Abstract
We present a detailed mineralogical and major- and trace-element study of pyroxenes in two Archean komatiitic flows in Alexo, Canada. The pyroxenes in spinifex-textured lavas commonly are zoned with cores of magnesian pigeonite and rims of augite. Concentrations of incompatible trace elements are low in pigeonite and jump to higher values in the augite mantles, a variation that can be modelled using accepted partition coefficients and assuming crystallization from komatiitic liquids. Crystallization sequences are very different in different parts of both flows. In the flow top, the sequence is olivine followed by augite: deeper in the spinifex sequence, pigeonite crystallizes after olivine, followed by augite; in lower cumulates, orthopyroxene or augite accompany olivine. In spinifex lavas, pigeonite crystallizes sooner than would be predicted on the basis of equilibrium phase relations. We propose that contrasting crystallization sequences depend on the position in the flow and on the conditions of crystal growth. In the flowtop, rapid cooling causes quench crystallization. Deeper in the spinifex layer, constrained growth in a thermal gradient, perhaps augmented by Soret differentiation, accounts for the early crystallization of pigeonite. The cumulus minerals represent a near-equilibrium assemblage. Augites in Al-undepleted Archean komatiites in various localities in Canada and Zimbabwe have high moderate to high Wo contents but their Mg# (Mg/(Mg + Fe) are lower than in augites in komatiites from Barberton, South Africa. We attribute the combination of high Wo and high Mg# in Barberton rocks to the unusually high CaO/Al2O3 of these Al-depleted komatiites.
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References
Arndt NT (1976) Melting relations of ultramafic lavas (komatiites) at 1 atm and high pressure. Carnegie Institution Washington. Yearbook, vol 75. Carnegie Institution, Washington, pp 555–562
Arndt NT (1977) Thick, layered peridotite-gabbro lava flows in Munro Township, Ontario. Can J Earth Sci 14:2620–2637. doi:10.1139/e77-227
Arndt NT (1982) Proterozoic spinifex-textured basalts of Gilmour Island, Hudson Bay. Geol Surv Can Paper 83-1A:137–142
Arndt NT (1986) Differentiation of komatiite flows. J Petrol 27:279–301
Arndt NT, Fleet ME (1979) Stable and metastable pyroxene crystallization in layered komatiite flows. Am Mineral 64:856–864
Arndt NT, Nesbitt RW (1982) Geochemistry of Munro Township basalts. In: Arndt NT, Nisbet EG (eds) Komatiites. George Allen and Unwin, London, pp 309–330
Arndt NT, Barnes ST, Lesher CM (2008) Komatiite. Cambridge University Press, London, p 478
Ayer JA, Corfu F, Kamo SL, Ketchum J, Kwok K, Trowell N (2002) Evolution of the southern Abitibi greenstone belt based on U–Pb geochronology: autothonous volcanic construction followed by plutonism, regional deformation and sedimentation. Precambrian Res 115:63–95. doi:10.1016/S0301-9268(02)00006-2
Barnes S-J (1983) A comparative study of olivine and clinopyroxene spinifex flows from Alexo, Abitibi greenstone belt, Canada. Contrib Mineral Petrol 83:293–308. doi:10.1007/BF00371198
Bickle MJ, Arndt NT, Nisbet EG, Orpen JL, Martin A, Keays RR, Renner R (1993) Geochemistry of the igneous rocks of the Belingwe greenstone belt: alteration, contamination and petrogenesis. In: Bickle MJ, Nisbet EG (eds) The geology of the Belingwe Greenstone Belt, Zimbabwe. Balkema, Rotterdam, pp 175–214
Campbell IH, Arndt NT (1982) Pyroxene accumulation in spinifex-textured rocks. Geol Mag 119:605–610
Dann JC (2000) The Komati Formation, Barberton Greenstone Belt, South Africa, part I: new map and magmatic architecture. S Afr J Earth Sci 6:681–730
Dann JC (2001) Vesicular komatiites, 3.5-Ga Komati Formation, Barberton Greenstone Belt, South Africa: inflation of submarine lavas and origin of spinifex zones. Bull Volcanol 63:462–481. doi:10.1007/s004450100164
