青藏高原下地壳热变形和管道流研究
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摘要
本文应用地球三维成像方法和现代物理学的理论,来说明青藏高原下地壳管道流形成的原因和条件。根据区域重力资料提取的地壳三维密度成像的信息,进一步探讨了青藏高原地壳低密度扰动带反映的地质构造。应用地壳三维密度图像,分析了青藏高原下地壳为什么会形成管道流的原因,圈定了下地壳管道流所在位置。通过连续介质物理学的理论分析了热变形带如何引起下地壳管道流的机制,给出通过密度扰动计算了下地壳热应变率的方程式。结果表明,青藏高原下地壳管道流的热应变幅度大约为15.5mm~3/a。按照方程式和下地壳的密度扰动数据计算了青藏高原下地壳热应变幅度分布图。图中正热应变幅度代表热膨胀,负热应变幅度代表冷收缩;下地壳管道流随应变率从高向低流动。下地壳岩石热应变率最高处指示下地壳管道流的源头,位于喀拉昆仑断裂东侧与雅鲁藏布至班公—怒江缝合带的连接区段,和雅鲁藏布缝合带北侧的拉孜—林芝段。从喀拉昆仑断裂东侧源头的下地壳管道流主要流向北东和北西两个方向。从雅鲁藏布缝合带北侧源头的下地壳管道流主要流向北东到理塘—雅江和滇北地区,然后又分为南北两个方向分流。下地壳管道流位置或可向上挤出到中地壳,引起青藏高原重力不均衡和山脉隆升。同时,三维密度成像的结果支持下地壳流牙膏式向上挤出的蠕动模式。
Objectives:Based on the crustal density images obtained in Qinghai—Xizang(Tibet) Plateau that we presented by previous papers,a study of causes and sources of low-density belts in the studied area is analyzed fin this paper.Methods:The basic theory about thermal stress in continuum physics is applied for the analysis and links todata of lithospheric investigations,aiming at formation mechanics of lowercrustal channel flow.Corresponding functions linking the thermal strain,temperature and density variation in the Lower crust provide the possibility of estimating the Lower crustal thermal strain maps,providing important evidences for study of the channel flows and mass movement.Results:Applying the methods produce the results that the maximum thermal strain of this channel flow caused by heat expansion equals to 15.5mm~3/a.And the resulting map shows that positive thermal strain indicates expansion areas of the Lower crust in the studied area,whilst negative thermal strain indicates cold contraction areas.The lowercrustal channel flows originate from two sources that characterized by areas of the highest thermal strain,then flow into areas of the lower thermal strain.The areas of the highest thermal strain are located at two places,the first is by the eastern side of the Karakoran fault between the Bangong—Nujiang and the Yaluzangbo sutures.The second flow source is located by the northern side of the Yaluzangbo suture between Lhaze—Nyingchi.The channel flows originates from the first source goes to NE and NW,i.e.,to Aljin area and Karakoran area respectively.The channel flows originates from the second source goes to east,reaching to Litang—Yajiang area and North Yunnan,then diversely flows to north and south.Conclusions:The study supports the hypothesis of the Lower crust channel flows and diapiric intrusions of the flow from the Lower crust into the middle crust like dental cream,which have been resulting in break of gravitational equilibrium and uplifting of mountains in Qinghai—Xizang(Tibet) Plateau.
