Hostname: page-component-7bb8b95d7b-2h6rp Total loading time: 0 Render date: 2024-09-12T18:48:48.734Z Has data issue: false hasContentIssue false
  • English
  • Français

The role of magmatic reaction, diffusion and annealing in the evolution of coronitic microstructure in troctolitic gabbro from Risör, Norway

Published online by Cambridge University Press:  05 July 2018

Raymond Joesten
Raymond Joesten*
Affiliation:
Department of Geology and Geophysics, The University of Connecticut, Storrs, CT 06268 USA
Get access Rights & Permissions [Opens in a new window]

Abstract

Coronas of symplectic pargasite [XMg = 68, XCa = 69, XSi = 68] + spinel [SP45] and orthopyroxene [EN70] separate cumulus plagioclase [AN64] and olivine [FO64] in troctolitic gabbro from Risör, Norway. Coronas with a primary microstructure characterized by low-angle grain boundaries have the mineral assemblage layer sequence,

PLAGIOCLASE : PARGASITE + SPINEL : ORTHOPYROXENE + SPINEL : ORTHOPYROXENE : OLIVINE, whereas those with an annealed microstructure have the layer sequence,

PLAGIOCLASE : PARGASITE + SPINEL : PARGASITE : ORTHOPYROXENE : OLIVINE.

Primary symplectite consists of fan-shaped grains of pargasite that open toward plagioclase and are ribbed by rods of spinel. On annealing to a single grain, low-angle grain boundaries disappear and spinel rods rotate into parallel positions. Primary orthopyroxene, initially radial to layer contacts, anneals to a single grain, rimming olivine. Irregular discontinuous layers and plumes of symplectic orthopyroxene+spinel disappear on annealing and a monomineralic layer of pargasite forms between orthopyroxene and the amphibole symplectite.

The identity of composition of intercumulus pargasite and orthopyroxene with the same phases in primary coronas, the occurrence of primary and annealed coronas rimming cumulus ilmenite and the occurrence of radial orthopyroxene separating grains of cumulus olivine and separating cumulus olivine and plagioclase argue for the origin of primary coronas by fractional crystallization of spinel-saturated troctolitic magma at a pressure greater than 5 kbar.

Irreversible thermodynamic calculations show that the mineral assemblage layer sequence of the primary coronas is diffusionally unstable and that this instability provides the driving force for their spontaneous transformation to the stable mineral assemblage layer sequence of the annealed coronas.

Keywords

magmatismdiffusionannealingcoronasgabbroRisörNorway
Type
Rates of Metamorphic Reactions
Information
Mineralogical Magazine , Volume 50 , Issue 357 , September 1986 , pp. 441 - 467
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1986

