中国及其邻区地球三维结构初始模型的建立
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摘要
对人工地震测深及天然地震面波体波三维层折反演数据进行统一处理，建立了中国及其邻区地球三维结构初始模型．此模型图像表明，中国及其邻区地球各圈层横向变化明显．岩石圈及软流圈内速度分布主要反映这一区域自古生代以来板块及地块拼合模式．各主要板块或地块（塔里木、扬子、中朝、青藏、哈萨克斯坦、印度、印度支那）岩石圈增厚或有很深的地慢根，板块或地块间的造山带岩石圈减薄，软流圈速度降低。下地幔底部及核幔边界D″层出现高速异常，表明古太平洋及古特提斯洋俯冲板块因重力坍塌已进入地球深层，形成亚洲超级下降地幔柱。这一下降地幔柱引起地球表层物质向中亚、东亚地区集中，印度半岛、青藏高原、新疆、蒙古至贝加尔一带，成为全球岩石圈最大的汇聚场所．
The continent of China and its adjacent regions formed by a series of plates and blocks convergence rapidly in the late Paleozoic (about 200-300 Ma). The Indian subcontinent collided with Eurasian continent causing the crust shorted and uplifted in the late Mesozoic to Paleocene epoch forming the highest plateau of Qinghai-Tibet and Pamir, and orogens of Himalayan and Hindu Kush. Based on the Global Creosciences Transects(GGT) and the results of tomographic inversion by seismic body wave and surface wave data, the three dimensional velocity structure from upper crust to Core-Mantle Boundary (CMB) have been reconstructed in China and its adjacent regions. It shows the great lateral various for each spherical layers in lithosphere /asthenosphere system (depth from 0 to about 400 km).Alpine-Himalayan belt throughout the Northern Pakistan (Hindu Kush and Pamir), Qinghai-Tibet plateau including Tarim basin and Tian-Shan mountain chain characterized by the continent-continent collision zone with thick crust and lithosphere.The eastern part is influenced by the motion of Pacific plate and with the thin crust and lithosphere. The average thickness of lithosphere in the region is about 100 km,several paleonuclei and paleolands, such as Tarim, Yangtze, Ordos and Indian shield are represented by great thickness of lithosphere. T'he fold belts, such as Altai, Qinlin belt, North-South tectonic belt, southeast continental margin, South China sea, East China sea. Ryukyu trench represented by thin lithosphere.In the lower mantle (depth in 700-1200 km) the velocity distribution shows the northsouth trend. The high velocity regions are presented in the Japan sea and East China sea, and also appear in the N-S tectonic belt through out central China. In the depth 2200-2800 km close the CMB region a huge high velocity anomaly is distributed from east to west, this could be explained as a super cold downwelling plume in the east and central Asia.The super downwelling plume underneath Asia is the dominant pattern of vertical mantle flow in the modem Earth. This huge cold plume is formed by the multi-subduction of oceanic plates of paleo Tethys and Pacific, the cold slabs was supplied by plates at trench and down to lower part of upper mantle (670 km in depth), where they were accumulated, and after a geologically significant time the stagnant mass of cold slabs gravitationally collapsed onto the CMB. Once it is formed in lower mantle, the mantle convection patterns in the upper mantle tends to be strongly controlled by a sole downwelling superplume in the lower mantle. Thus all continents tend to be swallowed into the cold superplume until they are collision and amalgamation to form a super-continent.The central Asia, from Indian subcontinent to Tibet, Xijiang, Mongolia and Baikal regions are the present largest convergence place in the world. there are thicken crust and lithosphere, showing high compressional stress in the crust, low heat flow and broad distributed earthquakes, and negative gravity anomaly, lowest geoid,all of these characteristics indicate the mantle materials fall down to the CMB and continents converged in this region.