Objectives:Based on the crustal density images obtained in Qinghai—Xizang(Tibet) Plateau that we presented by previous papers,a study of causes and sources of low-density belts in the studied area is analyzed fin this paper.Methods:The basic theory about thermal stress in continuum physics is applied for the analysis and links todata of lithospheric investigations,aiming at formation mechanics of lowercrustal channel flow.Corresponding functions linking the thermal strain,temperature and density variation in the Lower crust provide the possibility of estimating the Lower crustal thermal strain maps,providing important evidences for study of the channel flows and mass movement.Results:Applying the methods produce the results that the maximum thermal strain of this channel flow caused by heat expansion equals to 15.5mm~3/a.And the resulting map shows that positive thermal strain indicates expansion areas of the Lower crust in the studied area,whilst negative thermal strain indicates cold contraction areas.The lowercrustal channel flows originate from two sources that characterized by areas of the highest thermal strain,then flow into areas of the lower thermal strain.The areas of the highest thermal strain are located at two places,the first is by the eastern side of the Karakoran fault between the Bangong—Nujiang and the Yaluzangbo sutures.The second flow source is located by the northern side of the Yaluzangbo suture between Lhaze—Nyingchi.The channel flows originates from the first source goes to NE and NW,i.e.,to Aljin area and Karakoran area respectively.The channel flows originates from the second source goes to east,reaching to Litang—Yajiang area and North Yunnan,then diversely flows to north and south.Conclusions:The study supports the hypothesis of the Lower crust channel flows and diapiric intrusions of the flow from the Lower crust into the middle crust like dental cream,which have been resulting in break of gravitational equilibrium and uplifting of mountains in Qinghai—Xizang(Tibet) Plateau.
引文
侯遵泽,杨文采.1997.中国重力异常的小波变换与多尺度分析.地球物理学报,40(1):85~95.
侯遵泽,杨文采,刘家琦.1998.中国大陆地壳密度差异多尺度反演.地球物理学报,41(5):651~656.
李四光.1976.地质力学方法.北京:科学出版社.
孙艳云,杨文采,侯遵泽,于常青.2015.青藏高原刻痕与地壳分层构造.地质论评,61(2):269~280.
滕吉文,张中杰,白武明,等.2004.岩石圈物理学.北京:科学出版社.
肖序常,姜枚,刘训,等.2007.中国青藏高原-西北盆山岩石圈三维结构特征,北京:地质出版社.
杨文采.1987.用于位场数据处理的广义反演技术.地球物理学报,30(3):283~291.
杨文采.1997.地球物理反演的理论与方法.北京:地质出版社.
杨文采,施志群,侯遵泽,等.2001.离散小波变换与重力异常多重分解.地球物理学报,2001,44(4):534~541.
杨文采,于常青,2014a.从地壳上地幔构造看大陆碰撞作用(上).地质论评,60(2):237~259.
杨文采,于常青,2014b.从地壳上地幔构造看大陆碰撞作用(下).地质论评,60(3):486~502.
杨文采,孙艳云,于常青,侯遵泽.2015a.重力场多尺度刻痕分析与满加尔坳陷深层构造.地质学报,89(2):211~221.
杨文采,侯遵泽,孙艳云,等.2015b.用于区域重力场定量解释的多尺度刻痕分析方法.地球物理学报,58(2):520~531.
杨文采,侯遵泽,于常青.2015c.青藏高原地壳的三维密度结构和物质运动.地球物理学报,58(11):4223~4234.
杨文采,孙艳云,于常青.2015d.青藏高原地壳密度变形带及构造分区.地球物理学报,58(11):4115~4128.
杨文采.2016a.揭开南岭地壳形成演化之谜.地质论评,62(2):257~266.
杨文采.2016b.中国深埋沉积盆地和潜在储层分布的预测.地质论评,62(4):793~794.
杨文采.谢学锦.2017.西藏地球化学填图及其意义.地质论评,63(2):269~279.
Beaumont C,Jamieson R A,Nguyen M H,et al.2004.Crustal channel flows:1.Numerical models with application to the tectonics of the Himalayan Tibetan orogen.J.Geophys.Res.,109(B6):B06406,doi:10.1029/2003JB002809.
Clark M K,Royden L H.2000.Topographic ooze:eastern margin of Tibet by Lower crustal flow.Geology,28(8):703~706.
Flesch L M,Haines A J,Holt W E.2001.Dynamics of the IndiaEurasia collision zone.J.Geophys.Res.,106(B8):16435~16460.
Grujic D.2006.Channel flow and continental collision tectonics:an overview.Geol.Soc.London,268:25~37.
