Abstract
The last eruptions of the monogenetic Bakony-Balaton Highland Volcanic Field (western Pannonian Basin, Hungary) produced unusually crystal- and xenolith-rich alkaline basalts which are unique among the alkaline basalts of the Carpathian–Pannonian Region. Similar alkaline basalts are only rarely known in other volcanic fields of the world. These special basaltic magmas fed the eruptions of two closely located volcanic centres: the Bondoró-hegy and the Füzes-tó scoria cone. Their uncommon enrichment in diverse crystals produced unique rock textures and modified original magma compositions (13.1–14.2 wt.% MgO, 459–657 ppm Cr, and 455–564 ppm Ni contents). Detailed mineral-scale textural and chemical analyses revealed that the Bondoró-hegy and Füzes-tó alkaline basaltic magmas have a complex ascent history, and that most of their minerals (∼30 vol.% of the rocks) represent foreign crystals derived from different levels of the underlying lithosphere. The most abundant xenocrysts, olivine, orthopyroxene, clinopyroxene, and spinel, were incorporated from different regions and rock types of the subcontinental lithospheric mantle. Megacrysts of clinopyroxene and spinel could have originated from pegmatitic veins/sills which probably represent magmas crystallized near the crust–mantle boundary. Green clinopyroxene xenocrysts could have been derived from lower crustal mafic granulites. Minerals that crystallized in situ from the alkaline basaltic melts (olivine with Cr-spinel inclusions, clinopyroxene, plagioclase, and Fe–Ti oxides) are only represented by microphenocrysts and overgrowths on the foreign crystals. The vast amount of peridotitic (most common) and mafic granulitic materials indicates a highly effective interaction between the ascending magmas and wall rocks at lithospheric mantle and lower crustal levels. However, fragments from the middle and upper crust are absent from the studied basalts, suggesting a change in the style (and possibly rate) of magma ascent in the crust. These xenocryst- and xenolith-rich basalts yield divers tools for estimating magma ascent rate that is important for hazard forecasting in monogenetic volcanic fields. According to the estimated ascent rates, the Bondoró-hegy and Füzes-tó alkaline basaltic magmas could have reached the surface within hours to few days, similarly to the estimates for other eruptive centres in the Pannonian Basin which were fed by “normal” (crystal and xenoliths poor) alkaline basalts.
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References
Ancochea E, Munoz M, Sagredo J (1987) Las rocas volcánicas neógenas de Nuévalos (provincia de Zaragoza). Geogaceta 3:7–10
Aoki K-i, Kushiro I (1968) Some clinopyroxenes from ultramafic inclusions in Dreiser Weiher, Eifel. Contrib Mineral Petrol 18(4):326–337
Arai S, Abe N (1995) Reaction of orthopyroxene in peridotite xenoliths with alkali-basalt melt and its implication for genesis of alpine-type chromitite. Am Mineral 80:1041–1047
Bada G, Horváth F (2001) On the structure and tectonic of the Pannonian Basin and surrounding orogens. Acta Geol Hung 44(2–3):301–327
Balogh K, Pécskay Z (2001) K/Ar and Ar/Ar geochronological studies in the Pannonian–Carpathians–Dinarides (PANCARDI) region. Acta Geol Hung 44:281–299
Balogh K, Árva-Sós E, Pécskay Z, Ravasz-Baranyai L (1986) K/Ar dating of post-Sarmatian alkali basaltic rocks in Hungary. Acta Mineral Petrogr Szeged 28:75–93
Barton M, Bergen VMJ (1981) Green clinopyroxenes and associated phases in a potassium-rich lava from the Leucite Hills, Wyoming. Contrib Mineral Petrol 77(2):101–114
Best MG (2003) Igneous and metamorphic petrology. Blackwell, New York
Binns RA, Duggan MB, Wilkinson JFG (1970) High pressure megacrysts in alkaline lavas from northeastern New South Wales. Am J Sci 269(2):132–168
Boudier F (1991) Olivine xenocrysts in picritic magmas: An experimental and microstructural study. Contrib Mineral Petrol 109(1):114–123
Bowen NL, Anderson O (1914) The binary system MgO–SiO2. Am J Sci 37:487–500