Donaldson CH (1982) Spinifex-textured komatiites: a review of textures, mineral compositions, and layering. In: Arndt NT, Nisbet EG (eds) Komatiites. Allen and Unwin, London, pp 211–244
Dupré B, Chauvel C, Arndt NT (1984) Pb and Nd isotopic study of two Archean komatiitic flows from Alexo, Ontario. Geochim Cosmochim Acta 48:1965–1972. doi:10.1016/0016-7037(84)90378-8
Faure F, Schiano P (2005) Experimental investigation of equilibration conditions during forsterite growth and melt inclusion formation. Earth Planet Sci Lett 236(3–4):882–898. doi:10.1016/j.epsl.2005.04.050
Faure F, Arndt N, Libourel G (2006) Formation of spinifex texture in komatiites: an experimental study. J Petrol 47(8):1591–1610. doi:10.1093/petrology/egl021
Fleet ME, MacRae ND (1975) A spinifex rock from Munro Township, Ontario. J Can Earth Sci 12:928–939
Grove TL, Parman S (2004) Thermal evolution of the Earth as recorded by komatiites. Earth Planet Sci Lett 219:173–187. doi:10.1016/S0012-821X(04)00002-0
Grove TL, de Wit MJ, Dann J (1997) Komatiites from the Komati Type Section, Barberton, South Africa. In: de Wit MJ, Ashwal LD (eds) Greenstone belts. Oxford Science Publications, Oxford, pp 422–437
Grove TL, Parman SW, Dann JC (1999) Conditions of magma generation for Archean komatiites from the Barberton Mountainland, South Africa. In: Fei Y, Bertka CM, Mysen BO (eds) Mantle petrology: field observations and high-pressure experimentation. The Geochemical Society, Houston, pp 155–167
Hart SR, Dunn T (1993) Experimental Cpx melt partitioning of 24 trace-elements. Contrib Mineral Petrol 113(1):1–8. doi:10.1007/BF00320827
Hellebrand E, Snow JE, Hoppe P, Hofmann AW (2002) Garnet-field melting and late-stage refertilization in ‘residual’ abyssal peridotites from the Central Indian Ridge. J Petrol 43(12):2305–2338. doi:10.1093/petrology/43.12.2305
Herd CDK, Treiman AH, McKay GA, Shearer CK (2004) The behavior of Li and B during planetary basalt crystallization. Am Mineral 89(5–6):832–840
Jochum KP, Dingwell DB, Rocholl A, Stoll B, Hofmann A, Becker S, Besmehn A, Besesette D, Dietze H-J, Dulski P, Erzinger J, Hellebrand E, Hoppe P, Horn I, Janssens K, Jenner G, Klein M, McDonough WM, Maetz M, Mezger K, Münker C, Nikogosian IK, Pickhart C, Raczek I, Rhede D, Seufert HM, Simakin SG, Sobolev AV, Spettel B, Straub S, Vincze L, Wallianos A, Weckwerth G, Weyer S, Wolf D, Zimmer M (2000) The preparation and preliminary characterisation of eight geological MPI-DING reference glasses for in situ microanalysis. Geostand Newsl 24:87–133. doi:10.1111/j.1751-908X.2000.tb00590.x
Jolly WT (1982) Progressive metamorphism of komatiites and related Archaean lavas of the Abitibi area, Canada. In: Arndt NT, Nisbet EG (eds) Komatiites. George Allen and Unwin, London, pp 245–266
Kinzler RJ, Grove TL (1985) Crystallization and differentiation of Archean komatiite lavas from northeast Ontario: phase equilibrium and kinetic studies. Am Mineral 70:40–51
Lahaye Y, Arndt NT (1996) Alteration of a komatiitic flow: Alexo, Ontario, Canada. J Petrol 37:1261–1284. doi:10.1093/petrology/37.6.1261
LaTourrette T, Wasserburg GJ, Fahey AJ (1996) Self diffusion of Mg, Ca, Ba, Nd, Yb, Ti, Zr, and U in haplobasaltic melt. Geochim Cosmochim Acta 60(8):1329–1340. doi:10.1016/0016-7037(96)00015-4
Latypov RM (2003) The origin of marginal compositional reversals in basic-ultrabasic sills and layered intrusions by soret fractionation. J Petrol 44(9):1579–1618. doi:10.1093/petrology/egg050
Lesher CE, Walker D (1988) Cumulate maturation and melt migration in a temperature gradient. J Geophys Res 93:10295–10311. doi:10.1029/JB093iB09p10295
Lesher CE, Walker D (1991) Thermal diffusion in petrology. In: Ganguly J (ed) Diffusion, atomic ordering, and mass transport; selected topics in geochemistry. Springer, New York, pp 396–451
Lofgren GE, Donaldson CH (1975) Curved branching crystals and differentiation in comb-layered rocks. Contrib Mineral Petrol 274:243–273
