塔里木西南缘下地壳低速层的成因:斜长角闪岩的纵波速度和衰减的限制
|
摘要
在1 0GPa,室温～1200℃条件下,测量了新疆库地地区斜长角闪岩的纵波速度(Vp)和品质因子(Q值),得出在1 0GPa恒压下,Vp和Q值随温度和深度的变化关系。结果显示,Vp和Q值随温度的升高而下降,观察实验样品并结合Vp和Q值与熔体含量的关系,发现部分熔融是影响Vp和Q值变化的主要因素。依据实验结果,并结合区域上压力梯度和温度梯度资料计算了Vp和Q值随深度的变化。结果表明Vp和Q值先随深度的增加而缓慢增大,在32km左右开始突然减小,表明开始出现低速层。结合温度和熔体含量的关系得出,低速层的出现可能是部分熔融的结果。塔里木及周边地区的地震测深以及地震反演的结果也显示,在相同的温度和压力条件下,地壳内部32～44km的范围内存在低速层,同时高温高压的实验结果与阿拉木图地区的Vp值相当一致,可以推测塔里木西南缘下地壳的岩石成分中含有斜长角闪岩。
Compressional wave velocity (Vp) and attenuation (Q) in amphibolite collected from Kudi, Xinjiang, were measured at high pressure (10 GPa) and high temperature (up to 1200℃) The experimental results showed that Vp and Q values decrease with increasing temperature, reflecting that Vp and Q are influenced by partial melting The relationship of Vp and Q with depth, in the light of the correlations between Vp and Q and temperature and pressure, shows that Vp and Q increase with depth The tendency of increasing is the same as that obtained by seismological studies The lowvelocity layer appears at the depth of 32km, at which the Vp and Q decrease rapidly Seismic study in Tarim and its vicinity yielded the same result The lowvelocity layer is measured from 32km to 44km in the Kuytun, Tianshan and Alamtu areas So it may be concluded that amphibolite probably exits in the lower crust of Southwest Tarim And partial melting is the main reason for the existence of the lowervelocity layer
Compressional wave velocity (Vp) and attenuation (Q) in amphibolite collected from Kudi, Xinjiang, were measured at high pressure (10 GPa) and high temperature (up to 1200℃) The experimental results showed that Vp and Q values decrease with increasing temperature, reflecting that Vp and Q are influenced by partial melting The relationship of Vp and Q with depth, in the light of the correlations between Vp and Q and temperature and pressure, shows that Vp and Q increase with depth The tendency of increasing is the same as that obtained by seismological studies The lowvelocity layer appears at the depth of 32km, at which the Vp and Q decrease rapidly Seismic study in Tarim and its vicinity yielded the same result The lowvelocity layer is measured from 32km to 44km in the Kuytun, Tianshan and Alamtu areas So it may be concluded that amphibolite probably exits in the lower crust of Southwest Tarim And partial melting is the main reason for the existence of the lowervelocity layer
引文
[1]MuraseT,KushiroI Compressionalwavevelocityinpartiallymoltenperidotiteathighpressure[J] CarnegieInst Wash YB ,1979,78:559～562
[2]周文戈,谢鸿森,赵志丹,等.高压下粗面玄武岩相变对其纵波速度影响的研究[J].科学通报,1999,44(4):424～427.
[3]赵志丹,高山,骆庭川,等.秦岭和华北地区地壳低速层的成因探讨———岩石高温高压波速实验证据[J].地球物理学报,1996,39:239～259.
[4]张友南,马谨.深部地壳镁铁质岩石波速的研究[J].地球物理学报,1997,40:221～230.
[5]刘斌,KernH,PoppT.不同围压下孔隙度不同的干燥及水饱和岩样中的纵横波速度及衰减[J].地球物理学报,1998,41(4):537～546.
[6]KimDO,KataharaKW,ManghnaniMH,etal Velocityandattenuationanisotropyindeep seacarbonatesediments[J] JournalofGeophysicalResearch,1983,88(B3):2337～2343
[7]SatoH,ManghnaniMH UtrasonicmeasurementsofVpandQp:relaxationspectrumofcomplexmodulusonbasaltmelts[J]Phys Earthplanet Inter ,1985,41:18～33
[8]胥颐,冯先岳,BH萨茨洛夫.天山地区的深部速度结构[J].地震地质,1996,18(4):375～381.
[9]胥颐.天山地震活动区的深部结构特征[J].地震地质,1996,14(2):135～142.
[10]卢德源,李秋生,高锐,等.横跨天山的人工爆炸地震剖面[J].科学通报,2000,45(9):982～988.
[11]马宗晋,赵俊猛.天山与阴山—燕山造山带的深部结构和地震[J].地学前缘,1999,6(3):95～102.
[12]谢鸿森,张月明,徐惠刚,等.高温超高压下测量岩石矿物弹性波速的新方法及其地学意义[J].中国科学(B辑),1993,23(8):861～864.
