The roles of subduction of the Pacific plate and the big mantle wedge(BMW) in the evolution of east Asian continental margin have attracted lots of attention in past years. This paper reviews recent progresses regardi...The roles of subduction of the Pacific plate and the big mantle wedge(BMW) in the evolution of east Asian continental margin have attracted lots of attention in past years. This paper reviews recent progresses regarding the composition and chemical heterogeneity of the BMW beneath eastern Asia and geochemistry of Cenozoic basalts in the region, with attempts to put forward a general model accounting for the generation of intraplate magma in a BMW system. Some key points of this review are summarized in the following.(1) Cenozoic basalts from eastern China are interpreted as a mixture of high-Si melts and low-Si melts. Wherever they are from, northeast, north or south China, Cenozoic basalts share a common low-Si basalt endmember, which is characterized by high alkali, Fe_2O_3~T and TiO_2 contents, HIMU-like trace element composition and relatively low ^(206)Pb/^(204)Pb compared to classic HIMU basalts. Their Nd-Hf isotopic compositions resemble that of Pacific Mantle domain and their source is composed of carbonated eclogites and peridotites. The high-Si basalt endmember is characterized by low alkali, Fe_2O_3~T and TiO_2 contents, Indian Mantle-type Pb-Nd-Hf isotopic compositions, and a predominant garnet pyroxenitic source. High-Si basalts show isotopic provinciality, with those from North China and South China displaying EM1-type and EM2-type components, respectively, while basalts from Northeast China containing both EM1-and EM2-type components.(2) The source of Cenozoic basalts from eastern China contains abundant recycled materials, including oceanic crust and lithospheric mantle components as well as carbonate sediments and water. According to their spatial distribution and deep seismic tomography, it is inferred that the recycled components are mostly from stagnant slabs in the mantle transition zone,whereas EM1 and EM2 components are from the shallow mantle.(3) Comparison of solidi of garnet pyroxenite, carbonated eclogite and peridotite with regional geotherm constrains the initial melting depth of high展开更多
重新定义宝马未来BMW新世代概念车首秀中国。这并非宝马第一次使用“新世代”名称,1962年诞生的BMW 1500及其后续车型被统称为“Die NEUE KLASSE”(德语,中文“新世代”),这是宝马由内而外首次突破传统,开创全新细分市场。如今,BMW新世...重新定义宝马未来BMW新世代概念车首秀中国。这并非宝马第一次使用“新世代”名称,1962年诞生的BMW 1500及其后续车型被统称为“Die NEUE KLASSE”(德语,中文“新世代”),这是宝马由内而外首次突破传统,开创全新细分市场。如今,BMW新世代概念车再次演绎BMW轿车的未来,其全新BMW设计风格和“全景视域桥”等数字化交互创新,颠覆延续百年的汽车设计与交互功能,创造全新多感官智能体验,勾勒宝马对设计、数字化、驾驶乐趣的全面构想。展开更多
BMW X2,近日,BMWX家族中最年轻的运动型多功能轿跑车一全新BMWX2迎来中国上市,建议零售价为人民币31.69万元~41.99万元。其中,全新BMWX2sDrive25iM运动套装、全新BMWX2xDrive25iM运动曜夜套装车型已开始交付而BMWX2家族首次引入的M性能...BMW X2,近日,BMWX家族中最年轻的运动型多功能轿跑车一全新BMWX2迎来中国上市,建议零售价为人民币31.69万元~41.99万元。其中,全新BMWX2sDrive25iM运动套装、全新BMWX2xDrive25iM运动曜夜套装车型已开始交付而BMWX2家族首次引入的M性能车型一全新BMW X2M35i将于第二季度开始交付。展开更多
基金supported by the Chinese Academy of Sciences(Grant No.XDB18000000)the National Natural Science Foundation of China(Grant No.41688103)the State Oceanography Bureau(Grant No.GASI-GEOGE-02)
文摘The roles of subduction of the Pacific plate and the big mantle wedge(BMW) in the evolution of east Asian continental margin have attracted lots of attention in past years. This paper reviews recent progresses regarding the composition and chemical heterogeneity of the BMW beneath eastern Asia and geochemistry of Cenozoic basalts in the region, with attempts to put forward a general model accounting for the generation of intraplate magma in a BMW system. Some key points of this review are summarized in the following.(1) Cenozoic basalts from eastern China are interpreted as a mixture of high-Si melts and low-Si melts. Wherever they are from, northeast, north or south China, Cenozoic basalts share a common low-Si basalt endmember, which is characterized by high alkali, Fe_2O_3~T and TiO_2 contents, HIMU-like trace element composition and relatively low ^(206)Pb/^(204)Pb compared to classic HIMU basalts. Their Nd-Hf isotopic compositions resemble that of Pacific Mantle domain and their source is composed of carbonated eclogites and peridotites. The high-Si basalt endmember is characterized by low alkali, Fe_2O_3~T and TiO_2 contents, Indian Mantle-type Pb-Nd-Hf isotopic compositions, and a predominant garnet pyroxenitic source. High-Si basalts show isotopic provinciality, with those from North China and South China displaying EM1-type and EM2-type components, respectively, while basalts from Northeast China containing both EM1-and EM2-type components.(2) The source of Cenozoic basalts from eastern China contains abundant recycled materials, including oceanic crust and lithospheric mantle components as well as carbonate sediments and water. According to their spatial distribution and deep seismic tomography, it is inferred that the recycled components are mostly from stagnant slabs in the mantle transition zone,whereas EM1 and EM2 components are from the shallow mantle.(3) Comparison of solidi of garnet pyroxenite, carbonated eclogite and peridotite with regional geotherm constrains the initial melting depth of high
文摘重新定义宝马未来BMW新世代概念车首秀中国。这并非宝马第一次使用“新世代”名称,1962年诞生的BMW 1500及其后续车型被统称为“Die NEUE KLASSE”(德语,中文“新世代”),这是宝马由内而外首次突破传统,开创全新细分市场。如今,BMW新世代概念车再次演绎BMW轿车的未来,其全新BMW设计风格和“全景视域桥”等数字化交互创新,颠覆延续百年的汽车设计与交互功能,创造全新多感官智能体验,勾勒宝马对设计、数字化、驾驶乐趣的全面构想。
