云南峨眉山高钛和低钛玄武岩的岩石成因
摘要
峨眉山玄武岩主要的岩石类型是低钛玄武岩和高钛玄武岩,并有少量的苦橄岩。它们不同程度地富集大离子亲石元素和轻稀土元素,相对亏损重稀土元素,稀土元素分馏明显或比较明显,相容元素(Co、V、Cr、Ni)显著亏损。低钛玄武岩浆受到陆壳物质的明显混染,高钛玄武岩浆也受到混染,但混染程度弱于低钛玄武岩浆。同化混染对Sr同位素和大离子亲石元素的影响程度大于对稀土元素和Nd同位素的影响程度。混染物是下地壳变质岩,也有少量上地壳物质。未受混染的样品具有适度亏损的Nd、Sr同位素。高钛玄武岩在岩浆演化过程中主要分离结晶相/堆晶相是单斜辉石,并有少量的斜长石。低钛玄武岩中,单斜辉石和斜长石的分离结晶作用是最主要的因素。低钛玄武岩的主体部分是在尖晶石稳定域与石榴石稳定域之间的过渡带熔融的;高钛玄武岩的主体部分是在石榴石稳定域内熔融的,极少部分是在尖晶石稳定域内熔融的。
The most main rock type of the Emeishan basalts are low-Ti basalts and high-Ti basalts, and has the few picrites. They enrich in LILE and LREE at different degrees, and deplete relatively to HREE, REE fractionate evidently, compatible elements ( Co, V, Cr, Ni) deplete significantly. Low-Ti basalt magma was obviously contaminated by continent crust, in a larger extent than high-Ti basalt magma. And influences of contamination on Sr isotope and LILE are more evident than those on Nd isotope and REE. Nd and Sr isotope prove that contamination materials are mainly metamorphic rocks of lower continent crust, but also have minor rocks of upper continent crust. That the samples were not contaminated shows Nd and Sr isotopic compositions of moderately depleted mantle. Clinopyroxenes are main fractional crystallization phases/ accumulation phases, plagioclases are minor in differentiation processes of high-Mg tholeiitic magma. However, clinopyroxenes and plagioclases are main fractional crystallization phases/ accumulation phases of high-Mg transitional magma. Main body part of low-Ti basalts melted around the spinel-garnet transition zone; but main body part of high-Ti basalts melted within the garnet stability field. extremely few are partial melting within the spinel stability field.
The most main rock type of the Emeishan basalts are low-Ti basalts and high-Ti basalts, and has the few picrites. They enrich in LILE and LREE at different degrees, and deplete relatively to HREE, REE fractionate evidently, compatible elements ( Co, V, Cr, Ni) deplete significantly. Low-Ti basalt magma was obviously contaminated by continent crust, in a larger extent than high-Ti basalt magma. And influences of contamination on Sr isotope and LILE are more evident than those on Nd isotope and REE. Nd and Sr isotope prove that contamination materials are mainly metamorphic rocks of lower continent crust, but also have minor rocks of upper continent crust. That the samples were not contaminated shows Nd and Sr isotopic compositions of moderately depleted mantle. Clinopyroxenes are main fractional crystallization phases/ accumulation phases, plagioclases are minor in differentiation processes of high-Mg tholeiitic magma. However, clinopyroxenes and plagioclases are main fractional crystallization phases/ accumulation phases of high-Mg transitional magma. Main body part of low-Ti basalts melted around the spinel-garnet transition zone; but main body part of high-Ti basalts melted within the garnet stability field. extremely few are partial melting within the spinel stability field.