Harris N.2007.Channel flow and the Himalayan-Tibetan orogen:a critical review.Geol Soc London,164:511~523.
Hou Zunze,Yang Wencai.1997“&”.Wavelet transform and multiscale analysis on gravity anomalies of China.Chinese J.Geophys.,40(1):85~95.
Hou Zunze,Yang Wencai,Liu Jiaqi.1998“&”.Multiscale inversion of the density contrast within the crust of china.Chinese J.Geophys.,41(5):642~651..
James D E.1989.Encyclopedia of Solid Earth Geophysics.New York:Van Nostrand Reinhold Com.
Jolivet L and Hataf H-C.2001.Geodynamics.Lisse:A.A.Balkema Pub.
Kirby S H and Kronenbegr A K.1987.Rheology of the Lithosphere:selected topics.Rev.Geophys.,25:1219~1224.
Klemperer S L.2006.Crustal flow in eastern Tibet:geophysical evidence for the physical state of Tibertan lithosphere and inferred patterns of active flow.London:Geological Society Special Pub.,268(1):39~70.
Law R D,Searle P,Godin L,2006.Channel flow,ductile extrusion and exhumation in continental collision zones.Geological Society,London,special pub.,268~272.
Lee J S(Li Siguang).1976#.Geomechanicalapproach.Beijing:Science Press.
Meissner R and Mooney W.1998.Weakness of the lower continental crust:a condition for motions.AGU Monograph 121.
Molnar P.1988.A review of geophysical constrain of the Himalaya on the deep structure of the Tibetan Plateau,the Himalaya and the Karakoram,and their tectonic implications.Royal of London Philosophical Transactions,ser.A,326:33~88.
Rogers J W.2004.Continents and Supercontinents.Oxford:Oxford Univ.Press.
Royden L H,Clark B,King R W,et al.1997.Surface deformation and Lower crustal flow in eastern Tibet.Science,276(5313):788~790.
Schoenbohm L M,Burchfiel B C,Chen L.2006.Propagation of surface uplift,Lower crustal flow,and Cenozoic tectonics of the southeast margin of the Tibetan Plateau.Geology,34(10):813~816.
Sun Yanyun,Yang Wencai,Hou Zunze,Yu Changqing.2015“&”.Deformation Scratches and Crustal Structures in Qinghai-Xizang(Tibet)Plateau.Geological Review,61(2):269~280.
Sun Yanyun,Yang Wencai,Yu Changqing.2015.Multi-Scale Scratch Analysis in Qinghai-Tibet Plateau and its Geological Implications.Pure&applied Geophys.,172(8):2083~2332.
Sun Yanyun,Yang Wencai.2016a.Discovering crustal deformation bands by processing regional gravity field.Acta Geologica Sinica(English Edition),90(1):66~74.
Sun Yanyun,Yang Wencai,Hou Zunze,Yu Changqing.2016b.The crustal density structures and deformation scratches in QinghaiTibet Plateau.Journal of Applied Geophysics,135:32~42.
Teng Jiwen,Zhang Zhongjie,Bai Wuming,et al.2004#.Lithospheric Physics.Beijing:Science Press.
Turcotte D L,Schubert G.1982.Geodynamics.New York:John Willy&Sons:150~195.
Unsworth M,Jones A J,Wei W,et al.2005.Crustal rheology of the Himalaya and Southern Tibet inferred from magnetotelluric data.Nature,4383,doi:10:78~81.
Wang C Y,Han W B,Wu J P,et al.2007.Crustal structure beneath the eastern margin of the Tibetan Plateau and its tectonic implications.JGR,112(B7):B07307,doi:10.1029/2005JB003873.
Xiao Xuchang,Jiang Mei,Liu Xun,et al..2007“&”.The threedimensional structure of lithosphere and its evolution in western part of China.Beijing:Geological Publishing House.
