is the strongest event to hit the active block since the 2001 Kunlun Mountains Pass earthquake. In this study, a simplified source model of the Wenchnan earthquake is constructed based on the deep/shallow tectonic settings and crust/mantle structure features of the Longmenshan thrust fault zone. On the basis of dynamic model abstraction, we construct a system of dynamical equations for the seismogenic process and obtain the analytical expressions of stress and strain in the seismogenic process. A preliminary study of the seismogenic process of the Ms8.0 Wenchuan earthquake, based on the analytical solution of the model and observation of tectonic deformation in the Longmenshan region, indicates that the seismogenic process of the Wenchuan earthquake took place over a period of more than 3200 years. The slow process of seismogeny and the long recurrence period of strong earthquakes are attributed to the low deformation rate of the Longmenshan tectonic zone.
基金supported by the National Basic Research Program of China(Grant Nos.2014CB845904 and 41590622)the National Natural Science Foundation of China(Grant No.41372041)+1 种基金the Recruitment Program of Global Young Experts(China)the Fundamental Research Funds for the Central Universities(China)
文摘Water(or H) in the silicate mantle is a key element in influencing Earth's climate, habitability, geochemical evolution, geophysical properties and geodynamical processes, and has received increasing attention in the past decades. Experimental work under simulated high-pressure and high-temperature conditions is a powerful tool in characterizing the species, distribution, storage capacity and various physicochemical impacts of water in the mantle. In recent years, significant approaches have been acquired about some key physical, chemical and dynamical properties of water in the mantle and their various impacts, as a result of extensive studies by high-pressure and temperature experiments, and our knowledge of Earth's water cycle, especially the deep water cycle, on both temporal and spatial scales has been greatly enhanced. In this paper, a brief review based mainly on experimental studies is presented concerning the current understanding and some recent approaches of water in the silicate mantle, such as the possible origin, amount, storage and the effect on mantle properties.
基金supported by the National Natural Science Foundation of China (Grant Nos. 41590620 & 41473060)
文摘With unique physical and chemical properties, aqueous solutions in the mantle may play important roles for a number of geochemical and geodynamical processes. However, since experimental data available are very limited, people still know little about the aqueous solutions and their interactions with surrounding rocks and melts. From the perspective of thermodynamics, equation of state(EOS) is the key to push forward the modeling of aqueous solutions. Nevertheless, up to now accurate EOSs suitable for the mantle conditions are still in shortage. With discussions over several recognized EOSs, we summarize several ways to enhance the predictability of EOS: utilizing high quality data from molecular simulations, choosing functions with sound physical background, and improving the regression procedures for the empirical parameters. In the meantime, we find that the ion-bearing systems are still the focus of challenges in this area. New developments of experiments and computer simulations effectively deal with these challenges and in-depth understandings of aqueous solutions in the mantle are expected in the near future.
基金supported by the National Natural Science Foundation of China(Grant No.40930315)National Basic Research Program of China(Grant Nos.2007CB411303&2011CB808902)
文摘Tarim Large Igneous Province （TLIP） is the second Late Paleozoic LIPs in China after the recognition of Emeishan LIP, and is a hot research topic in geosciences. On the basis of the analysis of research history about TLIP, this paper summarizes the re- search result during last twenty years and suggests the key research area in the future. The residual distribution range of TLIP is up to 250000 km2, and the largest residual thickness is 780 m. The eruption of basalt happened during 290-288 Ma and be- longs to LIPs magmatic event with fast eruption of magma. The lithological units of the TLIP include basalt, diabase, layered intrusive rock, breccia pipe mica-olivine pyroxenite, olivine pyroxenite, gabbro, ultramafic dyke, quartz syenite, quartz syenite porphyry and bimodal dyke. The basalt and diabase of TLIP exhibit OIB-like trace element patterns and enrichment of LILE and HFSE, and mainly belong to high TiO2 series. There is an obvious difference in isotope among the basalt from Keping and the basalt and dibase from the northern Tarim Basin. The basalt from Keping with negative eNa and high REE value derives from enriched mantle, and the diabase and basalt from the northern Tarim Basin with positive ENa and low REE value axe re- lated to depleted mantle. The crust uplifting in the Early Permian and the development of picrite and large scale dyke and for- mation of large scale V-Ti-Magnetite deposit in Wajilitag area support the view that the TLIP is related to mantle plume. The TLIP has a temporal-spatial relationship with Permian basic to ultra-basic igneous rock, which is distributed widely in Central Asia, and they represent a tectono-magmatic event with very important geodynamic setting. This paper also suggests that the deep geological process, the relation with mantle plume, mineralization, the relation with environmental change and biological evolution, and the geodynamics of the TLIP will be the key research topics in the future.