Brearley M, Scarfe CM (1986) Dissolution rates of upper mantle minerals in an alkali basalt melt at high pressure: an experimental study and implications for ultramafic xenolith survival. J Petrol 27(5):1157–1182
Brenna M, Cronin SJ, Smith IEM, Sohn YK, Németh K (2010) Mechanisms driving polymagmatic activity at a monogenetic volcano, Udo, Jeju Island, South Korea. Contrib Mineral Petrol 160(6):931–950
Brenna M, Cronin SJ, Németh K, Smith IEM, Sohn YK (2011) The influence of magma plumbing complexity on monogenetic eruptions, Jeju Island, Korea. Terra Nova, pp. 1–6
Brooks CK, Printzlau I (1978) Magma mixing in mafic alkaline volcanic rocks: The evidence from relict phenocryst phases and other inclusions. J Volcanol Geotherm Res 4:315–331
Carracedo J-C, Perez-Torrado F-J, Rodriguez-Gonzalez A, Fernandez-Turiel J-L, Klügel A, Troll VR, Wiesmaier S (2012) The ongoing volcanic eruption of El Hierro. Eos Trans AGU, Canary Islands, 93(9)
Connor CB, Conway FM (2000) Basaltic volcanic fields. In: Sigurdsson H (ed) Encyclopedia of volcanoes. Academic Press, San Diego, pp 331–343
Costa F, Cohmen R, Chakraborty S (2008) Time Scales of Magmatic Processes from Modeling the Zoning Patterns of Crystals. In: Putirka KD, Tepley III FJ (eds) Minerals, Inclusions and Volcanic Processes. Mineralogical Society of America & Geochemical Society, pp 545–594
Csontos L, Nagymarosy A, Horváth F, Kovác M (1992) Tertiary evolution of the Intra-Carpathian area: a model. Tectonophysics 208(1–3):221–241
Daines MJ, Kohlstedt DL (1994) The transition from porous to channelized flow due to melt/rock reaction during melt migration. Geophys Res Lett 21(2):145–148
Deer WA, Howie RA, Zussman J (1978) Rock-forming minerals. Vol. 2A. Single-chain silicates, Longman, London, pp 3–4
Dégi J, Abart R, Török K, Rhede D, Petrishcheva E (2009) Evidence for xenolith-host basalt interaction from chemical patterns in Fe-Ti-oxides from mafic granulite xenoliths of the Bakony-Balaton Volcanic field (W-Hungary). Mineral Petrol 95(3):219–234
Dobosi G (1989) Clinopyroxene zoning patterns in the young alkali basalts of Hungary and their petrogenetic significance. Contrib Mineral Petrol 101:112–121
Dobosi G, Fodor RV (1992) Magma fractionation, replenishment, and mixing as inferred from green-core clinopyroxenes in Pliocene basanite, southern Slovakia. Lithos 28(2):133–150
Dobosi G, Schultz-Güttler R, Kurat G, Kracher A (1991) Pyroxene chemistry and evolution of alkali basaltic rocks from Burgenland and Styria, Austria. Mineral Petrol 43(4):275–292
Dobosi G, Downes H, Embey-Isztin A, Jenner GA (2003) Origin of megacrysts and pyroxenite xenoliths from the Pliocene alkali basalts of the Pannonian Basin (Hungary). Neues Jahrbuch für Mineralogie-Abhandlungen 178(3):217–237
Downes H, Vaselli O (1995) The lithospheric mantle beneath the Carpathian–Pannonian Region: a review of trace element and isotopic evidence from ultramafic xenoliths. In: Downes H, Vaselli O (eds) Neogene and Related Magmatism in the Carpatho-Pannonian Region. Acta Vulcanologica, pp 219–229
Downes H, Embey-Isztin A, Thirlwall MF (1992) Petrology and geochemistry of spinel peridotite xenoliths from the western Pannonian Basin (Hungary): evidence for an association between enrichment and texture in the upper mantle. Contrib Mineral Petrol 109(3):340–354
Duda A, Schmincke H-U (1985) Polybaric differentiation of alkali basaltic magmas: evidence from green-core clinopyroxenes (Eifel, FRG). Contrib Mineral Petrol 91(4):340–353
Ellis DJ (1976) High pressure cognate inclusions in the Newer Volcanics of Victoria. Contrib Mineral Petrol 58(2):149–180
Embey-Isztin A (1976) Amphibolite/lherzolite composite xenolith from Szigliget, north of the lake Balaton, Hungary. Earth Planet Sci Lett 31(2):297–304
Embey-Isztin A, Dobosi G (1995) Mantle source characteristics for Miocene-Pleistocene alkali basalts, Carpathian–Pannonian Region: a review of trace elements and isotopic composition. In: Downes H, Vaselli O (eds) Neogene and Related Magmatism in the Carpatho-Pannonian Region. Acta Vulcanologica, pp 155–166