Yang Wencai.1987“&”.A generalized inversion technique for potential field data processing.Chinese J.Geophys.,30(3):283~291.
Yang Wencai.1997#.Geophysical Inverse Theory and Method.Beijing:Geological Publishing House.
Yang Wencai,Shi Zhiqun,Hou Zunze,Cheng Zhengyan.2001“&”.Discrete wavelet transform for multiple decomposition of gravity anomalies.Chinese J.Geophys.,44(4):534~541.
Yang Wencai,Yu Changqing.2014a“&”.Continental collision process reveled by worldwide comparison of crust and upper mantle structures(I),Geological Review,60(2):237~259.
Yang Wencai,Yu Changqing.2014b“&”.Continental collision process reveled by worldwide comparison of crust and upper mantle structures(II),Geological Review,60(3):486~502.
Yang Wencai,Sun Yanyun,Yu Changqing,Hou Zunze.2015a“&”.Multi-scale scratch analysis of gravity field and deep structures in Manjar depression.Acta Geologica Sinica,89(2):211~221.
Yang Wencai,Sun Yanyun,Hou Zunze et al.2015b“&”.A multiscale scratch analysis method for quantitative interpretation of regional gravity fields.Chinese Journal Geophysics,58(2):520~531;doi:10.6038/cjg20150215.
Yang Wencai,Hou Zunze,Yu Changqing.2015c“&”.Threedimensional density structure of the Tibetan plateau and crustal mass movement.Chinese Journal Geophysics,58(11):4223~4234;doi:10.6038/cjg20151128.
Yang Wencai,Sun Yanyun,Yu Changqing.2015d“&”.Crustal density deformation zones of Qinghai-Tibet Plateau and their geological implications.Chinese Journal Geophysics,58(11):4115~4128;doi:10.6038/cjg20151119.
Yang Wencai.2016a&.Raise the curtain on formation and evolution of Nanling Mountains.Geological Review,62(2):257~266.
Yang Wencai.2016b&.Prediction for distribution of the deep buried sedimentary basins and potential reservoirs in China.Geological Review,62(4):793~794.
Yang Wencai,Sun Yanyun.2016a.Discovering crustal deformation bands by processing regional gravity field.Acta Geologica Sinica(English Edition),90(1):66~74.
Yang Wencai,Chen Zhaoxi,Hou Zunze.2016b.Three dimensional crustal density structure of central Asia and its geological implications.Acta Geophysica,64,DOI:1515/acgeo-2015-0056.
Yang Wencai,Xie Xuejin.2017“&”.Geochemical mapping in Xizang(Tibet)and its Significances.Geological Review,63(2):269~279.
侯遵泽,杨文采,刘家琦.1998.中国大陆地壳密度差异多尺度反演.地球物理学报,41(5):651~656.
李四光.1976.地质力学方法.北京:科学出版社.
孙艳云,杨文采,侯遵泽,于常青.2015.青藏高原刻痕与地壳分层构造.地质论评,61(2):269~280.
滕吉文,张中杰,白武明,等.2004.岩石圈物理学.北京:科学出版社.
肖序常,姜枚,刘训,等.2007.中国青藏高原-西北盆山岩石圈三维结构特征,北京:地质出版社.
杨文采.1987.用于位场数据处理的广义反演技术.地球物理学报,30(3):283~291.
杨文采.1997.地球物理反演的理论与方法.北京:地质出版社.
杨文采,施志群,侯遵泽,等.2001.离散小波变换与重力异常多重分解.地球物理学报,2001,44(4):534~541.
杨文采,于常青,2014a.从地壳上地幔构造看大陆碰撞作用(上).地质论评,60(2):237~259.
杨文采,于常青,2014b.从地壳上地幔构造看大陆碰撞作用(下).地质论评,60(3):486~502.
杨文采,孙艳云,于常青,侯遵泽.2015a.重力场多尺度刻痕分析与满加尔坳陷深层构造.地质学报,89(2):211~221.
