藏南上地壳低速高导层的性质与分布:来自热水流体活动的证据
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摘要
沿亚东—谷露裂谷带实施的一系列地球物理探测发现了一组地震亮点。结合其他地球物理探测剖面的资料 ,认为藏南上地壳中存在一个低速高导层 ,这些地震亮点处于这个低速高导层中。人们对这些亮点和低速高导层有两种不同的解释和认识 :一种认为是含盐的超临界流体 ;而另一种认为是地壳中的部分熔融层。由于目前缺少有效的手段和方法 ,对这个低速高导层的性质和分布范围仍只是推测。本文从藏南强烈活动的热水流体系统着手 ,尝试从另一个角度探讨这些地震亮点和低速高导层的性质。通过对热泉气体的 He同位素组成和热水的地球化学特征研究以及前人对温度场的模拟表明 ,该低速高导层的性质为硅酸盐岩浆熔体 ,不是以水为主的流体 ,这就为部分熔融层的存在提供了佐证。本文进一步讨论了该部分熔融层对热泉流体系统的驱动热机作用 ,并根据热泉流体的温度场限定了此部分熔融层的空间分布范围。
During the process for carrying out of a series of geophysical probe, a suit of were observed along the Yadong—Gulou rift valley zone. Combining with data from other geophysical sections, a low velocity-high conductivity layer was recognized in the upper crust in the southern Tibet. These seismic bright spots do lie in the low velocity-high conductivity layer. For these bright spots and the low velocity-high conductivity layer, there are still two kinds of understandings and opinions: one is saliferous supercritical fluid; the other is partial melting layer of the upper crust. Due to lack of effective means and methods, their characteristic and distribution were still guessed. Based on the research on the violent hydrothermal activity of the south Tibet, this paper made an attempt to discuss the characteristic of these bright spots and low velocity-high conductivity layer from other point. The research on helium isotope composition of hot spring's gas, geochemical characteristic of spring water, and former modeling for temperature field suggest that the low velocity-high conductivity layer was composed of rather silicate magma than water fluid. Theses research provide new evidences for exist of the partial melting layers. What's more, this paper discusses how the partial melting layer driving the active hydrothermal system to circulate and flow, At last, and restrict the spatial distribution of the partial melting layer based on the distribution of hot springs and temperature field.
During the process for carrying out of a series of geophysical probe, a suit of were observed along the Yadong—Gulou rift valley zone. Combining with data from other geophysical sections, a low velocity-high conductivity layer was recognized in the upper crust in the southern Tibet. These seismic bright spots do lie in the low velocity-high conductivity layer. For these bright spots and the low velocity-high conductivity layer, there are still two kinds of understandings and opinions: one is saliferous supercritical fluid; the other is partial melting layer of the upper crust. Due to lack of effective means and methods, their characteristic and distribution were still guessed. Based on the research on the violent hydrothermal activity of the south Tibet, this paper made an attempt to discuss the characteristic of these bright spots and low velocity-high conductivity layer from other point. The research on helium isotope composition of hot spring's gas, geochemical characteristic of spring water, and former modeling for temperature field suggest that the low velocity-high conductivity layer was composed of rather silicate magma than water fluid. Theses research provide new evidences for exist of the partial melting layers. What's more, this paper discusses how the partial melting layer driving the active hydrothermal system to circulate and flow, At last, and restrict the spatial distribution of the partial melting layer based on the distribution of hot springs and temperature field.
引文
陈炳蔚,任留东,王彦斌.2000.青藏高原及邻区大地构造及有关的变形特征.见:肖序常,李廷栋主编.青藏高原的构造演化与隆升机制.广州:广东科技出版社,85～122.
侯增谦,莫宣学,高永丰,曲晓明.2003.埃达克岩:斑岩铜矿的重要含矿母岩——以西藏和智利斑岩铜矿为例.矿床地质,21:1～12.
侯增谦,李振清,曲晓明,等.2001.0.5Ma以来的青藏高原隆升过程——来自冈底斯带热水活动的证据.中国科学(D辑),31(增刊):27～33.
侯增谦,李振清.2004.印度大陆俯冲前缘的可能位置:来自藏南和藏东活动热泉气体He同位素约束.地质学报,78(4):482～493.
李海兵,戚学祥,朱迎堂,杨经绥,PaulTAPPONNIER,史连昌,王永文.2004.青藏高原内部物质向东滑移的证据.地质学报,78(5):633～640.