Embey-Isztin A, Scharbert HG, Dietrich H, Poultidis H (1989) Petrology and Geochemistry of peridotite xenoliths in alkali basalts from the transdanubian volcanic region, West Hungary. J Petrol 30(1):79–105
Embey-Isztin A, Scharbert HG, Dietrich H, Poultidis H (1990) Mafic granulites and clinopyroxenite xenoliths from the Transdanubian Volcanic Region (Hungary): implications for the deep structure of the Pannonian Basin. Mineral Mag 54:463–483
Embey-Isztin A, Dobosi G, James D, Downes H, Poultidis C, Scharbert HG (1993a) A compilation of new major, trace and isotope geochemical analyses of the young alkali basalts from the Pannonian Basin. Fragm Mineral Palaeontol 16:5–26
Embey-Isztin A, Downes H, James DE, Upton BGJ, Dobosi G, Ingram GA, Harmon RS, Scharbert HG (1993b) The petrogenesis of Pliocene alkaline volcanic rocks from the Pannonian Basin, Eastern Central Europe. J Petrol 34:317–343
Embey-Isztin A, Dobosi G, Altherr R, Meyer H-P (2001a) Thermal evolution of the lithosphere beneath the western Pannonian Basin: evidence from deep-seated xenoliths. Tectonophysics 331(3):285–306
Embey-Isztin A, Downes H, Dobosi G (2001b) Geochemical characterization of the Pannonian Basin mantle lithosphere and asthenosphere: an overview. Acta Geol Hung 44(2–3):259–280
Embey-Isztin A, Downes H, Kempton PD, Dobosi G, Thirlwall M (2003) Lower crustal granulite xenoliths from the Pannonian Basin, Hungary. Part 1: mineral chemistry, thermobarometry and petrology. Contrib Mineral Petrol 144:652–670
Fodor L, Csontos L, Bada G, Benkovics L, Györfi I (1999) Tertiary tectonic evolution of the Carpatho-Pannonian region: A new synthesis of palaeostress data. In: Durand B, Jolivet L, F. H, Séranne M (eds) The Mediterranean Basins: tertiary extension within the Alpine Orogen. Geological Society, London, Special Publications, pp 295–334
Granet M, Wilson M, Achauer U (1995) Imaging a mantle plume beneath the French Massif Central. Earth Planet Sci Lett 136(3–4):281–296
Gurenko AA, Hansteen TH, Schmincke H-U (1996) Evolution of parental magmas of Miocene shield basalts of Gran Canaria (Canary Islands): constraints from crystal, melt and fluid inclusions in minerals. Contrib Mineral Petrol 124(3):422–435
Harangi S (2001) Volcanology and petrology of the Late Miocene to Pliocene alkali basaltic volcanism in the Western Pannonian Basin. In: Ádám A, Szarka L (eds) PANCARDI 2001 Field Guide. Sopron, pp 51–81
Harangi S (2009) Volcanism of the Carpathian–Pannonian region, Europe: the role of subduction, extension and mantle plumes. In: http://www.mantleplumes.org/CarpathianPannonian.html
Harangi S, Lenkey L (2007) Genesis of the Neogene to Quaternary volcanism in the Carpathian–Pannonian region: role of subduction, extension, and mantle plume. Geol Soc Am Spec Pap 418:67–92
Harangi S, Sági T, Seghedi I, Ntaflos T (2013) A mineral-scale investigation to reveal the origin of the basaltic magmas of the Perşani monogenetic volcanic field, Romania, eastern-central Europe. Lithos
Hasenaka T, Carmichael ISE (1985) The cinder cones of Michoacán-Guanajuato, central Mexico: their age, volume and distribution, and magma discharge rate. J Volcanol Geotherm Res 25(1–2):105–124
Hidas K, Falus G, Szabó C, Szabó PJ, Kovács I, Földes T (2007) Geodynamic implications of flattened tabular equigranular textured peridotites from the Bakony-Balaton Highland Volcanic Field (Western Hungary). J Geodyn 43(4–5):484–503
Hildner E, Kügel A, Hansteen TH (2012) Barometry of lavas from the 1951 eruption of Fogo, Cape Verde Islands: Implications for historic and prehistoric magma plumbing systems. J Volcanol Geotherm Res 217–218:73–90
Hirano N, Yamamoto J, Kagi H, Ishii T (2004) Young, olivine xenocryst-bearing alkali-basalt from the oceanward slope of the Japan Trench. Contrib Mineral Petrol 148(1):47–54
Hoernle K, Zhang YS, Graham D (1995) Seismic and geochemical evidence for large-scale mantle upwelling beneath the eastern Atlantic and western and central Europe. Nature 374:34–39
Horváth F (1993) Towards a mechanical model for the formation of the Pannonian Basin. Tectonophysics 226(1–4):333–357