The continent of China and its adjacent regions formed by a series of plates and blocks convergence rapidly in the late Paleozoic (about 200-300 Ma). The Indian subcontinent collided with Eurasian continent causing the crust shorted and uplifted in the late Mesozoic to Paleocene epoch forming the highest plateau of Qinghai-Tibet and Pamir, and orogens of Himalayan and Hindu Kush. Based on the Global Creosciences Transects(GGT) and the results of tomographic inversion by seismic body wave and surface wave data, the three dimensional velocity structure from upper crust to Core-Mantle Boundary (CMB) have been reconstructed in China and its adjacent regions. It shows the great lateral various for each spherical layers in lithosphere /asthenosphere system (depth from 0 to about 400 km).Alpine-Himalayan belt throughout the Northern Pakistan (Hindu Kush and Pamir), Qinghai-Tibet plateau including Tarim basin and Tian-Shan mountain chain characterized by the continent-continent collision zone with thick crust and lithosphere.The eastern part is influenced by the motion of Pacific plate and with the thin crust and lithosphere. The average thickness of lithosphere in the region is about 100 km,several paleonuclei and paleolands, such as Tarim, Yangtze, Ordos and Indian shield are represented by great thickness of lithosphere. T'he fold belts, such as Altai, Qinlin belt, North-South tectonic belt, southeast continental margin, South China sea, East China sea. Ryukyu trench represented by thin lithosphere.In the lower mantle (depth in 700-1200 km) the velocity distribution shows the northsouth trend. The high velocity regions are presented in the Japan sea and East China sea, and also appear in the N-S tectonic belt through out central China. In the depth 2200-2800 km close the CMB region a huge high velocity anomaly is distributed from east to west, this could be explained as a super cold downwelling plume in the east and central Asia.The super downwelling plume underneath Asia is the dominant pattern of vertical mantle flow in the modem Earth. This huge cold plume is formed by the multi-subduction of oceanic plates of paleo Tethys and Pacific, the cold slabs was supplied by plates at trench and down to lower part of upper mantle (670 km in depth), where they were accumulated, and after a geologically significant time the stagnant mass of cold slabs gravitationally collapsed onto the CMB. Once it is formed in lower mantle, the mantle convection patterns in the upper mantle tends to be strongly controlled by a sole downwelling superplume in the lower mantle. Thus all continents tend to be swallowed into the cold superplume until they are collision and amalgamation to form a super-continent.The central Asia, from Indian subcontinent to Tibet, Xijiang, Mongolia and Baikal regions are the present largest convergence place in the world. there are thicken crust and lithosphere, showing high compressional stress in the crust, low heat flow and broad distributed earthquakes, and negative gravity anomaly, lowest geoid,all of these characteristics indicate the mantle materials fall down to the CMB and continents converged in this region.
引文
[1]朱介寿,我国大陆岩石圈的地震学研究,见:中国地质科学院主编,岩石圈研究基本问题和方法,318-327,北京:冶金工业出版社,1991.
[2]朱介寿,我国大陆地壳及土地幔分块结构特征,成都地质学院学报,13,75-94,1986.
[3]朱介寿、严忠琼、徐思聪,上、中、下地壳及上地幔顶面地震波速度图,见:袁学诚主编,中国地球物理图集,北京:地质出版社,170-173,1996.
[4]朱介寿、严忠琼、姚宇峰,莫霍界面深度图,见:袁学诚主编,中国地球物理图集,北京:地质出版社,176-1771996.
[5]冯锐、朱介寿、丁韫玉等,利用地震面波研究中国地壳结构,地震学报,3,335-350,1981.
[6]朱介寿、严忠琼、徐思聪,上地幔低速层顶界面深度图,见:袁学诚主编,中国地球物理图集,北京:地质出版社,178-179,1996.
[7]孙若昧、刘福田、刘建华,四川地区的地震层析成像,地球物理学报,34, 708-716,1991.
[8]孙若昧、赵燕来、梅世容,渤海及其临近地区的地震层析成像,地球物理学报, 36,44-54 1993.
[9]周兵、朱介寿、秦建业,青藏高原及邻近区域S波三维速度结构,地球物理学报,34,426-441,1991.