引文
① 云南省地质局第二区域地质调查大队.1978. 鲁甸幅1:20万区调报告
② 云南省地质局第一区域地质测量大队.1973. 大理幅1:20万区调报告
Barker JA, Menzies MA, Thirlwall MF and Macpherson CG. 1997. Petrogenesis of Quaternary intraplate volcanism, Sana' a Yenmea: Implication and polybaric melt hybridization Journal of Petrology, 38:1359-1390
Barnes SJ, Naldrett AJ and Gorton MP. 1985. The origin of the ractionation of platinum-group elements in teirestrialmagmas. Chem. Geol. , 53:303 323
Campbell IH and Griffiths RW. 1993. The evolution of mantle's chemical structrure. Lithos, 30: 389-399
Condie KC. 2001. Mantle Plumes and Their Record in Earth History. Cambridge:Cambridge University Press, 305
Evensen NM, Hamilton PJ and O'Nions RK. 1978. Rare earth abundance in chondritic meterorites. Geochim. Cosmochim. Acta, 42:1199-1212
Fan WM, Zhang CH, Wang YJ, Guo F and Peng TP. 2008. Geochronology and geochemistry of Permian basalts in western Guangxi Province, Southwest China: Evidence for plume-lithosphere interaction. Lithos, 102:218-236
Faure G. 1986. Principles of Isotope Geology. John Wiley and Sons, 142-247
Hawkesworth CJ, Blake S, Evans P et al. 2000. Time Scales of crystal fraction in magmas chamber integrating physical isotopic and geochemieal perspective. Journal of Petrology, 41:991-1006
He B, Xu YG, Chung SL, Wang YM and Luo ZY. 2006. Sedimentation and lithofacies paleogeography in southwestern China before and after the Emeishan flood volcanism: New insights into surface response tomantle plumeactivity. Journal of Petrology, 114: 117-132
He B, Xu YG, Chung SL, Xiao L and Wang YM. 2003. Sedimentary evidence for a rapid, kilometer-scale crustal doming prior to the eruption of the Emeishan flood basalts. Earth Planet. Sci. Lett. , 213:391-405
He B, Xu YG, Wang YM, Luo ZY and Wang KM. 2005. The magnitude of crustal uplift prior to the eruption of the Emeishan basalt: inferred from sedimentary records. Geotectonica et Metallogenia, 29 (3) : 316-320(in Chinese)
Hou ZQ, Lu JR, Wang YL, Xia LQ, Li HY and Guo LJ. 1999. Emei large igneous province: structure, origin and characteristics. Geological Review, 45(Suppl.): 885-890(in Chinese)
Henderson P. 1984. Rare earth element geochemistry. New York: Elsevier Science Publishers BV,23-28
Hofmann W. 1988. Chemical differentiation of the earth: The relationship between mantle, continental crust, and oceanic crust. Earth and Planetary Science Letters, 90:297-314
Irvine TN and Baragar WRA. 1971. A guide to the chemical classification of the common volcanic rocks. Canadian Journal Earth Science, 8 :523-548
Jiang CY, Jiang HB, Ye SF, Xia MZ and Lu DX. 2005 a. Petrochemical Characteristics, Nd, Sr, Pb Isotopic Compositions and Petrogenesis of Permian Dike Group, Kuruktag Region, Xinjiang. Acta Geologica Sinica, 79(6) : 823-833(in Chinese with English abstract)
Jiang CY, Lu DR, Bai KY, Zhang PB, Ye SF, Feng JX and Chen WG. 2005b. Metasomatism products of continental lithosphere mantle: Roseite deposits, Qieganbulake. Acta Petrologica Sinica, 21 (1) : 201-210(in Chinese with English abstract)