Horváth F (1995) Phases of compression during the evolution of the Pannonian Basin and its bearing on hydrocarbon exploration. Mar Pet Geol 12(8):837–844
Horváth F, Cloetingh S (1996) Stress-induced late-stage subsidence anomalies in the Pannonian Basin. Tectonophysics 266(1–4):287–300
Irving AJ, Frey FA (1984) Trace element abundances in megacrysts and their host basalts: constraints on partition coefficients and megacryst genesis. Geochim Cosmochim Acta 48(6):1201–1221
Jankovics É, Harangi S, Ntaflos T (2009) A mineral-scale investigation on the origin of the 2.6 Ma Füzes-tó basalt, Bakony-Balaton Highland Volcanic Field (Pannonian Basin, Hungary). Cent Eur Geol 52(2):97–124
Jankovics MÉ, Harangi S, Kiss B, Ntaflos T (2012) Open-system evolution of the Füzes-tó alkaline basaltic magma, western Pannonian Basin: constraints from mineral textures and compositions. Lithos 140–141:25–37
Jugovics L (1968) The Transdanubian basalt and basaltic tuff fields (in Hungarian). Yearly Report of the Hungarian Geological Institute about the year 1967, pp 75–82
Jugovics L (1976) The chemical character of the Hungarian basalts (in Hungarian). Yearly report of the Hungarian Geological Institute about the year 1974, pp 431–470
Jurewicz AJG, Watson EB (1988) Cations in olivine, part 2: diffusion in olivine xenocrysts, with applications to petrology and mineral physics. Contrib Mineral Petrol 99(2):186–201
Kereszturi G, Csillag G, Németh K, Sebe K, Balogh K, Jáger V (2010) Volcanic architecture, eruption mechanism and landform evolution of a Plio/Pleistocene intracontinental basaltic polycyclic monogenetic volcano from the Bakony-Balaton Highland Volcanic Field, Hungary. Cent Eur J Geosci 2(3):362–384
Klügel A (1998) Reactions between mantle xenoliths and host magma beneath La Palma (Canary Islands): constraints on magma ascent rates and crustal reservoirs. Contrib Mineral Petrol 131(2):237–257
Klügel A, Hansteen TH, Galipp K (2005) Magma storage and underplating beneath Cumbre Vieja volcano, La Palma (Canary Islands). Earth Planet Sci Lett 236(1–2):211–226
Larsen LM, Pedersen AK (2000) Processes in high-Mg, high-T Magmas: evidence from olivine, chromite and glass in palaeogene picrites from West Greenland. J Petrol 41(7):1071–1098
Lasaga AC (1998) Kinetic theory in the earth sciences. Princeton University Press, Princeton, p 728
Lenkey L, Dövényi P, Horváth F, Cloetingh S (2002) Geothermics of the Pannonian Basin and its bearing on the neotectonics. Eur Geophys Union Stephan Mueller Spec Publ 3:29–40
Lister JR, Kerr RC (1991) Fluid-mechanical models of crack propagation and their application to magma transport in dykes. J Geophys Res 96(B6):10049–10077
Maaloe S, Hansen B (1982) Olivine phenocrysts of Hawaiian olivine tholeiite and oceanite. Contrib Mineral Petrol 81(3):203–211
Martin U, Németh K (2005) Eruptive and depositional history of a Pliocene tuff ring that developed in a fluvio-lacustrine basin: Kissomlyó volcano (western Hungary). J Volcanol Geotherm Res 147(3–4):342–356
Martin U, Németh K, Auer A, Breitkreuz C (2003) Mio-Pliocene Phreatomagmatic Volcanism in a Fluvio-Lacustrine Basin in Western Hungary. Geolines 15:84–90
Mattsson HB (2012) Rapid magma ascent and short eruption durations in the Lake Natron-Engaruka monogenetic volcanic field (Tanzania): a case study of the olivine melilititic Pello Hill scoria cone. J Volcanol Geotherm Res 247–248:16–25
McGee LE, Millet M-A, Smith IEM, Németh K, Lindsay JM (2012) The inception and progression of melting in a monogenetic eruption: Motukorea Volcano, the Auckland Volcanic Field, New Zealand. Lithos 155:360–374
Morimoto N, Fabries J, Ferguson AK, Ginzburg IV, Ross M, Seifert FA, Zussman J, Aoki K, Gottardi G (1988) Nomenclature of pyroxenes. Mineral Mag 52:535–550
Needham AJ, Lindsay JM, Smith IEM, Augustinus P, Shane PA (2011) Sequential eruption of alkaline and sub-alkaline magmas from a small monogenetic volcano in the Auckland Volcanic Field, New Zealand. J Volcanol Geotherm Res 201(1–4):126–142