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Berg, J.H. (1977) Regional geobarometry in the contact aureoles of the anorthositic Nain complex, Labrador. J. Petrol. 18, 399-430.CrossRefGoogle Scholar
Berg, J.H. (1980) Snowfiake troctolite in the Hettash intrusion: evidence for magma mixing and supercooling in a plutonic environment. Contrib. Mineral. Petrol. 72, 339-51.CrossRefGoogle Scholar
Brogger, W.C. (1934) On several Archaean rocks from the south coast of Norway II. The south Norwegian hyperites and their metamorphism. Skrifter utgitt av Det Norske Videnskaps-Akademi i Oslo,I. Matem.- Naturvid Klasse, 421 pp.Google Scholar
Droop, G.T.P., and Charnley, N.R. (1985) Comparative geobarometry of peletic hornfelses associated with the Newer Gabbros: a preliminary study. J. Geol. Soc. London. 142, 53-62.CrossRefGoogle Scholar
Fisher, G.W. (1973) Nonequilibrium thermodynamics as a model for diffusion-controlled metamorphic processes. Am. J. Sci. 273, 897-924.CrossRefGoogle Scholar
Fisher, G.W. (1977) Nonequilibrium thermodynamics in metamorphism. In Thermodynamics in Geolog.(D. Fraser, ed.). D. Reidel, Dordrecht, pp. 381–403.CrossRefGoogle Scholar
Frantz, J.D., and Mao, H.K. (1975) Bimetasomatism resulting from intergranular diffusion: multimineralic zone sequences. Carnegie Inst. Wash. Yearb. 74, 417-24.Google Scholar
Gresens, R.L. (1967) Composition-volume relationships of metasomatism. Chem. Geo. 2, 47–65.CrossRefGoogle Scholar
Grieve, R.A.F., and Gittins, J. (1975) Composition and formation of coronas in the Haddlington gabbro, Ontario, Canada. Can. J. Earth Sci. 12, 289-99.CrossRefGoogle Scholar
Griffin, W.L., and Heier, K.S. (1973) Petrological implications of some corona structures. Lithos. 6, 315-35.CrossRefGoogle Scholar
Harker, A. (1909) The Natural History of Igneous Rock. Hafner, New York, 384 pp.Google Scholar
Joesten, R. (1977) Evolution of mineral assemblage zoning in diffusion metasomatism. Geochim. Cosmochim. Ad. 41, 649-70.CrossRefGoogle Scholar
Joesten, R. (1978) Diffusion-controlled growth of pyroxenespinel coronas between forsterite and anorthite in the system CaO-MgO-Al2O3-SiO2. Geol. Soc. Am. Abstr. Program. 10, 429.Google Scholar
Kuo, L.-C. and Kirkpatrick, R.J. (1985) Kinetics of crystal dissolution in the system diopside-forsteritesilica. Am. J. Se. 285, 51-90.Google Scholar
Kushiro, I. (1969) The system forsterite-diopside-silica with and without water at high pressures. Am. J. Sc. 267-A, 269-94.Google Scholar
Kushiro, I. (1974) Melting of hydrous upper mantle and possible generation of andesitic magma: an approach from synthetic systems. Earth Planet. Sci. Lett. 22, 294-9.CrossRefGoogle Scholar
Kushiro, I. and Yoder, H.S., Jr. (1966) Anorthite-forsterite and anorthite-enstatite reactions and their bearing on the basalt-eclogite transformation. J. Petrol. 5, 195-218.Google Scholar
Kushiro, I. and Nishikawa, M. (1968) Effect of water on the melting of enstatite. Geol. Soc. Am. Bull. 79, 1685-92.CrossRefGoogle Scholar
Laird, J., and Albee, A.L. (1981) Pressure, temperature and time indicators in mafic schist: their application to reconstructing the polymetamorphic history of Vermont. Am. J. Sci. 281, 127-75.CrossRefGoogle Scholar
McLelland, J.M. and Whitney, P.R. (1977) The origin of garnet in the anorthosite-charnockite suite of the Adirondacks. Contrib. Mineral. Petrol. 60, 161-81.CrossRefGoogle Scholar
McLelland, J.M. and Whitney, P.R. (1980a) A generalized garnet-forming reaction for meta-igneous rocks in the Adirondacks. Ibid. 72, 111-22.CrossRefGoogle Scholar
McLelland, J.M. and Whitney, P.R. (1980b) Compositional controls on spinel clouding and garnet formation in plagiodase of olivine metagabbros, Adirondack Mountains, New York. Ibid. 73, 243-51.CrossRefGoogle Scholar