Kuno H. 1966. Lateral variation of basalt magma types across continental margins and island arcs. Bulletin Volcanologique, 29: 195-222
Mecdonald R, Rogers NW, Fitton JG et al. 2001. Plume-Lithosphere interactions in the generation of the basalts of the Kenya Rift, East Africa. Journal of Petrology, 42:877-900
Spath A, Roex AP et al. 2001. Plume-lithosphere interaction and the origin of continental rift-related alualine volcanism-the Chyulu Hills Volcanic Province, Southern Kenya. Journal of Petrology ,42:765-787
Staudigel H and Hart SR. 1983. Alteration of basaltic glass: Mechanisms and significance for the oceanic crust-seawater budget. Geochim. Cosmochim. Acta 47, 337-350
Stanley CR and Russell JK. 1989. Petrologic hypothesis testing with pearoe element ration diagrams derivation of diagram axes. Contrib. Mineral. Petro. ,101:78-89
Sun SS and McDonough WF. 1989. Chemical and isotopic systematics of oceanic basalts: Implications for mantle composition and processes. Geological Society. London, Special Publication, 42:313-345
Song XY, Hou ZQ, Cao ZM, Lu JR, Wang YL, Zhang CJ and Li YG. 2001. Geoehemieal characteristics and period of the Emei igneous province. Acta Geologica Sinica, 75 (4) :498-505 (in Chinese)
Wang K, Plant T, Walker JD and Smith EI. 2002. A mantle melting profile across the basin and range, SW USA. Journal of Geophysical Research, 107. 10. 1029/2001JB000209
Wang YL, Hughes SS, Dong CH, Xiong SH, Li JC, Li RS and Li JL. 1987. Geochemistry and continental mantle evolution of the Emeishan basalts. Journal of Chengdu College of Geology, 14(3) : 59-73(in Chinese)
Xiao L, Xu YG, Mei HJ and Sha SS. 2003a. Geochemistry of Emeishan flood basalts at Binchuan area, SW China: rock types and temporal evolution. Chinese Journal of Geology, 38 (4) :478-494 (in Chinese)
Xiao L, Xu YG and He B. 2003 b. Emei mantle plume-subcontinental lithosphere interaction: Sr-Nd, and O isotopic evidence from low-Ti and high-Ti Basalts. Geological Journal of China Universities, 9(2) :207-217(in Chinese with English abstract)
Xiao L, Xu YG, Mei HJ, Zheng YF, He B and Pirajno F. 2004. Distinct mantle sources of low-Ti and high-Ti basalts from the western Emeishan large igneous province, SW China: Implications for plume lithosphere interaction. Earth and Planetary Science Letters, 228:525-546
Xu YG and Chung S L. 2001. The Emeishan large igneous province: Evidence for mantle plume activity and melting conditions. Geochimica, 30(1) :1-9(in Chinese with English abstract)
Xu YG, He B, Chung SL, Menzies MA and Frey FA. 2004. Geological, geochemical, and geophysical consequences of plume involvement in the Emeishan flood-basalt province. Geology, 32:917-920
Xu YG, Chung SL, Jahn BM and Wu GY. 2001. Petrologic and geoehemieal constraints on the petrogenesis of Permian-Triassic Emeishan flood basalts in southwestern China. Lithos, 58: 145-168
