云南思茅—中甸地震剖面的地壳结构
|
摘要
云南思茅—中甸宽角反射/折射地震剖面切割松潘—甘孜、扬子和华南三个构造单元的部分区域.我们利用初至波和壳内反射波走时层析成像获得地壳纵波速度结构.在获得新的地壳速度结构模型基础上,利用地震散射成像思想和低叠加次数的叠前深度偏移方法重建了研究区的地壳、上地幔反射结构.综合分析研究区地壳P波速度模型和壳内地震反射剖面发现:沿测线从北至南地壳厚度从约50 km减薄至35 km左右,地壳厚度的减薄量主要体现在下地壳,剖面北段下地壳厚度约为30 km,剖面南段下地壳厚度仅为15 km左右;上地幔顶部局部位置P波速度值偏低,一般为7.6~7.8 km/s,反映出云南地区是典型的构造活动区的特点.剖面沿线地壳内地震反射发育,其中莫霍强反射出现在景云桥下方;在景云桥弧形断裂带8~10 km深处出现宽约50 km的强反射带.
The wide-angle seismic reflection/refraction profile between Simao and Zhongdian in Yunnan crosses Songpan-Garzê,Yangtze and Cathaysia blocks.By means of seismic traveltime tomography we used first arrivals and other reflections from interfaces in the crust to obtain crustal P-wave velocity structure,and then reconstructed crust-upper mantle seismic reflection structure by using the low-fold pre-stack migration in depth domain and seismic scattering scheme on the basis of the above-mentioned crustal P-wave velocity model.By analyzing crustal P-wave velocity model and crustal seismic reflection structure,we can conclude that crustal thickness thins from about 50 km under the north segment of the profile to about 35 km on the south of the profile,the thinning occurs mainly in the lower crust,where the lower crustal thickness is about 30 km in the north segment,and about 15 km in the south segment;along the profile P-wave velocity in the uppermost mantle is about 7.6～7.8 km/s,which is lower than average and indicates the characters of a typical tectonically active area.The reflection wave is developed within crust,a strong reflection zone of Moho exists beneath Jingyunqiao fault,and a strong reflection zone about 50 km wide is located at a depth of 8～10 km beneath Jingyunqiao fault.
The wide-angle seismic reflection/refraction profile between Simao and Zhongdian in Yunnan crosses Songpan-Garzê,Yangtze and Cathaysia blocks.By means of seismic traveltime tomography we used first arrivals and other reflections from interfaces in the crust to obtain crustal P-wave velocity structure,and then reconstructed crust-upper mantle seismic reflection structure by using the low-fold pre-stack migration in depth domain and seismic scattering scheme on the basis of the above-mentioned crustal P-wave velocity model.By analyzing crustal P-wave velocity model and crustal seismic reflection structure,we can conclude that crustal thickness thins from about 50 km under the north segment of the profile to about 35 km on the south of the profile,the thinning occurs mainly in the lower crust,where the lower crustal thickness is about 30 km in the north segment,and about 15 km in the south segment;along the profile P-wave velocity in the uppermost mantle is about 7.6～7.8 km/s,which is lower than average and indicates the characters of a typical tectonically active area.The reflection wave is developed within crust,a strong reflection zone of Moho exists beneath Jingyunqiao fault,and a strong reflection zone about 50 km wide is located at a depth of 8～10 km beneath Jingyunqiao fault.