李秋生,彭苏萍,高锐.2004.青藏高原莫霍面的研究进展.地质论评,50(6):598～613.
李振清.2002.青藏高原碰撞造山过程中的现代热水活动.中国地质科学院博士论文.
潘裕生,孔祥儒,钟大赉,等.1998.青藏高原岩石圈结构、演化和动力学.见:孙鸿烈等主编.青藏高原形成演化与发展.广州:广东科技出版社,1～65.
曲晓明,侯增谦,国连杰,徐文艺.2004.冈底斯铜矿带埃达克质含矿斑岩的源区组成与地壳混染:Nd、Sr、Pb、O同位素约束.地质学报,78(6):813～821.
沈显杰,张文仁,杨淑贞,等.1990.青藏热流与地体构造热演化.北京:地质出版社,1～90.
佟伟,张铭陶,张之非,等.1981.西藏地热.北京:科学出版社.王绳祖.2004.青藏高原地震断裂共轭角分布特征及其大陆动力学意义.地质学报,78(4):475～481.
夏报本,张家诚.1993.西藏地热活动规律初探.见:中国西藏高温地热开发利用国际研讨会论文选.北京:地质出版社,1～7.
袁道阳,张培震,刘百篪,甘卫军,毛凤英,王志才,郑文俊,郭华.2004.青藏高原东北缘晚第四纪活动构造的几何图像与构造转换.地质学报,78(2):270～278.
张进,马宗晋.2004.西藏高原西、中、东的分段性及其意义.地质学报,78(2):218～227.
张理刚.1985.稳定同位素在地质科学中的应用.西安:陕西科学技术出版社.
张知非,朱梅湘,刘时彬.1982.西藏水热地球化学的初步研究.北京大学学报,(3):88～96.
赵平,金建,张海政,等.1998.西藏羊八井地热田热水的化学组成.地质科学,33(1):61～72.
赵文津,纳尔逊,车敬凯,等.1996.喜马拉雅地区深反射地震——揭示印度大陆北缘岩石圈的复杂结构.地球学报,17(2):138～152.
赵文津,吴珍汉.2004.加强地表层与深层调查的结合,深化对中国大地构造特征的认识.地质论评,50(3):256～267.
朱炳球,朱立新,史长义,等.1992.地热田地球化学勘查.北京:科学出版社.
AndrewsJN.1985.The isotopic composition of radiogenic helium andits use to study groundwater movement in confined aquifers.Chem.Geology,49:339～350.
BllsnlukP M,HackerB,GlodnyJ,RatschbacherL ,BillS,WuZ H,McWilliamsM O,CalvertA.2001.Normal faulting in centralTibet since at least13.5Myr ago.Nature,412:628～632.
BrownL D,ZhaoW J,NelsonK D,et al.1996.Bright spots,structure,and magmatism in southernTibet fromINDEPTHserimic reflection profiling.Science,274:1688～1690.
ChenBingwei,RenLiudong,WangYanbin.2000. the geotectonicand deformation characteristic for theQinghai—Xizang plateauand adjacent areas.In:XiaoXuchang,L iTingdong ads.Tectonic evolution and uplifting mechanism of theQinghai—Xizang plateau.Guangzhou:Guangdong science and technologypress,85～122.
ColemanM,HodgesK.1995.Evidence forTibetan plateau upliftbefore14Myr ago from a new minimum age for east-westextension.Nature,374:49～52.
DingL ,ZhongD L ,YinA,HarrisonT M.2001.Cenozoic structuraland metamorphic evolution of the easternHimalayan syntaxis(NamcheBarwa).EarthPlanet.Sci.Lett.,192:423～438.
HokeL ,LambS,HiltonD,PoredaR J.2000.Southern limit ofmantle-derived geothermal helium emissions inTibet:implicationsfor lithoshperic structure.EarthPlanet.Sci.L ett.,180:297～308.
HouZengqian,L iZhenqing,QuXiaoming et al.2001.The upliftingprocesses of the tibetan plateau since0.5MaB.P.:evidencesfrom hydrothermal activity in theGangdise belt.Science inChina(SeriesD),44(sup.):35～44.
HouZengqian,L iZhenqing.2004.Possible location forunderthrusting front of theIndus continent:constrains fromhelium isotope of the geothermal gas in southernTibetand easternTibet.Acta geologica sinica,78(4):482～493.
HouZengqian,MoXuanxue,GaoYongfeng et al.2003 c.Adakite,apossible host rock porphyry copper deposits:case studies ofporphyry copper belts inTibetan plateau and in northernChile.Mineral deposits,22(1):1～12.