Mason, R. (1967) Electron-probe microanalysis of coronas in a troctolite from Sulitjelma, Norway. Mineral. Mag. 36, 504-14.Google Scholar
Mason, R. (1971) The chemistry and structure of the Sulitjelma gabbro. Nor. Geol. Unders. 269, 108-42.Google Scholar
Medaris, L.G. (2969) Partitioning of Fe2+ and Mg2 + between coexisting synthetic olivine and orthopyroxene. Am. J. Sci. 267, 945-68.CrossRefGoogle Scholar
Mongkoltip, P., and Ashworth, J.R. (1983) Quantitative estimation of and open-system symplectite-forming reaction: restricted diffusion of Al and Si in coronas around olivine. J. Petrol. 24, 635-61.CrossRefGoogle Scholar
Morse, S.A. (1979a) Kiglapait geochemistry I: Systematics, sampling, and density. Ibid. 20, 555-90.CrossRefGoogle Scholar
Morse, S.A. (1979b) Kiglapait geochemistry II: Petrography. Ibid. 20, 591-624.CrossRefGoogle Scholar
Morse, S.A. (1980) Basalts and Phase Diagram. Springer-Verlag, New York, 493 pp.CrossRefGoogle Scholar
Morse, S.A. (1981) Kiglapait geochemistry IV: The major elements. Geochim. Cosmochim. Acta. 45, 461-79.CrossRefGoogle Scholar
Murthy, M.V.N. (1958) Coronites from India and their bearing on the origin of coronas. Geol. Soc. Am. Bull. 68, 23-38.CrossRefGoogle Scholar
Nishiyama, T. (1983) Steady diffusion model for olivineplagioclase corona growth. Geochim. Cosmochim. Act. 47, 283-94.CrossRefGoogle Scholar
Nockolds, S.R., Knox, R.W. O'B., and Chinner, G.A. (1978) Petrology for Student. Cambridge University Press, Cambridge, 435 pp.Google Scholar
Presnall, D.C. Dixon, S.A., Dixon, J.R., O'Donnell, T.H., Schrock, R.L., and Dycus, D.W. (1978) Liquidus phase relations on the join diopside-forsterite-anorthite from 1 atm to 20 kbar: their bearing on the generation and crystallization of basaltic magma. Contrib. Mineral. Petrol. 66, 203-20.CrossRefGoogle Scholar
Dixon, J.R., O'Donnell, T.H., and Dixon, S.A. (1979) Generation of mid-ocean ridge tholeiites. J. Petrol. 20, 3-36.Google Scholar
Reynolds, R.C. Jr., and Frederickson, A.F. (1962) Corona development in Norwegian hyperites and its bearing on the metamorphic facies concept. Geol. Soc. Am. Bull. 73, 59-72.CrossRefGoogle Scholar
Sederholm, J. (1916) On synantectic minerals and related phenomena. Comm. Geol. Finlande Bull. 48, 1-148.Google Scholar
Starmer, I.C. (1969) Basic plutonic intrusions of the Risor-Sondeled area, south Norway: the original lithologies and their metamorphism. Norsk Geol. Tidss. 49, 403-31.Google Scholar
Statham, P.J. (1976) A comparative study of techniques for quantitative analysis of the X-ray spectra obtained with a Si(Li) detector. X-ray Spectrom. 5, 16-28.CrossRefGoogle Scholar
Sweatman, T.R., and Long, J.V.P. (1969) Quantitative electron-probe microanalysis of rock forming minerals. J. Petrol. 16, 332-79.CrossRefGoogle Scholar
Tornebohm, A.E. (1877) Om Sveriges viktigare Diabas- och Gabbro-Arter. Kgl. Sveska Vetenskaps- Akademiens Handlingar,B.14, No. 13.Google Scholar
van Lamoen, H. (1979) Coronas in olivine gabbros and iron ores from Susimake and Riuttamaa, Finland. Contrib. Mineral. Petrol. 68, 259-68.CrossRefGoogle Scholar
Wager, L.R., and Brown, G.M. (1967) Layered Igneous Rock. W. H. Freeman and Co., San Francisco, 588 pp.Google Scholar
Whitney, P.R., and McLelland, J.M. (1973) Origin of coronas in metagabbros of the Adirondack Mts, N.Y. Contrib. Mineral. Petrol. 39, 81-98.CrossRefGoogle Scholar
Wilson, R., Esbensen, K.H., and Thy, P. (1981) Igneous petrology of the synorogenic Fongen-Hyllingen layered basic complex, south-central Scandinavian Caledonides. J. ‘Petrol. 22, 584-627.CrossRefGoogle Scholar