引文
[1]潘浴生.青藏高原西北部大地构造演化.见:中国科学院地质研究所岩石构造演化开放研究实验室1989-1990年报.北京:中国科学技术出版社,1991Pan Y S.The evolution of the tectonic structure in north-west TibetanPlateau,In:The Exoteric Laboratory of Structure Evolution of theLithosphere of Institute of Geology and Geophysics Academy ofSciences,1989-1990 Annual Report(in Chinese),Beijing:Chinese Science and Technology Press,1991
[2]张中杰,滕吉文,李英康等.藏南地壳结构和地壳物质东西向“逃逸”.中国科学(D辑),2002,32(10):793~798Zhang Z J,Teng J W,Li Y K,et al.Crustal structure of seismicvelocity in southern Tibet and east-westward escape of the crustalmaterial.Science in China(Series D),2004,47(6):500~506
[3]李兴振,刘增乾,潘桂棠等.西南三江地区大地构造单元划分及地史演化.见:中国地质科学院成都地质矿产研究所所刊(13).北京:地质出版社,1991Li X Z,Liu Z K,Pan G T,et al.Units partition of tectonicstructure and evolution of earth history in southwest Sanjiang region.In:Acta of Chengdu Geology and Commodity Institute of ChineseAcademy of Geosciences(13)(in Chinese).Beijing:GeologicalPublishing House,1991
[4]钟大赉,丁林.从三江及邻区特提斯演化讨论冈瓦纳大陆离散与亚洲大陆增生,亚洲的增生.北京:地震出版社,1993.5~8Zhong D L,Ding L.To Discuss Gondawana Continent Disperse,Asian Continent Hyperplasia and Asian Hyperplasia from TethysEvolution in Sanjiang and Its Neighbor(in Chinese).Beijing:Seismological Press,1993.5~8
[5]HsüK J,Bernoulli D.Genesis of the Tethys and Mediterranean.In:HsüK J,Montadart L,et al.eds.Initial Reports of Deep SeaDrilling Project,1978,42(1):943~949
[6]Seng r A M C.The evolution of Paleo-Tethys in the Tibetan segmentof the Alpides.In:Geological and Ecological Studies of Qinghai-Tibet Plateau.Beijing:Science Press,1981,51~56
[7]高锐.青藏高原地壳上地幔地球物理研究成果综述(上、下).中国地质,2000,(4):26~28;(5):20~220Gao R.An introduction to geophysical study of the crust and uppermantle on the Tibetan Plateau area(a,b).Geology in China(inChinese),2000,(4):26~28;(5):20~220
[8]黄汲清,陈炳蔚.中国及邻区特提斯海的演化.北京:地质出版社,1987Huang J Q,Chen B W.Evolution of Tethys in China andNeighbouring Region(in Chinese).Beijing:Geological PublishingHouse,1987
[9]钟大赉,丁林,刘福田等.造山带岩石层多向层架构造及其对新生代岩浆活动制约-以三江及邻区为例.中国科学(D辑),2000,30(增刊):1~8Zhong D L,Ding L,Liu F T,et al.Orogen and lithosphere multi-direction layer frame structure and restriction to magma activity inCenozoic—an example by Sanjiang and its neighbouring region.Science in China(Series D)(in Chinese),2000,30(Suppl.):1~8
[10]林中洋,胡鸿翔,张文彬等.滇西地区地壳上地幔速度结构特征的研究.地震学报,1993,15(4):427~440Lin Z Y,Hu H X,Zhang W B,et al.A study on velocity structureof the crust and upper mantle in Dianxi region,Acta SeismologicaSinica(in Chinese),1993,15(4):427~440
[11]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,1986,29(2):133~143Hu H X,Lu H X,Wang C Y,et al.A study on crustal structure andbreakout seismology in Dianxi region.Chinese J.Geophys.(inChinese),1986,29(2):133~144
[12]白志明,王椿镛.云南遮放-宾川和孟连-马龙宽角地震剖面的层析成像研究.地球物理学报,2004,47(2):257~267Bai Z M,Wang C Y.Tomography research of the Zhefang-Binchuanand Menglian-Malong wide-angle seismic profiles in Yunnan.ChineseJ.Geophys.(in Chinese),2004,47(2):257~267
[13]白志明,王椿镛.云南地区上部地壳结构和地震构造环境的层析成像研究.地震学报,2003,25(2):117~127Bai Z M,Wang C Y.Structure of the upper crust and tomography ofseismic tectonic condition in Yunnan.Acta Seismologica Sinica(inChinese),2003,25(2):117~127