McDonough WF, Danyushevsky LV (1995) Water and sulfur contents of melt inclusions from Archean komatiites. EOS 76:266
Naldrett AJ, Mason GD (1968) Contrasting Archaean ultramafic igneous bodies in Dundonald and Clerque Townships, Ontario. J Can Earth Sci 5:111–143
Nisbet EG (1982) The tectonic setting and petrogenesis of komatiites. In: Arndt NT, Nisbet EG (eds) Komatiites. George Allen and Unwin, London, pp 501–520
Nisbet EG, Arndt NT, Bickle MJ, Cameron WE, Chauvel C, Cheadle M, Hegner E, Kyser TK, Martin A, Renner R, Roedder E (1987) Uniquely fresh 2.7 Ga komatiites from the Belingwe greenstone belt, Zimbabwe. Geology 15:1147–1150. doi:10.1130/0091-7613(1987)15<1147:UFGKFT>2.0.CO;2
Parman S, Dann J, Grove TL, de Wit MJ (1997) Emplacement conditions of komatiite magmas from the 3.49 Ga Komati Formation, Barberton Greenstone Belt, South Africa. Earth Planet Sci Lett 150:303–323. doi:10.1016/S0012-821X(97)00104-0
Parman S, Grove TL, Dann J (2001) The production of Barberton komatiites in an Archean subduction zone. Geophys Res Lett 28:2513–2516. doi:10.1029/2000GL012713
Parman SW, Shimizu N, Grove TL (2003) Constraints on the pre-metamorphic trace element composition of Barberton komatiites from ion probe analyses of preserved clinopyroxene. Contrib Mineral Petrol 144:383–396
Parman S, Grove TL, Dann J, de Wit MJ (2004) A subduction origin for komatiites and cratonic lithospheric mantle. S Afr J Geol 107:107–118. doi:10.2113/107.1-2.107
Pyke DR, Naldrett AJ, Eckstrand OR (1973) Archean ultramafic flows in Munro Township, Ontario. Geol Soc Am Bull 84:955–978. doi:10.1130/0016-7606(1973)84<955:AUFIMT>2.0.CO;2
Schott J (1983) Thermal diffusion and magmatic differentiation: a new look at an old problem. Bull Mineralogy 106:247–262
Schwandt CS, McKay GA (1998) Rare earth element partition coefficients from enstatite/melt synthesis experiments. Geochim Cosmochim Acta 62:2845–2848. doi:10.1016/S0016-7037(98)00233-6
Shaw DM (1970) Trace element fractionation during anatexis. Geochim Cosmochim Acta 34:237–243
Shimizu KT, Komiya S, Maruyama S, Hirose K (2001) Water content of melt inclusion in Cr-spinel of 2.7 Ga komatiite from Belingwe Greenstone Belt, Zimbabwe. Earth Planet Sci Lett 78:750
Shimizu K, Nakamura E, Maruyama S (2005) The geochemistry of ultramafic to mafic volcanics from the Belingwe Greenstone Belt, Zimbabwe: magmatism in an Archean continental large igneous province. J Petrol 46(11):2367–2394. doi:10.1093/petrology/egi059
Shore M, Fowler AD (1999) The origin of spinifex texture in komatiites. Nature 397(6721):691–694. doi:10.1038/17794
Sobolev AV, Migdisov AA, Portnyagin MV (1996) Incompatible element partitioning between clinopyroxene and basalt liquid revealed by the study of melt inclusions in minerals from Troodos lavas, Cyprus. Petrology 4(3):307–317
Stone WE, Jensen LS, Church WR (1987) Petrography and geochemistry of an unusual Fe-rich basaltic komatiite from Boston Township, northeastern Ontario. Can J Earth Sci 24:2537–2550
Turner JS, Huppert HE, Sparks RSJ (1986) Komatiites II: experimental and theoretical investigations of post-emplacement cooling and crystallization. J Petrol 27:397–437
Walker D, Jurewicz S, Watson EB (1988) Adcumulus dunite growth in a laboratory thermal gradient. Contrib Mineral Petrol 99(3):306–319
Wilson AH (2003) A new class of silica enriched, highly depleted komatiites in the southern Kaapvaal Craton, South Africa. Precambrian Res 127:125–141. doi:10.1016/S0301-9268(03)00184-0
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Bouquain, S., Arndt, N.T., Hellebrand, E. et al. Crystallochemistry and origin of pyroxenes in komatiites. Contrib Mineral Petrol 158, 599–617 (2009). https://doi.org/10.1007/s00410-009-0399-0
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DOI: https://doi.org/10.1007/s00410-009-0399-0