KimmelmannE S.1996.Use ofHelium isotopes in groundwaterstudies of theParanaBasin,Brasil.In:30 th internationalgeological congress abstracts.3(3):238.
KindR,NiJ,ZhaoW,et al.1996.Evidence from earthquake datafor a partially molten crustal layer in southernTibet.Science,274:1692～1694.
L iZhenqing.2002.The modern hydrothermal fluid activity during thecollisional orogenesis in theTibetan plateau.Ph.D.thesis.
MakovskyY,KlempererS L.1999.Measuring the seismic propertiesofTibetan bright spots:evidence for free aqueous fluids in theTibetan middle crust.J.Geophys.Res.,104:10795～10825.
MolnarP,TapponnierP.1978.Active tectonics ofTibet.JGeophysRes,83:5361～5375.
NelsonK D,ZhaoW J,BrownL D,et al.1996.Parially moltenmiddle crust beneathSouthernTibet:synthesis of projectINDEPTH results.Science,274:1684～1688.
NiJ,YorkJ.1978.L ateCenozoic tectonics of theTibetan plateau.JGeophysRes,83:5377～5384.
PanYusheng,KongXiangru,ZhongDalai,et al.1998.Structure,evolution and kinetics of the lithosphere in theQinghai—Xizangplateau.In:SunHonglie andZhengDu ads.Formation,evolution and development of theQinghai—Xiang plateau.Guangzhou:Guangdong science and technology press,1～65.
ShenXianjie,ZhangWenren,YangShuzhen,et al.1990.Heat flowand heat evolvement of terrain tectonic inQinghai—Xizangplateau.,1～90.
TapponnierP,MolnarP.1977.Active faulting and tectonics ofChina.J.Geophys.Res.,82:2905～2930.
TongWei,ZhangMingtao,ZhangZhifei,etal.1981.Geothermal intheXizang plateau.Beijing:SciencePress
WeiWenbo,MartynUnsworth,AlanJones,etal.2001.Detection ofwidespread fluids in theTibetan crust by magnetotelluric studies.Science,292:716～718.
WilliamsH,TurnerS,KelleyS,HarrisN.2001.Age andcomposition of dikes inSouthernTibet:new constraints on thetiming of east-west extension and lt' s relationship to post-collisional volcanism.Geology,29:339～342.
XiaBaoben,ZhangJiacheng.1993.Primary research about theconvention of geothermal activity inTibet.In:collected papersofinternational proseminar on development and utilization ofmegatemperaure geothermal inTibet,China.Beijing:Geologicalpublishing house,1～7.
YinA,HarrisonT M.2000.Geologic evolution of theHimalayan—Tibetan orogen.J.Ann.Rev.EarthPlanet.Sci.,28:211～280.
YokoyamaT,NakaiS,WaikitaH.1999.Helium and carbon isotopiccompositions of hot spring gases in theTibetan plateau.J.Volcan.Geotherm.Res.,88:99～107.
ZhangLigang.1985.Application of stable isotope in geologicalscience.Xi' an:Shanxi science and technology press
ZhangZhifei,ZhuMeixiang,LiuShibin.1982.Primary researchabout hydrothermal geochemistry inTibet.Transaction of thePekingU niversity,(3):88～96.
ZhaoPing,JinJian,ZhangHaizheng,et al.1998.Chemicalcomposition of thermal water in theYangbajing geothermal field,Tibet.ChineseScienceBulletin,33(1):61～72.
ZhaoW J,NelsonK D,PojectINDEPTH team.1996.Deep seismicreflection evidence for continental underthrusting beneath thesouthTibet.Nature,366:557～559.
ZhaoWenjin,Nelson,CheJingkai,et al.1996.Deep seismicreflection inHamalaya region reveals the complexity of the crustand upper mantle.ActaGeoscientiaSinica,17(2):138～152.
ZhuBingqiu,ZhuLixin,ShiChangyi,et al.1992.Geochemicalexploration in geothermal field.Beijing:GeologicalPress.
侯增谦,莫宣学,高永丰,曲晓明.2003.埃达克岩:斑岩铜矿的重要含矿母岩——以西藏和智利斑岩铜矿为例.矿床地质,21:1～12.
侯增谦,李振清,曲晓明,等.2001.0.5Ma以来的青藏高原隆升过程——来自冈底斯带热水活动的证据.中国科学(D辑),31(增刊):27～33.