[14]Ammon C J,Vidate J E.Tomography without rays.Bull.Seism.Soc.Amer.,1993,83:509~528
[15]张中杰,秦义龙,陈等.由宽角反射地震资料重建壳幔反射结构的相似性剖面.地球物理学报,2004,47(3):469~474Zhang Z J,Qin Y L,Chen Y,et al.Reconstruction of the semblancesection for the crust and mantle reflection structure by wide-anglereflection seismic data.Chinese J.Geophys.(in Chinese),2004,47(3):469~474
[16]彭兴阶,刘嘉惠,吴精汇.怒江-澜沧江-金沙江地区地质.北京:地质出版社,1998.105Peng X J,Liu J H,Wu J H.The Geology in Nujiang-Lancang-Jinshajiang Region(in Chinese).Beijing:Geological PublishingHouse,1998.105
[17]胡家富,苏有锦,朱雄关等.云南地壳S波速度与泊松比结构及其意义.中国科学(D辑),2003,33(8):714~722Hu J F,Su Y J,Zhu X G,et al.S-wave velocity of the crust and thestructure of Possion ratio in Yunnan and meanings.Science in China(Series D)(in Chinese),2003,33(8):714~722
[18]张中杰,白志明,王椿镛等.冈瓦纳型和扬子型地块地壳结构:以滇西孟连-马龙宽角反射剖面为例.中国科学(D辑),2005,35(4):387~392Zhang Z J,Bai Z M,Wang C Y,et al.The crustal structure ofGondawana and Yangtze blocks:An example by wide angel seismicreflection profiling between Menglian and Malong.Science in China(Serial D),2005,48(11):1828~1836
[19]张中杰,白志明,王椿镛等.三江地区地壳结构及动力学意义:云南遮放-宾川地震反射/折射剖面的启示.中国科学(D辑),2005,48(9):314~319Zhang Z J,Bai Z M,Wang C Y,et al.The crustal structure underSanjiang and its dynamic implications:Revealed by seismicreflection/refraction profiling between Zhefang and Binchuan,Yunnan.Science in China(Series D),2005,48(9):1329~1336
[20]胡家富,朱雄关,夏静瑜,陈.利用面波和接收函数资料联合反演滇西地区壳幔速度结构.地球物理学报,2005,48(5):1069~1076Hu J F,Zhu X G,Xia J Y,Chen Y.Using surface wave and receiverfunction to jointly inverse the crust-mantle velocity structure in theWest Yunnan area.Chinese J.Geophys.(in Chinese),2005,48(5):1069~1076
[21]王椿镛,楼海,吴建平等.腾冲火山地热区地壳结构的地震学研究.地震学报,2002,24(3):231~242Wang C Y,Lou H,Wu J P,et al.Seismological study on the crustalstructure of Tengchong volcano-geothermal area.Acta SeismologicaSinca(in Chinese),2002,24(3):231~242
[22]刘,张中杰,胡家富等.中国陆区S波分裂的频带相关性及其意义.中国科学(D辑),2001,31(2):155~161Liu K,Zhang Z J,Hu J F,et al.Meanings and frequency bandrelation of S-wave splitting in mainland China.Science in China(Series D)(in Chinese),2001,31(2):155~161
[23]石玉涛,高原,吴晶等.云南地区地壳介质各向异性-快剪切波特性初步研究.地震学报,2006,出版中Shi Y T,Gao Y,Wu J,et al.An elementary study on the anisotropyof crust-the characteristic of quasi transversal wavepiece correction inYunnan.Acta Seismologica Sinca(in Chinese),2006,in press.
[24]熊绍柏,刘宏兵,王有学等.华南上地壳速度分布与基底、盖层构造研究.地球物理学报,2002,45(6):784~791Xiong S B,Liu H B,Wang Y X,et al.A study on velocitydistribution in upper crust and tectonics of basement and cover insouth China.Chinese J.Geophys.(in Chinese),2002,45(6):784~791
[25]尹周勋,赖明惠,熊绍柏等.华南连县-博罗-港口地带地壳结构及速度分布的爆炸地震探测结果.地球物理学报,1999,42(3):383~392Yin Z X,Lai M H,Xiong S B,et al.Crustal structure and velocitydistribution from deep seismic sounding along the profile of Lianxian-Boluo-Gangkou in south China.Chinese J.Geophys.(in Chinese),1999,42(3):383~392
[26]熊绍柏.中国东南地区的岩石圈结构、岩石圈构造演化.见:李继亮主编.中国东南海陆岩石圈结构与演化研究.北京:中国科学技术出版社,1992.267~277Xiong S B.The structure and tectonic evolution of lithosphere insoutheastern China.In:Li J L ed.Structure and Evolution ofLithosphere in Southeastern China(in Chinese).Beijing:ChineseScience and Technology Press,1992.267~277