杨文采,侯遵泽,孙艳云,等.2015b.用于区域重力场定量解释的多尺度刻痕分析方法.地球物理学报,58(2):520~531.
杨文采,侯遵泽,于常青.2015c.青藏高原地壳的三维密度结构和物质运动.地球物理学报,58(11):4223~4234.
杨文采,孙艳云,于常青.2015d.青藏高原地壳密度变形带及构造分区.地球物理学报,58(11):4115~4128.
杨文采.2016a.揭开南岭地壳形成演化之谜.地质论评,62(2):257~266.
杨文采.2016b.中国深埋沉积盆地和潜在储层分布的预测.地质论评,62(4):793~794.
杨文采.谢学锦.2017.西藏地球化学填图及其意义.地质论评,63(2):269~279.
Beaumont C,Jamieson R A,Nguyen M H,et al.2004.Crustal channel flows:1.Numerical models with application to the tectonics of the Himalayan Tibetan orogen.J.Geophys.Res.,109(B6):B06406,doi:10.1029/2003JB002809.
Clark M K,Royden L H.2000.Topographic ooze:eastern margin of Tibet by Lower crustal flow.Geology,28(8):703~706.
Flesch L M,Haines A J,Holt W E.2001.Dynamics of the IndiaEurasia collision zone.J.Geophys.Res.,106(B8):16435~16460.
Grujic D.2006.Channel flow and continental collision tectonics:an overview.Geol.Soc.London,268:25~37.
Harris N.2007.Channel flow and the Himalayan-Tibetan orogen:a critical review.Geol Soc London,164:511~523.
Hou Zunze,Yang Wencai.1997“&”.Wavelet transform and multiscale analysis on gravity anomalies of China.Chinese J.Geophys.,40(1):85~95.
Hou Zunze,Yang Wencai,Liu Jiaqi.1998“&”.Multiscale inversion of the density contrast within the crust of china.Chinese J.Geophys.,41(5):642~651..
James D E.1989.Encyclopedia of Solid Earth Geophysics.New York:Van Nostrand Reinhold Com.
Jolivet L and Hataf H-C.2001.Geodynamics.Lisse:A.A.Balkema Pub.
Kirby S H and Kronenbegr A K.1987.Rheology of the Lithosphere:selected topics.Rev.Geophys.,25:1219~1224.
Klemperer S L.2006.Crustal flow in eastern Tibet:geophysical evidence for the physical state of Tibertan lithosphere and inferred patterns of active flow.London:Geological Society Special Pub.,268(1):39~70.
Law R D,Searle P,Godin L,2006.Channel flow,ductile extrusion and exhumation in continental collision zones.Geological Society,London,special pub.,268~272.
Lee J S(Li Siguang).1976#.Geomechanicalapproach.Beijing:Science Press.
Meissner R and Mooney W.1998.Weakness of the lower continental crust:a condition for motions.AGU Monograph 121.
Molnar P.1988.A review of geophysical constrain of the Himalaya on the deep structure of the Tibetan Plateau,the Himalaya and the Karakoram,and their tectonic implications.Royal of London Philosophical Transactions,ser.A,326:33~88.
Rogers J W.2004.Continents and Supercontinents.Oxford:Oxford Univ.Press.
Royden L H,Clark B,King R W,et al.1997.Surface deformation and Lower crustal flow in eastern Tibet.Science,276(5313):788~790.
Schoenbohm L M,Burchfiel B C,Chen L.2006.Propagation of surface uplift,Lower crustal flow,and Cenozoic tectonics of the southeast margin of the Tibetan Plateau.Geology,34(10):813~816.
Sun Yanyun,Yang Wencai,Hou Zunze,Yu Changqing.2015“&”.Deformation Scratches and Crustal Structures in Qinghai-Xizang(Tibet)Plateau.Geological Review,61(2):269~280.
Sun Yanyun,Yang Wencai,Yu Changqing.2015.Multi-Scale Scratch Analysis in Qinghai-Tibet Plateau and its Geological Implications.Pure&applied Geophys.,172(8):2083~2332.