Németh K, Martin U (1999a) Large hydrovolcanic field in the Pannonian Basin: general characteristics of the Bakony-Balaton Highland Volcanic Field, Hungary. Acta Vulcanol 11(2):271–282
Németh K, Martin U (1999b) Late Miocene paleo-geomorphology of the Bakony-Balaton Highland Volcanic Field (Hungary) using physical volcanology data. Z Geomorphol NF 43(4):417–438
Reiners PW (2002) Temporal-compositional trends in intraplate basalt eruptions: Implications for mantle heterogeneity and melting processes. Geochemistry Geophysics Geosystems 3:1–30
Righter K, Carmichael ISE (1993) Mega-xenocrysts in alkali olivine basalts: fragments of disrupted mantle assemblages. Am Mineral 78:1230–1245
Roeder PL, Poustovetov A, Oskarsson N (2001) Growth forms and composition of chromian spinel in MORB magma: diffusion-controlled crystallization of chromian spinel. Can Mineral 39(2):397–416
Roeder PL, Thornber C, Poustovetov A, Grant A (2003) Morphology and composition of spinel in Pu’u ‘O’o lava (1996–1998), Kilauea volcano, Hawaii. J Volcanol Geotherm Res 123(3–4):245–265
Roeder P, Gofton E, Thornber C (2006) Cotectic proportions of olivine and spinel in olivine-tholeiitic basalt and evaluation of pre-eruptive processes. J Petrol 47(5):883–900
Rohrbach A, Schuth S, Ballhaus C, Münker C, Matveev S, Qopoto C (2005) Petrological constraints on the origin of arc picrites, New Georgia Group, Solomon Islands. Contrib Mineral Petrol 149(6):685–698
Ruprecht P, Bachmann O (2010) Pre-eruptive reheating during magma mixing at Quizapu volcano and the implications for the explosiveness of silicic arc volcanoes. Geology 38(10):919–922
Russell JK, Porritt LA, Lavallee Y, Dingwell DB (2012) Kimberlite ascent by assimilation-fuelled buoyancy. Nature 481(7381):352–356
Sato H (1977) Nickel content of basaltic magmas: identification of primary magmas and a measure of the degree of olivine fractionation. Lithos 10(2):113–120
Seghedi I, Downes H, Vaselli O, Szakács A, Balogh K, Pécskay Z (2004) Post-collisional Tertiary–Quaternary mafic alkalic magmatism in the Carpathian–Pannonian region: a review. Tectonophysics 393(1–4):43–62
Shane P, Gehrels M, Zawalna-Geer A, Augustinus P, Lindsay J, Chaillou I (2013) Longevity of a small shield volcano revealed by crypto-tephra studies (Rangitoto volcano, New Zealand): change in eruptive behavior of a basaltic field. J Volcanol Geotherm Res 257:174–183
Shaw CSJ (1999) Dissolution of orthopyroxene in basanitic magma between 0.4 and 2 GPa: further implications for the origin of Si-rich alkaline glass inclusions in mantle xenoliths. Contrib Mineral Petrol 135(2):114–132
Shaw C, Dingwell D (2008) Experimental peridotite-melt reaction at one atmosphere: a textural and chemical study. Contrib Mineral Petrol 155(2):199–214
Shaw CSJ, Eyzaguirre J (2000) Origin of megacrysts in the mafic alkaline lavas of the West Eifel volcanic field, Germany. Lithos 50(1–3):75–95
Shaw CSJ, Thibault Y, Edgar AD, Lloyd FE (1998) Mechanisms of orthopyroxene dissolution in silica-undersaturated melts at 1 atmosphere and implications for the origin of silica-rich glass in mantle xenoliths. Contrib Mineral Petrol 132(4):354–370
Smith DR, Leeman WP (2005) Chromian spinel-olivine phase chemistry and the origin of primitive basalts of the southern Washington Cascades. J Volcanol Geotherm Res 140(1–3):49–66
Sparks RSJ, Pinkerton H, Macdonald R (1977) The transport of xenoliths in magmas. Earth Planet Sci Lett 35(2):234–238
Sparks RSJ, Baker L, Brown RJ, Field M, Schumacher J, Stripp G, Walters A (2006) Dynamical constraints on kimberlite volcanism. J Volcanol Geotherm Res 155(1–2):18–48
Spera FJ (1984) Carbon dioxide in petrogenesis III: role of volatiles in the ascent of alkaline magma with special reference to xenolith-bearing mafic lavas. Contrib Mineral Petrol 88(3):217–232
Szabó C, Bodnar RJ (1996) Changing magma ascent rates in the Nógrád–Gömör volcanic field, Northern Hungary/Southern Slovakia: evidence from CO2-rich fluid inclusions in metasomatized upper mantle xenoliths. Petrology 4(3):221–230