Zhang ZC and Wang FS. 2003. Sr, Nd and Pb isotopic characteristics of Emeishan Basalt province and discussion on their source region. Earth Science, 28(4) :431-439(in Chinese with English abstract)
Zhang ZC, Wang FS, Fan WM, Deng HL, Xu YG, Xu JF and Wang YJ. 2001. A discussion on some problems concerning the study of the Emeishan basalts. Acta Petrologica et Mineralogica, 20(3) :239-246(in Chinese with English abstract)
Zhang ZC, Wang FS, Hao YL and Mahoney JJ. 2004. Geochemistry of the picrites and associated basalts from the Emeishan large igneous basalt province and constraints on their source region. Acta Geologica Sinica, 78 (2) : 171-180 (in Chinese with English abstract)
何斌,徐义刚,王雅玫,罗震宇,王康明.2005. 用沉积记录来估计峨眉山玄武岩喷发前的地壳抬升幅度.大地构造与成矿学,29(3) :316-320
侯增谦,卢记仁,汪云亮,夏林圻,李红阳,国连杰.1999. 峨眉火成岩省:结构、成因、与特色.地质论评,45(增刊):885-890
姜常义,姜寒冰,叶书锋,夏明哲,逯东霞.2005a.新疆库鲁克塔格地区二叠纪脉岩群岩石地球化学特征,Nd、Sr、Pb同位素组成与岩石成因.地质学报,79(6) :823-833
姜常义,卢登蓉,白开寅,张蓬勃,叶书锋,冯金星,陈文革.2005b.大陆岩石圈地幔交代作用的产物--且干布拉克蛭石矿床.岩石学报,21(1) :201-210
宋谢炎,侯增谦,曹志敏,卢记仁,汪云亮,张成江,李佑国.2001. 峨眉大火成岩省的岩石地球化学特征及时限.地质学报,75(4) :498-505
汪云亮,Hughes SS,童纯菡,熊舜华,李巨初,李蓉生,李建林. 1987. 峨眉山玄武岩地球化学和大陆地幔演化.成都地质学院学报,14(3) :59-73
肖龙,徐义刚,梅厚钧,沙绍礼.2003a.云南宾川地区峨眉山玄武岩地球化学特征:岩石类型及随时间演化规律.地质科学,38(4) :478-494
肖龙,徐义刚,何斌.2003b.峨眉地幔柱-岩石圈的相互作用:来自低钛和高钛玄武岩的Sr-Nd和O同位素的证据.高校地质学报,9(2) :207-217
徐义刚,钟孙霖.2001. 峨眉山大火成岩省:地幔柱活动的证据及其熔融条件.地球化学,30(1) :1-9
张招崇,王福生.2003. 峨眉山玄武岩Sr,Nd,Pb同位素特征及其物源探讨.地球科学,28(4) :431-439
张招崇,王福生,郝艳丽,Mahoney JJ.2004. 峨眉山大火成岩省中苦橄岩与其共生岩石的地球化学特征及其对源区的约束.地质学报,78(2) :171-180
张招崇,王福生,范蔚茗,邓海琳,徐义刚,许继峰,王岳军.2001. 峨眉山玄武岩研究中的一些问题的讨论.岩石矿物学杂志,20(3) :239-246
② 云南省地质局第一区域地质测量大队.1973. 大理幅1:20万区调报告
Barker JA, Menzies MA, Thirlwall MF and Macpherson CG. 1997. Petrogenesis of Quaternary intraplate volcanism, Sana' a Yenmea: Implication and polybaric melt hybridization Journal of Petrology, 38:1359-1390
Barnes SJ, Naldrett AJ and Gorton MP. 1985. The origin of the ractionation of platinum-group elements in teirestrialmagmas. Chem. Geol. , 53:303 323
Campbell IH and Griffiths RW. 1993. The evolution of mantle's chemical structrure. Lithos, 30: 389-399
Condie KC. 2001. Mantle Plumes and Their Record in Earth History. Cambridge:Cambridge University Press, 305
Evensen NM, Hamilton PJ and O'Nions RK. 1978. Rare earth abundance in chondritic meterorites. Geochim. Cosmochim. Acta, 42:1199-1212
Fan WM, Zhang CH, Wang YJ, Guo F and Peng TP. 2008. Geochronology and geochemistry of Permian basalts in western Guangxi Province, Southwest China: Evidence for plume-lithosphere interaction. Lithos, 102:218-236
Faure G. 1986. Principles of Isotope Geology. John Wiley and Sons, 142-247
Hawkesworth CJ, Blake S, Evans P et al. 2000. Time Scales of crystal fraction in magmas chamber integrating physical isotopic and geochemieal perspective. Journal of Petrology, 41:991-1006
He B, Xu YG, Chung SL, Wang YM and Luo ZY. 2006. Sedimentation and lithofacies paleogeography in southwestern China before and after the Emeishan flood volcanism: New insights into surface response tomantle plumeactivity. Journal of Petrology, 114: 117-132