[10]刘福田、曲克信、吴华等,中国大陆及其邻近地区的地震层析成像,地球物理学报,32,281-291,1989.
[11]刘福田、刘建华,体波地震层析成像,见:袁学诚主编,中国地球物理图集,北京:地质出版社,174-175,1996.
[12]刘福田、李强、刘建华等,日本及其毗邻地区的地震层析成像,地球物理学报编辑委员会,八十年代中国地球物理学进展,北京:学术出版社,1989.
[13]宋仲和、安昌强、陈国英等,中国西部三维速度结构及其各向异性,地球物理学报,34,694-707,1991.
[14]庄真、傅竹武、吕梓龄等,青藏高原及邻近地区地壳与上地幔剪切波三维速度结构,地球物理学报,35, 694-709,1992.
[15]安昌强、朱仲和、陈国英等,中国西北地区剪切波三维速度结构,地球物理学报,36,317-325,1993.
[16]宋仲和、陈国英、安昌强等,中国大陆及其海域地壳-上地幔三维速度结构,中国科学(B),23,180-188,1993.
[17]宋仲和、陈国英、安昌强等,中国东部及其相邻海域S波三维速度结构,地球物理学报,35,316-329, 1992.
[18]陈立华、宋仲和、安昌强等,中国南北带地壳上地幔三维面波速度结构和各向异性,地球物理学报,35,574-583,1992.
[19]曾融生、朱介寿、周兵等,青藏高原及其东部邻区的三维地震波速度结构与大陆碰撞模型,地震学报,14(增刊),523-533,1992.
[20]国家地震局科技监测司编,中国大陆深部构造的研究与进展,北京:地质出版社,1988.
[21]国家地震局“深部物探成果”编写组,中国地壳上地幔地球物理探测成果,北京:地震出版社,1986.
[22]郑晔、滕古文,随县-马鞍山地带地壳与上地幔结构及郯庐构造南段的某些特征,地球物理学报,32,648-659,1989.
[23]汤永安主编,华北平原南部地区深部地球物理综合探测方法与成果,北京:海洋出版社,1989.
[24]丁原章、李坪、时振梁等编,海南岛北部地震研究文集,北京;地震出版社,1988.
[25]胡鸿翔、陆涵行、王椿镛等,滇西地区地壳结构的爆破地震研究,地球物理学报,29, 133-143,1986.
[26]崔作舟、卢德源等,攀西地区的深部地壳结构与构造,地球物理学报,30,566-579, 1987.
[27]Dziewonski, A. M., Mapping the lower mantle: Determination of lateral heterogeneity in P velocity up to degree and order 6, J. Geophys. Res., 89, 5929-5952, 1984.
[28]Dziewonski, A. M., Woodhouse, J., Global images of the Earth's interior, Science, 236, 37-48, 1987.
[29]Nataf H. C., Nakanish, I., Anderson, D L., Measurements of mantle wave velocities and inversion for lateral heterogeneties and anisotropy: Ⅲ, Inversion, J. Geophys, Res., 91, 7261-7308, 1986.
[30]Woodhouse, J. H., Dziewonski, A. M., Mapping the upper mantle: Three dimensional modeling of earth structure by inversion of seismic waveforms, J. Geophys. Res., 89, 5953-5986, 1984.
[31]Tenimoto, T., Structure of the Earth and its dynamics, Science(Japan), 59, 88-95, 1989.
[32]Montagner, J. P., Can seismology tell us anything about convection in the mantle?, Rev. of Geophys., 32,115-137, 1994.
[33]Montagner, J. P., Tanimoto, T., Global upper mantle tomography of seismic velocities and anisotropies, J.Geophys. Res., 96, 20337-20351, 1991.
[34]Nataf H. C., Mantle convection, plates, and hotspots, Tectonophysics, 187, 361-371, 1991.
[35]Davies, G. E., Richards, M. A., Mantle convection, J. Geol., 100, 151-206, 1992.