Szabó C, Falus G, Zajacz Z, Kovács I, Bali E (2004) Composition and evolution of lithosphere beneath the Carpathian–Pannonian Region: a review. Tectonophysics 393(1–4):119–137
Takada A (1994) The influence of regional stress and magmatic input on styles of monogenetic and polygenetic volcanism. J Geophys Res 99(B7):13563–13573
Tari G, Dövényi P, Horváth F, Dunkl I, Lenkey L, Stefanescu M, Szafián P, Tóth T (1999) Lithospheric structure of the Pannonian Basin derived from seismic, gravity and geothermal data. In: Durand B, Jolivet L, Horváth F, Séranne M (eds) The Mediterranean Basins: Tertiary extension within the Alpine orogen. Geological Society, Special Publication, London, pp 215–250
Tracy RJ, Robinson P (1977) Zoned titanian augite in alkali olivine basalt from Tahiti and the nature of titanium substitutions in augite. Am Mineral 62(7–8):634–645
Ulrych J, Ackerman L, Balogh K, Hegner E, Jelínek E, Pécskay Z, Přichystal A, Upton BGJ, Zimák J, Foltýnová R (2013) Plio-Pleistocene basanitic and melilititic series of the Bohemian Massif: K-Ar ages, major/trace element and Sr–Nd isotopic data. Chemie der Erde—Geochemistry. doi:10.1016/j.chemer.2013.02.001
Valentine GA, Krogh KEC (2006) Emplacement of shallow dikes and sills beneath a small basaltic volcanic center – The role of pre-existing structure (Paiute Ridge, southern Nevada, USA). Earth Planet Sci Lett 246(3–4):217–230
Walker GPL (1993) Basaltic-volcano systems. Geological Society, London, Special Publications 76(1):3–38
Wass SY (1979) Multiple origins of clinopyroxenes in alkali basaltic rocks. Lithos 12(2):115–132
Wijbrans J, Németh K, Martin U, Balogh K (2007) 40Ar/39Ar geochronology of Neogene phreatomagmatic volcanism in the western Pannonian Basin, Hungary. J Volcanol Geotherm Res 164(4):193–204
Yagi K, Onuma K (1967) The join CaMgSi2O6–CaTiAl2O6 and its bearing on the titanaugites. Journal of the Faculty of Science, Hokkaido University 13(4):463–483
Zhang H-F (2005) Transformation of lithospheric mantle through peridotite-melt reaction: a case of Sino-Korean craton. Earth Planet Sci Lett 237(3–4):768–780
Acknowledgements
We are very grateful to R. V. Fodor for his valuable suggestions and comments as well as I. E. M. Smith for his useful advices which helped to improve the manuscript. This research was partly supported by the TÉT_10-1-2011-0694 project (Hungarian-Austrian Cooperation) and by the Hungarian Scientific Research Fund OTKA no. 68587. B. Kiss was funded in the frames of TÁMOP 4.2.4. A/2-11-1-2012-0001 “National Excellence Program—Elaborating and operating an inland student and researcher personal support system convergence program” and was subsidized by the European Union and co-financed by the European Social Fund.
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This paper constitutes part of a topical collection: Smith IEM, Nemeth K, and Ross P-S (eds) Monogenetic volcanism and its relevance to the evolution of volcanic fields.
Appendix: magma ascent rate estimates
Appendix: magma ascent rate estimates
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1.
Modeling—fluid filled crack-propagation velocity:
Ascent rate for alkaline basaltic magmas in general: we followed the method that Mattsson (2012) performed for melilititic magmas. Equation (8) in Sparks et al. (2006) was used, which is based on fluid filled crack propagation under turbulent conditions and assumes that magma ascending in dykes is mainly buoyancy driven (Lister and Kerr 1991). The equation contains the half-width of the feeder dyke (w) and the density contrast between the magma and the wall rock. According to Sparks et al. (2006), a dyke width (2w) of 1 m is comparable to those observed in kimberlite and basalt dykes. We studied the effects of variations in ∆ρ (ascending magma propagates through different wall rocks characterized by different densities, so ∆ρ changes during ascent) and in 2w on ascent rates. Therefore, we made three presumed scenarios using different ∆ρ (100, 200 and 300 kg/m3) and 2w values (0.5, 1 and 1.5 m) (Appendix Fig. 12a). The magma viscosity was assumed as 5.5 Pa s.