侯增谦,李振清.2004.印度大陆俯冲前缘的可能位置:来自藏南和藏东活动热泉气体He同位素约束.地质学报,78(4):482～493.
李海兵,戚学祥,朱迎堂,杨经绥,PaulTAPPONNIER,史连昌,王永文.2004.青藏高原内部物质向东滑移的证据.地质学报,78(5):633～640.
李秋生,彭苏萍,高锐.2004.青藏高原莫霍面的研究进展.地质论评,50(6):598～613.
李振清.2002.青藏高原碰撞造山过程中的现代热水活动.中国地质科学院博士论文.
潘裕生,孔祥儒,钟大赉,等.1998.青藏高原岩石圈结构、演化和动力学.见:孙鸿烈等主编.青藏高原形成演化与发展.广州:广东科技出版社,1～65.
曲晓明,侯增谦,国连杰,徐文艺.2004.冈底斯铜矿带埃达克质含矿斑岩的源区组成与地壳混染:Nd、Sr、Pb、O同位素约束.地质学报,78(6):813～821.
沈显杰,张文仁,杨淑贞,等.1990.青藏热流与地体构造热演化.北京:地质出版社,1～90.
佟伟,张铭陶,张之非,等.1981.西藏地热.北京:科学出版社.王绳祖.2004.青藏高原地震断裂共轭角分布特征及其大陆动力学意义.地质学报,78(4):475～481.
夏报本,张家诚.1993.西藏地热活动规律初探.见:中国西藏高温地热开发利用国际研讨会论文选.北京:地质出版社,1～7.
袁道阳,张培震,刘百篪,甘卫军,毛凤英,王志才,郑文俊,郭华.2004.青藏高原东北缘晚第四纪活动构造的几何图像与构造转换.地质学报,78(2):270～278.
张进,马宗晋.2004.西藏高原西、中、东的分段性及其意义.地质学报,78(2):218～227.
张理刚.1985.稳定同位素在地质科学中的应用.西安:陕西科学技术出版社.
张知非,朱梅湘,刘时彬.1982.西藏水热地球化学的初步研究.北京大学学报,(3):88～96.
赵平,金建,张海政,等.1998.西藏羊八井地热田热水的化学组成.地质科学,33(1):61～72.
赵文津,纳尔逊,车敬凯,等.1996.喜马拉雅地区深反射地震——揭示印度大陆北缘岩石圈的复杂结构.地球学报,17(2):138～152.
赵文津,吴珍汉.2004.加强地表层与深层调查的结合,深化对中国大地构造特征的认识.地质论评,50(3):256～267.
朱炳球,朱立新,史长义,等.1992.地热田地球化学勘查.北京:科学出版社.
AndrewsJN.1985.The isotopic composition of radiogenic helium andits use to study groundwater movement in confined aquifers.Chem.Geology,49:339～350.
BllsnlukP M,HackerB,GlodnyJ,RatschbacherL ,BillS,WuZ H,McWilliamsM O,CalvertA.2001.Normal faulting in centralTibet since at least13.5Myr ago.Nature,412:628～632.
BrownL D,ZhaoW J,NelsonK D,et al.1996.Bright spots,structure,and magmatism in southernTibet fromINDEPTHserimic reflection profiling.Science,274:1688～1690.
ChenBingwei,RenLiudong,WangYanbin.2000. the geotectonicand deformation characteristic for theQinghai—Xizang plateauand adjacent areas.In:XiaoXuchang,L iTingdong ads.Tectonic evolution and uplifting mechanism of theQinghai—Xizang plateau.Guangzhou:Guangdong science and technologypress,85～122.
ColemanM,HodgesK.1995.Evidence forTibetan plateau upliftbefore14Myr ago from a new minimum age for east-westextension.Nature,374:49～52.
DingL ,ZhongD L ,YinA,HarrisonT M.2001.Cenozoic structuraland metamorphic evolution of the easternHimalayan syntaxis(NamcheBarwa).EarthPlanet.Sci.Lett.,192:423～438.
HokeL ,LambS,HiltonD,PoredaR J.2000.Southern limit ofmantle-derived geothermal helium emissions inTibet:implicationsfor lithoshperic structure.EarthPlanet.Sci.L ett.,180:297～308.
HouZengqian,L iZhenqing,QuXiaoming et al.2001.The upliftingprocesses of the tibetan plateau since0.5MaB.P.:evidencesfrom hydrothermal activity in theGangdise belt.Science inChina(SeriesD),44(sup.):35～44.
