Since 1982, the Institute of Oceanology, Chinese Academy of Sciences(IOCAS) has conducted more than 20 sonobuoy refraction measurement in the area of East China Sea. In 1991, the IOCAS also conducted OBS measurement i...Since 1982, the Institute of Oceanology, Chinese Academy of Sciences(IOCAS) has conducted more than 20 sonobuoy refraction measurement in the area of East China Sea. In 1991, the IOCAS also conducted OBS measurement in the same area. Both the our refraction data and other authors’ refraction data measured in the area of East China Sea have been used to study the crustal velocity structure along the Profile 820 which is across the East China Sea shelf basin, Okinawa Trough, Ryukyu Island, Ryukyu Trench and Philippine Sea in this paper. The ages of the velocity layer have also been determined in this paper.The crustal velocity structure is difference both along the profile 820 and from top to the depth. Along the profile there are three basins and three uplifts. From top to the depth there are 5 velocity layers, which are layers of 1 8～2 2km/s, 2 4～2 8km/s, 3 0～3 6km/s, 4 2～5 1km/s, 5 75～6 0km/s. Based on the velocity structure we can know that the deposit environment was stable between Pliocene and Quaternary along the whole profile except the axis part of Okinawa Trough which had always been active and the deposit florescence was Eocene and the whole area was uplifting in the time of Oligocene and the sediments of that time upon the Diaoyudao uplift and Ryukyu island and also the area of East China Sea shelf basin and Okinawa Trough were denuded. The origination of the East China Sea shelf basin and the Okinawa Trough might be after the deposition of the velocity layer of 5 75～6 0km/s.展开更多
The Nampula Subprovince in Northern Mozambique is a Mesoproterozoic gneiss terrane with a Pan-African(523-550 Ma)amphibolite-facies met- amorphic overprint.The province forms a pivotal part of the evolution and final ...The Nampula Subprovince in Northern Mozambique is a Mesoproterozoic gneiss terrane with a Pan-African(523-550 Ma)amphibolite-facies met- amorphic overprint.The province forms a pivotal part of the evolution and final assembly of Gondwana on the eastern seaboard of the African continent.展开更多
为系统、深入地研究中国西部盆(盆地)、山(山脉)、原(高原)的壳幔结构与深部动力学过程,2003年我们提出并领导实施了“羚羊计划”(ANTILOPE-Array Network of Tibetan International Lithospheric Observation and Probe Experiments),...为系统、深入地研究中国西部盆(盆地)、山(山脉)、原(高原)的壳幔结构与深部动力学过程,2003年我们提出并领导实施了“羚羊计划”(ANTILOPE-Array Network of Tibetan International Lithospheric Observation and Probe Experiments),在青藏高原先后完成了羚羊-I(ANTILOPE-I)到羚羊-IV(ANTILOPE-IV)4条二维宽频带台阵剖面,而在青藏高原东西构造结则实施了羚羊-V和羚羊-VI两个三维宽频带台阵探测。另外,我们将前期在准噶尔盆地、天山造山带、塔里木盆地、阿尔金造山带和柴达木盆地开展的九条综合地球物理观测剖面也纳入羚羊计划的总体框架中来。通过“羚羊计划”的实施,我们在中国西部(包括西北部的环青藏高原盆山体系以及西南部的青藏高原)取得了大量的、高质量的、综合的第一手观测数据,获得了中国西部盆、山、原精细的壳幔结构,系统地揭示了中国西部盆山原的深部地球动力学过程。主要结论总结如下:确定了准噶尔盆地基底的结构与属性,优化了盆地的基底构造格架;建立了天山造山带“层间插入削减”新的陆内造山模式,揭示了印欧碰撞在天山岩石圈缩短44%的去向以及由洋陆俯冲到陆陆碰撞俯冲的转换机制;揭示了塔里木盆地、阿尔金造山带和柴达木盆地的盆山接触关系;获得了塔里木盆地顺时针旋转的深部几何学、运动学和动力学证据;确定了青藏高原之下印度板块与欧亚板块的碰撞边界;发现目前的青藏高原由南部的印度板块、北部的欧亚板块和夹持于二者之间的巨型破碎区——西藏“板块”构成,首次确定了各自的岩石圈底边界;修正了高原变形的两个端员模型;建立了深部构造对地表地形的制约关系;系统地揭示了印度板块沿喜马拉雅造山带俯冲的水平距离与俯冲角度的变化规律与控制因素。“羚羊计划”以其巨大的观测网络与综合地球物理探测技术,采用展开更多