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2.
Modeling—xenolith settling rate:
According to Sparks et al. (1977), the presence of xenoliths in alkaline basalts is due not to their higher ascent rates compared with other basaltic types, but instead due to their higher yield strengths and, thus, ability to suspend solids. Spera (1984) did not agree with this theory but argued that the occurrence of ultramafic nodules in alkaline basaltic volcanics is indicative of relatively high average flow rates. He calculated xenolith settling velocities (taking into account the rheological behaviour of the magma) that give minimum estimates of magma ascent rates, and published 0.1–5 m/s ascent velocities for spinel peridotite-bearing alkaline magmas. Klügel (1998) concluded that the presence of mantle xenoliths does not necessarily imply single-stage ascent (i.e. rapid and direct ascent of their host magma), therefore xenoliths do not always indicate the absence of crustal reservoirs where magmas are stored temporarily. However, he agreed with Spera (1984) that magma ascent rates must exceed the settling rates of the largest and densest xenoliths during each ascent stage.
We used Eq. (1) of Spera (1984). The largest peridotite xenoliths found at Bondoró-hegy and Füzes-tó are 20 cm in diameter. The calculation requires the knowledge of magma viscosity (η) and the density difference (∆ρ) between xenolith and melt. The viscosity of alkaline basaltic magmas ranges between ∼10 and 550 poise (1–55 Pa s) as a function of the temperature (e.g. Best 2003). We studied the effects of variations in ∆ρ (the studied basalts contain various xenoliths which can have different densities) and in η (viscosity increases with increasing crystal content in the ascending, crystallizing magma) on ascent rates. Thus, we used three hypothetical scenarios involving different ∆ρ (400, 500, and 600 kg/m3) and η values (5.5, 10, and 35 Pa s) (Fig. 12b). 50 N/m2 yield strength (corresponding to ∼15 vol% crystallinity) was used after Spera (1984). According to Fig. 12b, the changes of these parameters cause some differences in the magma ascent rates but they are in the same order of magnitude.
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3.
Residence time of olivine xenocrysts in basaltic melt:
Time estimation from chemical profiles of crystals in magmatic rocks is based on the theory that if the melt incorporates a foreign crystal (antecryst or xenocryst), diffusion occurs to diminish the chemical disequilibrium between the host melt and the foreign crystal, and there is new growth from the host melt or a reaction texture. A diffusion concurrent with growth causes a moving-boundary problem, therefore ascertaining the single effect of each process is difficult (Costa et al. 2008). Olivine phenocryst cores crystallized in equilibrium conditions do not show zoning in Fo. However, with decreasing Mg content and temperature, they will have a smoothly curved profile (Maaloe and Hansen 1982; Larsen and Pedersen 2000). It is a similar case for a xenocrystic olivine incorporated by magma. If the melt and the grain are in equilibrium at the time of the incorporation, a simple overgrowth occurs. At disequilibrium conditions, when the liquid has too low Mg content, Fe-Mg exchange occurs between magma and xenocryst, as described by Zhang (2005). After they have equilibrated, a rim will grow on the crystal. Larsen and Pedersen (2000) mentioned that Fe–Mg exchange could modify the Fo content of olivines after a simple crystallization, i.e. the curved Fo profiles at crystal rims will straighten.
Growth and Fe–Mg exchange could be accompanied by diffusion of minor elements, like Ca and Ni. Costa et al. (2008) described that beside numerical modeling methods there is a simple way to recognize concurrent diffusion and crystal growth of olivine. The relation between Fo and Ni content of olivine is non-linear at fractionation (crystal growth), and in contrast, the linear trend is caused by diffusion only. Based on the work of Jurewicz and Wattson (1988), Lasaga (1998) created a one-dimensional model for Ca diffusion into olivine: T 1/2 = (X 1/2)2/2D, where T 1/2 is the time necessary to reach half of the equilibration concentration of Ca in olivine and X 1/2 is the distance from crystal rim to this point. The diffusion coefficient (D) for Ca in olivine is 3.18*10−12 cm2/s at 1,200 °C and fO2 = 10−8 Pa. The Ca diffusion barely depends on the orientation of the olivine (Lasaga 1998).