[36]Hager, B. H., Richards, M. A. Long-wavelength variation in Earth's geoid: physical models and dynamical implications, Trans. Royal. Soc. Lond., A328, 309-327, 1989.
[37]Hager, B. H., Clayton, R. W., Richards, R. W., et al., Lower mantle heterogeneity, dynamic topography and geoid, Nature, 313, 541-545, 1985.
[38]Inoue, H., Fukao, Y., Tanabe, K., Ogata, Y., Whole mantle P-wave travel time tomographuy, Phys. Earth Planet. Inter., 59, 294-328, 1990.
[39]Zhang, Y., Tanimoto, T., High-resolution global upper mantle structure, plate tectonics, J. Geophys. Res.,98, 9793-9823, 1993.
[40]Fukao, Y., Maruyama, S., Obnyashi, M, et al., Geologic implication of the whole mantle P-wave tomography, J. Geol. Soc. Japan, 100, 4-23, 1994.
[41]Maruyama, S., Plume tectonics, J. Geol. Soc. Japan, 100, 24-29, 1994.
[42]Fukao, Y., Seismic tomogrm of the Earth's mantle: Geodynamic implications, Science(Japan), 258, 625-630, 1992.
[43]Ritzwoller, M. H., Lavely, E. M., Three-Dimesional seismic Models of the Earth's mantle, Rev. of Geophys., 33, 1, 1-66, 1995.
[2]朱介寿,我国大陆地壳及土地幔分块结构特征,成都地质学院学报,13,75-94,1986.
[3]朱介寿、严忠琼、徐思聪,上、中、下地壳及上地幔顶面地震波速度图,见:袁学诚主编,中国地球物理图集,北京:地质出版社,170-173,1996.
[4]朱介寿、严忠琼、姚宇峰,莫霍界面深度图,见:袁学诚主编,中国地球物理图集,北京:地质出版社,176-1771996.
[5]冯锐、朱介寿、丁韫玉等,利用地震面波研究中国地壳结构,地震学报,3,335-350,1981.
[6]朱介寿、严忠琼、徐思聪,上地幔低速层顶界面深度图,见:袁学诚主编,中国地球物理图集,北京:地质出版社,178-179,1996.
[7]孙若昧、刘福田、刘建华,四川地区的地震层析成像,地球物理学报,34, 708-716,1991.
[8]孙若昧、赵燕来、梅世容,渤海及其临近地区的地震层析成像,地球物理学报, 36,44-54 1993.
[9]周兵、朱介寿、秦建业,青藏高原及邻近区域S波三维速度结构,地球物理学报,34,426-441,1991.
[10]刘福田、曲克信、吴华等,中国大陆及其邻近地区的地震层析成像,地球物理学报,32,281-291,1989.
[11]刘福田、刘建华,体波地震层析成像,见:袁学诚主编,中国地球物理图集,北京:地质出版社,174-175,1996.
[12]刘福田、李强、刘建华等,日本及其毗邻地区的地震层析成像,地球物理学报编辑委员会,八十年代中国地球物理学进展,北京:学术出版社,1989.
[13]宋仲和、安昌强、陈国英等,中国西部三维速度结构及其各向异性,地球物理学报,34,694-707,1991.
[14]庄真、傅竹武、吕梓龄等,青藏高原及邻近地区地壳与上地幔剪切波三维速度结构,地球物理学报,35, 694-709,1992.
[15]安昌强、朱仲和、陈国英等,中国西北地区剪切波三维速度结构,地球物理学报,36,317-325,1993.
[16]宋仲和、陈国英、安昌强等,中国大陆及其海域地壳-上地幔三维速度结构,中国科学(B),23,180-188,1993.
[17]宋仲和、陈国英、安昌强等,中国东部及其相邻海域S波三维速度结构,地球物理学报,35,316-329, 1992.
[18]陈立华、宋仲和、安昌强等,中国南北带地壳上地幔三维面波速度结构和各向异性,地球物理学报,35,574-583,1992.