The quantitative analysis of uplift process of the Qinghai—Tibet plateau is a key to deepen the study of uplift mechanism and dynamic model, for this, numerical simulate was done to the whole process of uplift of the...The quantitative analysis of uplift process of the Qinghai—Tibet plateau is a key to deepen the study of uplift mechanism and dynamic model, for this, numerical simulate was done to the whole process of uplift of the Qinghai—Tibet plateau.1 Geological model According to the tectonic evolution and lithospheric structure, continental crust in the Qinghai—Tibet plateau in profile is divided into sedimentary cover, crystalline rock formation and lower crust and composed of Kunlun, Bayan Har, Qiangtang, Gangdise and Himalaya blocks on the plane. Layer or block is bounded the detachment layer or large fault. On the basis of the uplift characteristics, the calculated time limit is in the Cenozoic since 65Ma, roughly four stages, i.e., 65 to 40Ma, 40 to 20Ma, 20 to 3Ma and 3Ma to now. Mesh profile used Yadong—Golmud Geoscience transect.展开更多
Landslide is one of the common natural hazards occurring in Sri Lanka.This is more signifycant in central highlands of the country.Some natural conditions of central highlands like geology and geomorphological feature...Landslide is one of the common natural hazards occurring in Sri Lanka.This is more signifycant in central highlands of the country.Some natural conditions of central highlands like geology and geomorphological features,steep slopes,getting high intensity of rainfall,etc.are direct influences on occurrence of high number of landslides compared to other regions of Sri Lanka.However,some human activities like deforestation,chena cultivation,improper constructions in hill slopes,etc.also contribute to accelerating landslide process in the study area. According to statistic data of past landslides of this region,those events destroyed valuable agricultural lands,houses and properties,etc.as well as lost展开更多
The Cretaceous Ambohiby Complex is an alkaline ring complex located in the west central part of Madagascar and covers a mountainous area of approximate 225 km^2.The complex intrudes into Precambrian basement gneisses ...The Cretaceous Ambohiby Complex is an alkaline ring complex located in the west central part of Madagascar and covers a mountainous area of approximate 225 km^2.The complex intrudes into Precambrian basement gneisses and is dominated by alkaline mafic to felsic rocks with sodic mineralogies. Pyroxenes are generally aegirine,aegirine-augite,and hedenbergite and commonly occur in granites,展开更多
文摘Since 1982, the Institute of Oceanology, Chinese Academy of Sciences(IOCAS) has conducted more than 20 sonobuoy refraction measurement in the area of East China Sea. In 1991, the IOCAS also conducted OBS measurement in the same area. Both the our refraction data and other authors’ refraction data measured in the area of East China Sea have been used to study the crustal velocity structure along the Profile 820 which is across the East China Sea shelf basin, Okinawa Trough, Ryukyu Island, Ryukyu Trench and Philippine Sea in this paper. The ages of the velocity layer have also been determined in this paper.The crustal velocity structure is difference both along the profile 820 and from top to the depth. Along the profile there are three basins and three uplifts. From top to the depth there are 5 velocity layers, which are layers of 1 8～2 2km/s, 2 4～2 8km/s, 3 0～3 6km/s, 4 2～5 1km/s, 5 75～6 0km/s. Based on the velocity structure we can know that the deposit environment was stable between Pliocene and Quaternary along the whole profile except the axis part of Okinawa Trough which had always been active and the deposit florescence was Eocene and the whole area was uplifting in the time of Oligocene and the sediments of that time upon the Diaoyudao uplift and Ryukyu island and also the area of East China Sea shelf basin and Okinawa Trough were denuded. The origination of the East China Sea shelf basin and the Okinawa Trough might be after the deposition of the velocity layer of 5 75～6 0km/s.