HouZengqian,L iZhenqing.2004.Possible location forunderthrusting front of theIndus continent:constrains fromhelium isotope of the geothermal gas in southernTibetand easternTibet.Acta geologica sinica,78(4):482～493.
HouZengqian,MoXuanxue,GaoYongfeng et al.2003 c.Adakite,apossible host rock porphyry copper deposits:case studies ofporphyry copper belts inTibetan plateau and in northernChile.Mineral deposits,22(1):1～12.
KimmelmannE S.1996.Use ofHelium isotopes in groundwaterstudies of theParanaBasin,Brasil.In:30 th internationalgeological congress abstracts.3(3):238.
KindR,NiJ,ZhaoW,et al.1996.Evidence from earthquake datafor a partially molten crustal layer in southernTibet.Science,274:1692～1694.
L iZhenqing.2002.The modern hydrothermal fluid activity during thecollisional orogenesis in theTibetan plateau.Ph.D.thesis.
MakovskyY,KlempererS L.1999.Measuring the seismic propertiesofTibetan bright spots:evidence for free aqueous fluids in theTibetan middle crust.J.Geophys.Res.,104:10795～10825.
MolnarP,TapponnierP.1978.Active tectonics ofTibet.JGeophysRes,83:5361～5375.
NelsonK D,ZhaoW J,BrownL D,et al.1996.Parially moltenmiddle crust beneathSouthernTibet:synthesis of projectINDEPTH results.Science,274:1684～1688.
NiJ,YorkJ.1978.L ateCenozoic tectonics of theTibetan plateau.JGeophysRes,83:5377～5384.
PanYusheng,KongXiangru,ZhongDalai,et al.1998.Structure,evolution and kinetics of the lithosphere in theQinghai—Xizangplateau.In:SunHonglie andZhengDu ads.Formation,evolution and development of theQinghai—Xiang plateau.Guangzhou:Guangdong science and technology press,1～65.
ShenXianjie,ZhangWenren,YangShuzhen,et al.1990.Heat flowand heat evolvement of terrain tectonic inQinghai—Xizangplateau.,1～90.
TapponnierP,MolnarP.1977.Active faulting and tectonics ofChina.J.Geophys.Res.,82:2905～2930.
TongWei,ZhangMingtao,ZhangZhifei,etal.1981.Geothermal intheXizang plateau.Beijing:SciencePress
WeiWenbo,MartynUnsworth,AlanJones,etal.2001.Detection ofwidespread fluids in theTibetan crust by magnetotelluric studies.Science,292:716～718.
WilliamsH,TurnerS,KelleyS,HarrisN.2001.Age andcomposition of dikes inSouthernTibet:new constraints on thetiming of east-west extension and lt' s relationship to post-collisional volcanism.Geology,29:339～342.
XiaBaoben,ZhangJiacheng.1993.Primary research about theconvention of geothermal activity inTibet.In:collected papersofinternational proseminar on development and utilization ofmegatemperaure geothermal inTibet,China.Beijing:Geologicalpublishing house,1～7.
YinA,HarrisonT M.2000.Geologic evolution of theHimalayan—Tibetan orogen.J.Ann.Rev.EarthPlanet.Sci.,28:211～280.
YokoyamaT,NakaiS,WaikitaH.1999.Helium and carbon isotopiccompositions of hot spring gases in theTibetan plateau.J.Volcan.Geotherm.Res.,88:99～107.
ZhangLigang.1985.Application of stable isotope in geologicalscience.Xi' an:Shanxi science and technology press
ZhangZhifei,ZhuMeixiang,LiuShibin.1982.Primary researchabout hydrothermal geochemistry inTibet.Transaction of thePekingU niversity,(3):88～96.
ZhaoPing,JinJian,ZhangHaizheng,et al.1998.Chemicalcomposition of thermal water in theYangbajing geothermal field,Tibet.ChineseScienceBulletin,33(1):61～72.
ZhaoW J,NelsonK D,PojectINDEPTH team.1996.Deep seismicreflection evidence for continental underthrusting beneath thesouthTibet.Nature,366:557～559.
ZhaoWenjin,Nelson,CheJingkai,et al.1996.Deep seismicreflection inHamalaya region reveals the complexity of the crustand upper mantle.ActaGeoscientiaSinica,17(2):138～152.
ZhuBingqiu,ZhuLixin,ShiChangyi,et al.1992.Geochemicalexploration in geothermal field.Beijing:GeologicalPress.
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