[19]曾融生、朱介寿、周兵等,青藏高原及其东部邻区的三维地震波速度结构与大陆碰撞模型,地震学报,14(增刊),523-533,1992.
[20]国家地震局科技监测司编,中国大陆深部构造的研究与进展,北京:地质出版社,1988.
[21]国家地震局“深部物探成果”编写组,中国地壳上地幔地球物理探测成果,北京:地震出版社,1986.
[22]郑晔、滕古文,随县-马鞍山地带地壳与上地幔结构及郯庐构造南段的某些特征,地球物理学报,32,648-659,1989.
[23]汤永安主编,华北平原南部地区深部地球物理综合探测方法与成果,北京:海洋出版社,1989.
[24]丁原章、李坪、时振梁等编,海南岛北部地震研究文集,北京;地震出版社,1988.
[25]胡鸿翔、陆涵行、王椿镛等,滇西地区地壳结构的爆破地震研究,地球物理学报,29, 133-143,1986.
[26]崔作舟、卢德源等,攀西地区的深部地壳结构与构造,地球物理学报,30,566-579, 1987.
[27]Dziewonski, A. M., Mapping the lower mantle: Determination of lateral heterogeneity in P velocity up to degree and order 6, J. Geophys. Res., 89, 5929-5952, 1984.
[28]Dziewonski, A. M., Woodhouse, J., Global images of the Earth's interior, Science, 236, 37-48, 1987.
[29]Nataf H. C., Nakanish, I., Anderson, D L., Measurements of mantle wave velocities and inversion for lateral heterogeneties and anisotropy: Ⅲ, Inversion, J. Geophys, Res., 91, 7261-7308, 1986.
[30]Woodhouse, J. H., Dziewonski, A. M., Mapping the upper mantle: Three dimensional modeling of earth structure by inversion of seismic waveforms, J. Geophys. Res., 89, 5953-5986, 1984.
[31]Tenimoto, T., Structure of the Earth and its dynamics, Science(Japan), 59, 88-95, 1989.
[32]Montagner, J. P., Can seismology tell us anything about convection in the mantle?, Rev. of Geophys., 32,115-137, 1994.
[33]Montagner, J. P., Tanimoto, T., Global upper mantle tomography of seismic velocities and anisotropies, J.Geophys. Res., 96, 20337-20351, 1991.
[34]Nataf H. C., Mantle convection, plates, and hotspots, Tectonophysics, 187, 361-371, 1991.
[35]Davies, G. E., Richards, M. A., Mantle convection, J. Geol., 100, 151-206, 1992.
[36]Hager, B. H., Richards, M. A. Long-wavelength variation in Earth's geoid: physical models and dynamical implications, Trans. Royal. Soc. Lond., A328, 309-327, 1989.
[37]Hager, B. H., Clayton, R. W., Richards, R. W., et al., Lower mantle heterogeneity, dynamic topography and geoid, Nature, 313, 541-545, 1985.
[38]Inoue, H., Fukao, Y., Tanabe, K., Ogata, Y., Whole mantle P-wave travel time tomographuy, Phys. Earth Planet. Inter., 59, 294-328, 1990.
[39]Zhang, Y., Tanimoto, T., High-resolution global upper mantle structure, plate tectonics, J. Geophys. Res.,98, 9793-9823, 1993.
[40]Fukao, Y., Maruyama, S., Obnyashi, M, et al., Geologic implication of the whole mantle P-wave tomography, J. Geol. Soc. Japan, 100, 4-23, 1994.
[41]Maruyama, S., Plume tectonics, J. Geol. Soc. Japan, 100, 24-29, 1994.
[42]Fukao, Y., Seismic tomogrm of the Earth's mantle: Geodynamic implications, Science(Japan), 258, 625-630, 1992.
[43]Ritzwoller, M. H., Lavely, E. M., Three-Dimesional seismic Models of the Earth's mantle, Rev. of Geophys., 33, 1, 1-66, 1995.
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