文摘The Nampula Subprovince in Northern Mozambique is a Mesoproterozoic gneiss terrane with a Pan-African(523-550 Ma)amphibolite-facies met- amorphic overprint.The province forms a pivotal part of the evolution and final assembly of Gondwana on the eastern seaboard of the African continent.
文摘为系统、深入地研究中国西部盆(盆地)、山(山脉)、原(高原)的壳幔结构与深部动力学过程,2003年我们提出并领导实施了“羚羊计划”(ANTILOPE-Array Network of Tibetan International Lithospheric Observation and Probe Experiments),在青藏高原先后完成了羚羊-I(ANTILOPE-I)到羚羊-IV(ANTILOPE-IV)4条二维宽频带台阵剖面,而在青藏高原东西构造结则实施了羚羊-V和羚羊-VI两个三维宽频带台阵探测。另外,我们将前期在准噶尔盆地、天山造山带、塔里木盆地、阿尔金造山带和柴达木盆地开展的九条综合地球物理观测剖面也纳入羚羊计划的总体框架中来。通过“羚羊计划”的实施,我们在中国西部(包括西北部的环青藏高原盆山体系以及西南部的青藏高原)取得了大量的、高质量的、综合的第一手观测数据,获得了中国西部盆、山、原精细的壳幔结构,系统地揭示了中国西部盆山原的深部地球动力学过程。主要结论总结如下:确定了准噶尔盆地基底的结构与属性,优化了盆地的基底构造格架;建立了天山造山带“层间插入削减”新的陆内造山模式,揭示了印欧碰撞在天山岩石圈缩短44%的去向以及由洋陆俯冲到陆陆碰撞俯冲的转换机制;揭示了塔里木盆地、阿尔金造山带和柴达木盆地的盆山接触关系;获得了塔里木盆地顺时针旋转的深部几何学、运动学和动力学证据;确定了青藏高原之下印度板块与欧亚板块的碰撞边界;发现目前的青藏高原由南部的印度板块、北部的欧亚板块和夹持于二者之间的巨型破碎区——西藏“板块”构成,首次确定了各自的岩石圈底边界;修正了高原变形的两个端员模型;建立了深部构造对地表地形的制约关系;系统地揭示了印度板块沿喜马拉雅造山带俯冲的水平距离与俯冲角度的变化规律与控制因素。“羚羊计划”以其巨大的观测网络与综合地球物理探测技术,采用
文摘The quantitative analysis of uplift process of the Qinghai—Tibet plateau is a key to deepen the study of uplift mechanism and dynamic model, for this, numerical simulate was done to the whole process of uplift of the Qinghai—Tibet plateau.1 Geological model According to the tectonic evolution and lithospheric structure, continental crust in the Qinghai—Tibet plateau in profile is divided into sedimentary cover, crystalline rock formation and lower crust and composed of Kunlun, Bayan Har, Qiangtang, Gangdise and Himalaya blocks on the plane. Layer or block is bounded the detachment layer or large fault. On the basis of the uplift characteristics, the calculated time limit is in the Cenozoic since 65Ma, roughly four stages, i.e., 65 to 40Ma, 40 to 20Ma, 20 to 3Ma and 3Ma to now. Mesh profile used Yadong—Golmud Geoscience transect.
文摘Landslide is one of the common natural hazards occurring in Sri Lanka.This is more signifycant in central highlands of the country.Some natural conditions of central highlands like geology and geomorphological features,steep slopes,getting high intensity of rainfall,etc.are direct influences on occurrence of high number of landslides compared to other regions of Sri Lanka.However,some human activities like deforestation,chena cultivation,improper constructions in hill slopes,etc.also contribute to accelerating landslide process in the study area. According to statistic data of past landslides of this region,those events destroyed valuable agricultural lands,houses and properties,etc.as well as lost
文摘The Cretaceous Ambohiby Complex is an alkaline ring complex located in the west central part of Madagascar and covers a mountainous area of approximate 225 km^2.The complex intrudes into Precambrian basement gneisses and is dominated by alkaline mafic to felsic rocks with sodic mineralogies. Pyroxenes are generally aegirine,aegirine-augite,and hedenbergite and commonly occur in granites,