[27]Zhang Z J,Badal J,Li Y K,et al.Crust-upper mantle seismic wavevelocity structure across southerneastern China.Tectonophysics,2005,395:137~157
[2]张中杰,滕吉文,李英康等.藏南地壳结构和地壳物质东西向“逃逸”.中国科学(D辑),2002,32(10):793~798Zhang Z J,Teng J W,Li Y K,et al.Crustal structure of seismicvelocity in southern Tibet and east-westward escape of the crustalmaterial.Science in China(Series D),2004,47(6):500~506
[3]李兴振,刘增乾,潘桂棠等.西南三江地区大地构造单元划分及地史演化.见:中国地质科学院成都地质矿产研究所所刊(13).北京:地质出版社,1991Li X Z,Liu Z K,Pan G T,et al.Units partition of tectonicstructure and evolution of earth history in southwest Sanjiang region.In:Acta of Chengdu Geology and Commodity Institute of ChineseAcademy of Geosciences(13)(in Chinese).Beijing:GeologicalPublishing House,1991
[4]钟大赉,丁林.从三江及邻区特提斯演化讨论冈瓦纳大陆离散与亚洲大陆增生,亚洲的增生.北京:地震出版社,1993.5~8Zhong D L,Ding L.To Discuss Gondawana Continent Disperse,Asian Continent Hyperplasia and Asian Hyperplasia from TethysEvolution in Sanjiang and Its Neighbor(in Chinese).Beijing:Seismological Press,1993.5~8
[5]HsüK J,Bernoulli D.Genesis of the Tethys and Mediterranean.In:HsüK J,Montadart L,et al.eds.Initial Reports of Deep SeaDrilling Project,1978,42(1):943~949
[6]Seng r A M C.The evolution of Paleo-Tethys in the Tibetan segmentof the Alpides.In:Geological and Ecological Studies of Qinghai-Tibet Plateau.Beijing:Science Press,1981,51~56
[7]高锐.青藏高原地壳上地幔地球物理研究成果综述(上、下).中国地质,2000,(4):26~28;(5):20~220Gao R.An introduction to geophysical study of the crust and uppermantle on the Tibetan Plateau area(a,b).Geology in China(inChinese),2000,(4):26~28;(5):20~220
[8]黄汲清,陈炳蔚.中国及邻区特提斯海的演化.北京:地质出版社,1987Huang J Q,Chen B W.Evolution of Tethys in China andNeighbouring Region(in Chinese).Beijing:Geological PublishingHouse,1987
[9]钟大赉,丁林,刘福田等.造山带岩石层多向层架构造及其对新生代岩浆活动制约-以三江及邻区为例.中国科学(D辑),2000,30(增刊):1~8Zhong D L,Ding L,Liu F T,et al.Orogen and lithosphere multi-direction layer frame structure and restriction to magma activity inCenozoic—an example by Sanjiang and its neighbouring region.Science in China(Series D)(in Chinese),2000,30(Suppl.):1~8
[10]林中洋,胡鸿翔,张文彬等.滇西地区地壳上地幔速度结构特征的研究.地震学报,1993,15(4):427~440Lin Z Y,Hu H X,Zhang W B,et al.A study on velocity structureof the crust and upper mantle in Dianxi region,Acta SeismologicaSinica(in Chinese),1993,15(4):427~440
[11]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,1986,29(2):133~143Hu H X,Lu H X,Wang C Y,et al.A study on crustal structure andbreakout seismology in Dianxi region.Chinese J.Geophys.(inChinese),1986,29(2):133~144
[12]白志明,王椿镛.云南遮放-宾川和孟连-马龙宽角地震剖面的层析成像研究.地球物理学报,2004,47(2):257~267Bai Z M,Wang C Y.Tomography research of the Zhefang-Binchuanand Menglian-Malong wide-angle seismic profiles in Yunnan.ChineseJ.Geophys.(in Chinese),2004,47(2):257~267
[13]白志明,王椿镛.云南地区上部地壳结构和地震构造环境的层析成像研究.地震学报,2003,25(2):117~127Bai Z M,Wang C Y.Structure of the upper crust and tomography ofseismic tectonic condition in Yunnan.Acta Seismologica Sinica(inChinese),2003,25(2):117~127
[14]Ammon C J,Vidate J E.Tomography without rays.Bull.Seism.Soc.Amer.,1993,83:509~528