Our studied olivine xenocryst profiles show a Fo-rich inner plateau characterized by Ca contents lower than 500 ppm and a thin rim with sharply increasing Ca (Fig. 6a, b). According to Gurenko et al. (1996), they could be identified as mantle olivines. Relationships between Fo and NiO toward rims of olivine xenocrysts are linear (Fig. 7) indicating that diffusion was the main driving force after the incorporation. Our interpretation is that after the crystals were incorporated by the ascending magma, equilibration by diffusion, and precipitation of an overgrowth rim began.
Figure 13 shows that the Ca profile of the olivine xenocryst in Fig. 6a has a slightly tilted plateau (i.e. characterized by slightly increasing Ca contents from 343 to 515 ppm) from the inner part of the crystal towards the rim which changes abruptly at a distance of 22 μm from the crystal rim. After this inflection point the Ca content increases to 2,130 ppm. The strong enrichment of Ca in the rims corresponds to the above mentioned processes. However, the tilt in the inner plateau could be the result of a heating event—probably related to the build up of the magmatic system, when the olivine xenocryst was an integral part of the mantle and heat has reached it conductively from the accumulating basaltic magma—before the incorporation. The X 1/2 for this period is 108 μm and the evaluated heating time is 1.16 years.
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4.
Dissolution time of orthopyroxene xenocrysts:
Interaction between the alkaline basalt and orthopyroxene is a dynamic disequilibrium process, which possibly depends on the composition of the orthopyroxene, the rate of supply of undersaturated melt and other processes (Daines and Kohlstedt 1994). The reaction zone can also be interpreted as a melt-mixing zone, where the Si-rich secondary melt, derived from the incongruent melting of orthopyroxene, is mixed with the surrounding, less silicic alkaline basaltic melt (Arai and Abe 1995). In the system Fo + SiO2, enstatite breaks down at 1559 °C and at 1 atmosphere to form forsterite and silica, and the amount of olivine that should be formed on incongruent melting is approximately 5-6 % (Bowen and Anderson 1914). However, the observed amount of olivine is much more in the reaction rims. The additional olivine could crystallize from the melt of the hybrid boundary layer, formed by the mixing of the basanite melt and the liquid derived from orthopyroxene breakdown (Shaw et al. 1998). Clinopyroxene is not a normal product of the incongruent breakdown of orthopyroxene, and therefore the components required for its formation must have diffused into the boundary layer from the basanite melt (Shaw et al. 1998).
Based on the experimental results of Shaw (1999), the dissolution of orthopyroxene, i.e. the formation of the reaction rim, is a function of time and pressure. Dissolution rates were determined for anhydrous solvent melt at 0.4, 1 and 2 GPa. The experimental results indicate that the dissolution rates at 1 and 2 GPa are much faster than at 0.4 GPa under anhydrous conditions, which is in accordance with previous observations of increasing dissolution rate with increasing pressure (Brearley and Scarfe 1986). The relationship between the reaction rim thickness and the time can be expressed by a power law function of the form y = ax b where y = rim thickness, x = time, a and b are coefficients distinct for each pressure. The a and b coefficients can be obtained by fitting power law functions on the experimental data of Shaw (1999). After this, reaction rates can be determined from the thicknesses of the orthopyroxene reaction rims. The reaction rim forms where the crystal is in direct contact with the melt. Thus, the calculated reaction time gives the time that the orthopyroxene spent in the melt. This reaction rim has to form long before the eruptions and during magma ascent when the melt is capable of reaction. The reaction rims around single xenocrysts are characterized by roughly unvarying thicknesses (intracrystalline thickness), whereas the reaction rim thicknesses of the distinct xenocrysts (intercrystalline thickness) are diverse. This implies that the magma could have incorporated discrete orthopyroxene xenocrysts at different times/levels.
In the studied basalts, we determined the change in radius (i.e. the reaction rim thicknesses) of numerous orthopyroxene xenocrysts (0.05–0.48 mm): multiple measurements of the thickness of the same reaction rim were performed on a given crystal and the results were averaged. The reaction rims are frequently overgrown by a phenocrystic clinopyroxene mantle, therefore the orthopyroxene-melt interaction could be stopped much earlier, before the quenching. It is important to note that the dissolution rate of orthopyroxene largely depends on the prevailing conditions, mainly on the pressure. Thus, during magma ascent, the reaction rate can change and the resulting reaction rim thicknesses may preserve a derivative time of interaction.
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Jankovics, M.É., Dobosi, G., Embey-Isztin, A. et al. Origin and ascent history of unusually crystal-rich alkaline basaltic magmas from the western Pannonian Basin. Bull Volcanol 75, 749 (2013). https://doi.org/10.1007/s00445-013-0749-7
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DOI: https://doi.org/10.1007/s00445-013-0749-7