He B, Xu YG, Chung SL, Xiao L and Wang YM. 2003. Sedimentary evidence for a rapid, kilometer-scale crustal doming prior to the eruption of the Emeishan flood basalts. Earth Planet. Sci. Lett. , 213:391-405
He B, Xu YG, Wang YM, Luo ZY and Wang KM. 2005. The magnitude of crustal uplift prior to the eruption of the Emeishan basalt: inferred from sedimentary records. Geotectonica et Metallogenia, 29 (3) : 316-320(in Chinese)
Hou ZQ, Lu JR, Wang YL, Xia LQ, Li HY and Guo LJ. 1999. Emei large igneous province: structure, origin and characteristics. Geological Review, 45(Suppl.): 885-890(in Chinese)
Henderson P. 1984. Rare earth element geochemistry. New York: Elsevier Science Publishers BV,23-28
Hofmann W. 1988. Chemical differentiation of the earth: The relationship between mantle, continental crust, and oceanic crust. Earth and Planetary Science Letters, 90:297-314
Irvine TN and Baragar WRA. 1971. A guide to the chemical classification of the common volcanic rocks. Canadian Journal Earth Science, 8 :523-548
Jiang CY, Jiang HB, Ye SF, Xia MZ and Lu DX. 2005 a. Petrochemical Characteristics, Nd, Sr, Pb Isotopic Compositions and Petrogenesis of Permian Dike Group, Kuruktag Region, Xinjiang. Acta Geologica Sinica, 79(6) : 823-833(in Chinese with English abstract)
Jiang CY, Lu DR, Bai KY, Zhang PB, Ye SF, Feng JX and Chen WG. 2005b. Metasomatism products of continental lithosphere mantle: Roseite deposits, Qieganbulake. Acta Petrologica Sinica, 21 (1) : 201-210(in Chinese with English abstract)
Kuno H. 1966. Lateral variation of basalt magma types across continental margins and island arcs. Bulletin Volcanologique, 29: 195-222
Mecdonald R, Rogers NW, Fitton JG et al. 2001. Plume-Lithosphere interactions in the generation of the basalts of the Kenya Rift, East Africa. Journal of Petrology, 42:877-900
Spath A, Roex AP et al. 2001. Plume-lithosphere interaction and the origin of continental rift-related alualine volcanism-the Chyulu Hills Volcanic Province, Southern Kenya. Journal of Petrology ,42:765-787
Staudigel H and Hart SR. 1983. Alteration of basaltic glass: Mechanisms and significance for the oceanic crust-seawater budget. Geochim. Cosmochim. Acta 47, 337-350
Stanley CR and Russell JK. 1989. Petrologic hypothesis testing with pearoe element ration diagrams derivation of diagram axes. Contrib. Mineral. Petro. ,101:78-89
Sun SS and McDonough WF. 1989. Chemical and isotopic systematics of oceanic basalts: Implications for mantle composition and processes. Geological Society. London, Special Publication, 42:313-345
Song XY, Hou ZQ, Cao ZM, Lu JR, Wang YL, Zhang CJ and Li YG. 2001. Geoehemieal characteristics and period of the Emei igneous province. Acta Geologica Sinica, 75 (4) :498-505 (in Chinese)
Wang K, Plant T, Walker JD and Smith EI. 2002. A mantle melting profile across the basin and range, SW USA. Journal of Geophysical Research, 107. 10. 1029/2001JB000209
Wang YL, Hughes SS, Dong CH, Xiong SH, Li JC, Li RS and Li JL. 1987. Geochemistry and continental mantle evolution of the Emeishan basalts. Journal of Chengdu College of Geology, 14(3) : 59-73(in Chinese)