[15]张中杰,秦义龙,陈等.由宽角反射地震资料重建壳幔反射结构的相似性剖面.地球物理学报,2004,47(3):469~474Zhang Z J,Qin Y L,Chen Y,et al.Reconstruction of the semblancesection for the crust and mantle reflection structure by wide-anglereflection seismic data.Chinese J.Geophys.(in Chinese),2004,47(3):469~474
[16]彭兴阶,刘嘉惠,吴精汇.怒江-澜沧江-金沙江地区地质.北京:地质出版社,1998.105Peng X J,Liu J H,Wu J H.The Geology in Nujiang-Lancang-Jinshajiang Region(in Chinese).Beijing:Geological PublishingHouse,1998.105
[17]胡家富,苏有锦,朱雄关等.云南地壳S波速度与泊松比结构及其意义.中国科学(D辑),2003,33(8):714~722Hu J F,Su Y J,Zhu X G,et al.S-wave velocity of the crust and thestructure of Possion ratio in Yunnan and meanings.Science in China(Series D)(in Chinese),2003,33(8):714~722
[18]张中杰,白志明,王椿镛等.冈瓦纳型和扬子型地块地壳结构:以滇西孟连-马龙宽角反射剖面为例.中国科学(D辑),2005,35(4):387~392Zhang Z J,Bai Z M,Wang C Y,et al.The crustal structure ofGondawana and Yangtze blocks:An example by wide angel seismicreflection profiling between Menglian and Malong.Science in China(Serial D),2005,48(11):1828~1836
[19]张中杰,白志明,王椿镛等.三江地区地壳结构及动力学意义:云南遮放-宾川地震反射/折射剖面的启示.中国科学(D辑),2005,48(9):314~319Zhang Z J,Bai Z M,Wang C Y,et al.The crustal structure underSanjiang and its dynamic implications:Revealed by seismicreflection/refraction profiling between Zhefang and Binchuan,Yunnan.Science in China(Series D),2005,48(9):1329~1336
[20]胡家富,朱雄关,夏静瑜,陈.利用面波和接收函数资料联合反演滇西地区壳幔速度结构.地球物理学报,2005,48(5):1069~1076Hu J F,Zhu X G,Xia J Y,Chen Y.Using surface wave and receiverfunction to jointly inverse the crust-mantle velocity structure in theWest Yunnan area.Chinese J.Geophys.(in Chinese),2005,48(5):1069~1076
[21]王椿镛,楼海,吴建平等.腾冲火山地热区地壳结构的地震学研究.地震学报,2002,24(3):231~242Wang C Y,Lou H,Wu J P,et al.Seismological study on the crustalstructure of Tengchong volcano-geothermal area.Acta SeismologicaSinca(in Chinese),2002,24(3):231~242
[22]刘,张中杰,胡家富等.中国陆区S波分裂的频带相关性及其意义.中国科学(D辑),2001,31(2):155~161Liu K,Zhang Z J,Hu J F,et al.Meanings and frequency bandrelation of S-wave splitting in mainland China.Science in China(Series D)(in Chinese),2001,31(2):155~161
[23]石玉涛,高原,吴晶等.云南地区地壳介质各向异性-快剪切波特性初步研究.地震学报,2006,出版中Shi Y T,Gao Y,Wu J,et al.An elementary study on the anisotropyof crust-the characteristic of quasi transversal wavepiece correction inYunnan.Acta Seismologica Sinca(in Chinese),2006,in press.
[24]熊绍柏,刘宏兵,王有学等.华南上地壳速度分布与基底、盖层构造研究.地球物理学报,2002,45(6):784~791Xiong S B,Liu H B,Wang Y X,et al.A study on velocitydistribution in upper crust and tectonics of basement and cover insouth China.Chinese J.Geophys.(in Chinese),2002,45(6):784~791
[25]尹周勋,赖明惠,熊绍柏等.华南连县-博罗-港口地带地壳结构及速度分布的爆炸地震探测结果.地球物理学报,1999,42(3):383~392Yin Z X,Lai M H,Xiong S B,et al.Crustal structure and velocitydistribution from deep seismic sounding along the profile of Lianxian-Boluo-Gangkou in south China.Chinese J.Geophys.(in Chinese),1999,42(3):383~392
[26]熊绍柏.中国东南地区的岩石圈结构、岩石圈构造演化.见:李继亮主编.中国东南海陆岩石圈结构与演化研究.北京:中国科学技术出版社,1992.267~277Xiong S B.The structure and tectonic evolution of lithosphere insoutheastern China.In:Li J L ed.Structure and Evolution ofLithosphere in Southeastern China(in Chinese).Beijing:ChineseScience and Technology Press,1992.267~277
[27]Zhang Z J,Badal J,Li Y K,et al.Crust-upper mantle seismic wavevelocity structure across southerneastern China.Tectonophysics,2005,395:137~157
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心