Sun Yanyun,Yang Wencai.2016a.Discovering crustal deformation bands by processing regional gravity field.Acta Geologica Sinica(English Edition),90(1):66~74.
Sun Yanyun,Yang Wencai,Hou Zunze,Yu Changqing.2016b.The crustal density structures and deformation scratches in QinghaiTibet Plateau.Journal of Applied Geophysics,135:32~42.
Teng Jiwen,Zhang Zhongjie,Bai Wuming,et al.2004#.Lithospheric Physics.Beijing:Science Press.
Turcotte D L,Schubert G.1982.Geodynamics.New York:John Willy&Sons:150~195.
Unsworth M,Jones A J,Wei W,et al.2005.Crustal rheology of the Himalaya and Southern Tibet inferred from magnetotelluric data.Nature,4383,doi:10:78~81.
Wang C Y,Han W B,Wu J P,et al.2007.Crustal structure beneath the eastern margin of the Tibetan Plateau and its tectonic implications.JGR,112(B7):B07307,doi:10.1029/2005JB003873.
Xiao Xuchang,Jiang Mei,Liu Xun,et al..2007“&”.The threedimensional structure of lithosphere and its evolution in western part of China.Beijing:Geological Publishing House.
Yang Wencai.1987“&”.A generalized inversion technique for potential field data processing.Chinese J.Geophys.,30(3):283~291.
Yang Wencai.1997#.Geophysical Inverse Theory and Method.Beijing:Geological Publishing House.
Yang Wencai,Shi Zhiqun,Hou Zunze,Cheng Zhengyan.2001“&”.Discrete wavelet transform for multiple decomposition of gravity anomalies.Chinese J.Geophys.,44(4):534~541.
Yang Wencai,Yu Changqing.2014a“&”.Continental collision process reveled by worldwide comparison of crust and upper mantle structures(I),Geological Review,60(2):237~259.
Yang Wencai,Yu Changqing.2014b“&”.Continental collision process reveled by worldwide comparison of crust and upper mantle structures(II),Geological Review,60(3):486~502.
Yang Wencai,Sun Yanyun,Yu Changqing,Hou Zunze.2015a“&”.Multi-scale scratch analysis of gravity field and deep structures in Manjar depression.Acta Geologica Sinica,89(2):211~221.
Yang Wencai,Sun Yanyun,Hou Zunze et al.2015b“&”.A multiscale scratch analysis method for quantitative interpretation of regional gravity fields.Chinese Journal Geophysics,58(2):520~531;doi:10.6038/cjg20150215.
Yang Wencai,Hou Zunze,Yu Changqing.2015c“&”.Threedimensional density structure of the Tibetan plateau and crustal mass movement.Chinese Journal Geophysics,58(11):4223~4234;doi:10.6038/cjg20151128.
Yang Wencai,Sun Yanyun,Yu Changqing.2015d“&”.Crustal density deformation zones of Qinghai-Tibet Plateau and their geological implications.Chinese Journal Geophysics,58(11):4115~4128;doi:10.6038/cjg20151119.
Yang Wencai.2016a&.Raise the curtain on formation and evolution of Nanling Mountains.Geological Review,62(2):257~266.
Yang Wencai.2016b&.Prediction for distribution of the deep buried sedimentary basins and potential reservoirs in China.Geological Review,62(4):793~794.
Yang Wencai,Sun Yanyun.2016a.Discovering crustal deformation bands by processing regional gravity field.Acta Geologica Sinica(English Edition),90(1):66~74.
Yang Wencai,Chen Zhaoxi,Hou Zunze.2016b.Three dimensional crustal density structure of central Asia and its geological implications.Acta Geophysica,64,DOI:1515/acgeo-2015-0056.
Yang Wencai,Xie Xuejin.2017“&”.Geochemical mapping in Xizang(Tibet)and its Significances.Geological Review,63(2):269~279.