Xiao L, Xu YG, Mei HJ and Sha SS. 2003a. Geochemistry of Emeishan flood basalts at Binchuan area, SW China: rock types and temporal evolution. Chinese Journal of Geology, 38 (4) :478-494 (in Chinese)
Xiao L, Xu YG and He B. 2003 b. Emei mantle plume-subcontinental lithosphere interaction: Sr-Nd, and O isotopic evidence from low-Ti and high-Ti Basalts. Geological Journal of China Universities, 9(2) :207-217(in Chinese with English abstract)
Xiao L, Xu YG, Mei HJ, Zheng YF, He B and Pirajno F. 2004. Distinct mantle sources of low-Ti and high-Ti basalts from the western Emeishan large igneous province, SW China: Implications for plume lithosphere interaction. Earth and Planetary Science Letters, 228:525-546
Xu YG and Chung S L. 2001. The Emeishan large igneous province: Evidence for mantle plume activity and melting conditions. Geochimica, 30(1) :1-9(in Chinese with English abstract)
Xu YG, He B, Chung SL, Menzies MA and Frey FA. 2004. Geological, geochemical, and geophysical consequences of plume involvement in the Emeishan flood-basalt province. Geology, 32:917-920
Xu YG, Chung SL, Jahn BM and Wu GY. 2001. Petrologic and geoehemieal constraints on the petrogenesis of Permian-Triassic Emeishan flood basalts in southwestern China. Lithos, 58: 145-168
Zhang ZC and Wang FS. 2003. Sr, Nd and Pb isotopic characteristics of Emeishan Basalt province and discussion on their source region. Earth Science, 28(4) :431-439(in Chinese with English abstract)
Zhang ZC, Wang FS, Fan WM, Deng HL, Xu YG, Xu JF and Wang YJ. 2001. A discussion on some problems concerning the study of the Emeishan basalts. Acta Petrologica et Mineralogica, 20(3) :239-246(in Chinese with English abstract)
Zhang ZC, Wang FS, Hao YL and Mahoney JJ. 2004. Geochemistry of the picrites and associated basalts from the Emeishan large igneous basalt province and constraints on their source region. Acta Geologica Sinica, 78 (2) : 171-180 (in Chinese with English abstract)
何斌,徐义刚,王雅玫,罗震宇,王康明.2005. 用沉积记录来估计峨眉山玄武岩喷发前的地壳抬升幅度.大地构造与成矿学,29(3) :316-320
侯增谦,卢记仁,汪云亮,夏林圻,李红阳,国连杰.1999. 峨眉火成岩省:结构、成因、与特色.地质论评,45(增刊):885-890
姜常义,姜寒冰,叶书锋,夏明哲,逯东霞.2005a.新疆库鲁克塔格地区二叠纪脉岩群岩石地球化学特征,Nd、Sr、Pb同位素组成与岩石成因.地质学报,79(6) :823-833
姜常义,卢登蓉,白开寅,张蓬勃,叶书锋,冯金星,陈文革.2005b.大陆岩石圈地幔交代作用的产物--且干布拉克蛭石矿床.岩石学报,21(1) :201-210
宋谢炎,侯增谦,曹志敏,卢记仁,汪云亮,张成江,李佑国.2001. 峨眉大火成岩省的岩石地球化学特征及时限.地质学报,75(4) :498-505
汪云亮,Hughes SS,童纯菡,熊舜华,李巨初,李蓉生,李建林. 1987. 峨眉山玄武岩地球化学和大陆地幔演化.成都地质学院学报,14(3) :59-73
肖龙,徐义刚,梅厚钧,沙绍礼.2003a.云南宾川地区峨眉山玄武岩地球化学特征:岩石类型及随时间演化规律.地质科学,38(4) :478-494
肖龙,徐义刚,何斌.2003b.峨眉地幔柱-岩石圈的相互作用:来自低钛和高钛玄武岩的Sr-Nd和O同位素的证据.高校地质学报,9(2) :207-217
徐义刚,钟孙霖.2001. 峨眉山大火成岩省:地幔柱活动的证据及其熔融条件.地球化学,30(1) :1-9
张招崇,王福生.2003. 峨眉山玄武岩Sr,Nd,Pb同位素特征及其物源探讨.地球科学,28(4) :431-439
张招崇,王福生,郝艳丽,Mahoney JJ.2004. 峨眉山大火成岩省中苦橄岩与其共生岩石的地球化学特征及其对源区的约束.地质学报,78(2) :171-180
张招崇,王福生,范蔚茗,邓海琳,徐义刚,许继峰,王岳军.2001. 峨眉山玄武岩研究中的一些问题的讨论.岩石矿物学杂志,20(3) :239-246
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