[13]JohnstonDH,ToksozMN Thermalcrackingandamplitudedependentattenuation[J] J Geophys Res ,1980,85(B2):937～942
[14]KernH,LiuB,PoppT RelationshipbetweenanisotropyofPandSwavevelocitiesandanisotropyofattenuationinserpentiniteandamphibolite[J] J Geophys Res ,1997,102(B2):3051～3065
[15]JohnstonDH,ToksozMN UltrasonicPandSwaveattenuationindryandsaturatedrocksunderpressure[J] JournalofGeophysicalResearch,1980,85(B2):925～936
[16]MatsushimaS Compressionalandshearwavevelocitiesofigneousrocksandvolcanicglassesto900℃and20kbar[J] Tectonophysics,1981,75:257～271
[17]谢鸿森,周文戈,李玉文,等.高温高压下蛇纹岩脱水的弹性特征及其意义[J].地球物理学报,2000,43(6):806～811.
[18]母润昌,高平,刘若新,等.华北地区韧性剪切带几种岩石的波速各向异性高温高压实验研究[J].地球物理学报,1995,38:213～220.
[19]KernH,BurliniL AschchepkovIV Fabric relatedseismicanisotropyinupper mantlexenoliths:evidencefrommeasurementsandcalculations[J] PhysicsoftheEarthandPlanteryInteriors,1996,95:195～209
[20]刘斌.不同温压下岩石弹性波速度、衰减及各向异性与组构的关系[J].地学前缘,2000,7(1):247～257.
[21]赵志丹,谢鸿森,周文戈,等.大别山榴辉岩的密度和波速及其对壳———幔循环的启示[J].矿物岩石地球化学通报,2001,20(1):6～10.
[22]BiotMA Mechanicsofdeformationandacousticpropagationinporousmedia[J] J Appl Phys ,1962,33(4):1482～1498
[23]MavkoGM,NurA Waveattenuationinpartiallysaturatedrocks[J] Geophysics,1979,44(1):161～178
[24]YamakawaN Scatteringandattenuationofelasticwaves[J] Geophys Mag ,1962,31(1):61～103
[25]刘斌,葛宁洁,KernH,等.不同温压条件下蛇纹岩和角闪岩中波速和衰减的各向异性[J].地球物理学报,1998,41(3):371～381.
[26]刘永祥,伍旭光.高温高压下岩石波速与地壳深部的物质组成[J].地球物理学报,1997,40(2):211～220.
[27]范善发,周中毅,解启东.深部碳酸盐岩油气生成和保存的特征及其模拟实验研究[J].沉积学报,1997,15(2):114～117.
[28]王社教,胡圣标,汪集.塔里木盆地沉积层放射性生热的热效应及其意义[J].石油勘探与开发,1999,26(5):36～39.
[29]潘长春,周中毅,范善发,等.塔里木盆地热历史[J].矿物岩石地球化学通报,1996,15(3):150～177.
[30]任战利.中国北方沉积盆地热演化史的对比[J].石油与天然气地质,2000,21(1):33～37.
[31]邵济安,韩庆军.内蒙古东部早中生代壳幔过渡带———捕虏体岩石高温高压弹性波速度实验证据[J].中国科学(D辑),2000,30(增刊):154～160.
[32]周民都,张元生,李清河,等.天水地震区Q值结构[J].地球物理学报,1996,39:216～223.
[33]HartmutKern,ShanGao,Qing ShenLiu SeismicpropertiesanddensitiesofmiddleandlowercrustalrocksexposedalongtheNorthChinaGeoscienceTransect[J] EarthandPlanetaryScienceLetters,1996,139:439～455
[34]YoshitakaAizawa,KazuhikoIto,YoshiyukiTatsumi Compressionalwavevelocityofgraniteandamphiboliteuptomeltingtemperaturesat1Gpa[J] Tectonophysics,2002,351:255～261
[35]顾芷娟,郭才华,李彪,等.壳内低速高导层成因初步探讨[J].中国科学(B辑),1995,25(1):108～113.
[2]周文戈,谢鸿森,赵志丹,等.高压下粗面玄武岩相变对其纵波速度影响的研究[J].科学通报,1999,44(4):424～427.
[3]赵志丹,高山,骆庭川,等.秦岭和华北地区地壳低速层的成因探讨———岩石高温高压波速实验证据[J].地球物理学报,1996,39:239～259.
[4]张友南,马谨.深部地壳镁铁质岩石波速的研究[J].地球物理学报,1997,40:221～230.
[5]刘斌,KernH,PoppT.不同围压下孔隙度不同的干燥及水饱和岩样中的纵横波速度及衰减[J].地球物理学报,1998,41(4):537～546.
[6]KimDO,KataharaKW,ManghnaniMH,etal Velocityandattenuationanisotropyindeep seacarbonatesediments[J] JournalofGeophysicalResearch,1983,88(B3):2337～2343
[7]SatoH,ManghnaniMH UtrasonicmeasurementsofVpandQp:relaxationspectrumofcomplexmodulusonbasaltmelts[J]Phys Earthplanet Inter ,1985,41:18～33
[8]胥颐,冯先岳,BH萨茨洛夫.天山地区的深部速度结构[J].地震地质,1996,18(4):375～381.
[9]胥颐.天山地震活动区的深部结构特征[J].地震地质,1996,14(2):135～142.
[10]卢德源,李秋生,高锐,等.横跨天山的人工爆炸地震剖面[J].科学通报,2000,45(9):982～988.
[11]马宗晋,赵俊猛.天山与阴山—燕山造山带的深部结构和地震[J].地学前缘,1999,6(3):95～102.
[12]谢鸿森,张月明,徐惠刚,等.高温超高压下测量岩石矿物弹性波速的新方法及其地学意义[J].中国科学(B辑),1993,23(8):861～864.
[13]JohnstonDH,ToksozMN Thermalcrackingandamplitudedependentattenuation[J] J Geophys Res ,1980,85(B2):937～942
[14]KernH,LiuB,PoppT RelationshipbetweenanisotropyofPandSwavevelocitiesandanisotropyofattenuationinserpentiniteandamphibolite[J] J Geophys Res ,1997,102(B2):3051～3065
[15]JohnstonDH,ToksozMN UltrasonicPandSwaveattenuationindryandsaturatedrocksunderpressure[J] JournalofGeophysicalResearch,1980,85(B2):925～936
[16]MatsushimaS Compressionalandshearwavevelocitiesofigneousrocksandvolcanicglassesto900℃and20kbar[J] Tectonophysics,1981,75:257～271
[17]谢鸿森,周文戈,李玉文,等.高温高压下蛇纹岩脱水的弹性特征及其意义[J].地球物理学报,2000,43(6):806～811.
[18]母润昌,高平,刘若新,等.华北地区韧性剪切带几种岩石的波速各向异性高温高压实验研究[J].地球物理学报,1995,38:213～220.
[19]KernH,BurliniL AschchepkovIV Fabric relatedseismicanisotropyinupper mantlexenoliths:evidencefrommeasurementsandcalculations[J] PhysicsoftheEarthandPlanteryInteriors,1996,95:195～209
[20]刘斌.不同温压下岩石弹性波速度、衰减及各向异性与组构的关系[J].地学前缘,2000,7(1):247～257.
[21]赵志丹,谢鸿森,周文戈,等.大别山榴辉岩的密度和波速及其对壳———幔循环的启示[J].矿物岩石地球化学通报,2001,20(1):6～10.
[22]BiotMA Mechanicsofdeformationandacousticpropagationinporousmedia[J] J Appl Phys ,1962,33(4):1482～1498
[23]MavkoGM,NurA Waveattenuationinpartiallysaturatedrocks[J] Geophysics,1979,44(1):161～178
[24]YamakawaN Scatteringandattenuationofelasticwaves[J] Geophys Mag ,1962,31(1):61～103
[25]刘斌,葛宁洁,KernH,等.不同温压条件下蛇纹岩和角闪岩中波速和衰减的各向异性[J].地球物理学报,1998,41(3):371～381.
[26]刘永祥,伍旭光.高温高压下岩石波速与地壳深部的物质组成[J].地球物理学报,1997,40(2):211～220.
[27]范善发,周中毅,解启东.深部碳酸盐岩油气生成和保存的特征及其模拟实验研究[J].沉积学报,1997,15(2):114～117.
[28]王社教,胡圣标,汪集.塔里木盆地沉积层放射性生热的热效应及其意义[J].石油勘探与开发,1999,26(5):36～39.
[29]潘长春,周中毅,范善发,等.塔里木盆地热历史[J].矿物岩石地球化学通报,1996,15(3):150～177.
[30]任战利.中国北方沉积盆地热演化史的对比[J].石油与天然气地质,2000,21(1):33～37.
[31]邵济安,韩庆军.内蒙古东部早中生代壳幔过渡带———捕虏体岩石高温高压弹性波速度实验证据[J].中国科学(D辑),2000,30(增刊):154～160.
[32]周民都,张元生,李清河,等.天水地震区Q值结构[J].地球物理学报,1996,39:216～223.
[33]HartmutKern,ShanGao,Qing ShenLiu SeismicpropertiesanddensitiesofmiddleandlowercrustalrocksexposedalongtheNorthChinaGeoscienceTransect[J] EarthandPlanetaryScienceLetters,1996,139:439～455
[34]YoshitakaAizawa,KazuhikoIto,YoshiyukiTatsumi Compressionalwavevelocityofgraniteandamphiboliteuptomeltingtemperaturesat1Gpa[J] Tectonophysics,2002,351:255～261
[35]顾芷娟,郭才华,李彪,等.壳内低速高导层成因初步探讨[J].中国科学(B辑),1995,25(1):108～113.
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