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Phase equilibria testing of a multiple pulse mechanism for origin of mafic–ultramafic intrusions: a case example of the Shiant Isles Main Sill, NW Scotland

Published online by Cambridge University Press:  27 May 2009

RAIS LATYPOV*
Affiliation:
Department of Geosciences, University of Oulu, Oulu, P.O. Box 3000, FI – 90014, Finland
SOFYA CHISTYAKOVA
Affiliation:
Department of Geosciences, University of Oulu, Oulu, P.O. Box 3000, FI – 90014, Finland
*
*Author for correspondence: Rais.Latypov@oulu.fi

Abstract

In this paper we examine the role of multiple emplacement of sills into partly solidified rocks (an intrusive mechanism ‘liquid into solid’) as a possible explanation for some textural and compositional ‘anomalies’ of single-cyclic mafic intrusions. As a case study we used the Shiant Isles Main Sill that is widely regarded as a classical example of a multiple, picrite–picrodolerite–crinanite alkaline sill. This sill is currently interpreted as having been formed by several olivine phenocryst-rich pulses of magma, which were successively emplaced into their almost solidified predecessors. Such an intrusive mechanism is a random process in which many parameters vary independently and unpredictably. Among them are: the number, relative volume and bulk composition of magma pulses, and their place, sequence and timing of emplacement, as well as modal abundance, phase composition and distribution of intratelluric phenocrysts in magmas upon emplacement. In terms of these variables, one can envisage countless different profiles through alkaline sills produced from only three randomly intruded magma pulses of picritic, picrodoleritic and crinanitic composition. Such multiple sills can readily be distinguished from simple ones formed from a single pulse of magma by anomalous compositional profiles with several prominent breaks in crystallization and compositional sequences. The compositional profile of the Shiant Isles Main Sill is remarkably similar to an M-shaped profile expected from fractional crystallization of a single pulse of olivine-saturated magma along a crystallization path Ol+Sp+L (picrite), Ol+Pl±Sp+L (picrodolerite = troctolite), Ol+Pl+Cpx+L (crinanite). The probability of the accidental formation of such a compositional profile by multiple intrusion ‘liquid into solid’ is exceedingly small, even for the single case of the Shiant Isles Main Sill. The probability approaches zero when considering that exactly the same sequence of intrusive events must have been repeated in about 20 neighbouring alkaline sills with similar compositional profiles. This can only be achieved by some universally operating differentiation process. The best candidate for this is the classical fractional crystallization of magma constrained by liquidus phase equilibria. This suggests that the Shiant Isles Main Sill can be best interpreted and modelled as a simple sill that crystallized from one large pulse of magma, with possible involvement of minor refilling events. Further progress in our knowledge of intrachamber magma fractionation processes will probably enable us to interpret many ‘anomalous’ textural and compositional features of mafic–ultramafic intrusions in the frame of a single magma pulse model.

Type
Original Article
Copyright
Copyright © Cambridge University Press 2009

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References

Alapieti, T. T. & Lahtinen, J. J. 2002. Platinum-group element mineralization in layered intrusions of Northern Finland and the Kola Peninsular, Russia. In The Geology, Geochemistry, Mineralogy and Mineral Beneficiation of Platinum-group Elements (ed. Cabri, L. J.), vol. 54, pp. 507–46. Canadian Institute of Mining, Metallurgy and Petroleum.Google Scholar
Ariskin, A. A. & Barmina, G. S. 2000. Modelling of phase equilibria upon crystallization of basalt magmas. Moscow: Nauka, MAIK “Nauka/Interperiodica”, 363 pp. (in Russian).Google Scholar
Arndt, N. T. 2005. The conduits of magmatic ore deposits. In Exploration for platinum-group element deposits (ed. Mungall, J. E.), pp. 181201. Mineralogical Association of Canada, Short Course series 35.Google Scholar
Arndt, N. T., Czamanske, G., Walker, R. J., Chauvel, C. & Fedorenko, V. 2003. Geochemistry and origin of the intrusive hosts of the Noril'sk-Talnakh Cu–Ni–PGE sulfide deposits. Economic Geology 98, 495515.Google Scholar
Bédard, J. H., Sparks, R. S. J., Renner, R., Cheadle, M. J. & Hallworth, M. A. 1988. Peridotite sills and metasomatic gabbros in the Eastern Layered Series of the Rhum Complex. Journal of the Geological Society, London 145, 207–24.CrossRefGoogle Scholar
Czamanske, G. K., Wooden, J. L., Zientek, M. L., Fedorenko, V. A, Zen'ko, T. E., Kent, J., King, B.-S. W., Knight, R. J. & Siems, D. F. 1994. Geochemical and isotopic constraints on the petrogenesis of the Noril'sk–Talnakh ore-forming system. Proceedings of the Sudbury-Noril'sk symposium. Ontario Geological Survey Special Publication 5, 313–42.Google Scholar
Czamanske, G. K., Zen'ko, T. E., Fedorenko, V. A., Calk, L. C., Budahn, J. R., Bullock, J. H. Fries, T. L. Jr, King, B.-S. W. & Siems, D. F. 1995. Petrographic and geochemical characterization of ore-bearing intrusions of the Noril'sk type, Siberia; with discussion of their origin. Resource Geology Special Issue 18, 148.Google Scholar
Desharnais, G., Peck, D. C., Scoates, R. F. J. & Halden, N. M. 2004. The KO zone: a new model for PGE–Cu–Ni mineralization in the marginal zone of the Fox River sill, Northern Manitoba, Canada. Canadian Mineralogist 42, 291302.CrossRefGoogle Scholar
Drever, H. I. 1953. A note on the field relations of the Shiant Isles picrite. Geological Magazine 90, 159–60.CrossRefGoogle Scholar
Drever, H. I. & Johnston, R. 1965. New petrographical data on the Shiant Isles picrite. Mineralogical Magazine 34, 194203.CrossRefGoogle Scholar
Dubrovskii, M. I. 1998. Differentiation Trends of the Standard Alkalinity Olivine-normative Magmas and Corresponding Rock Series. Apatity: Kola Science Center, 336 pp. (in Russian).Google Scholar
Emeleus, C. H., Cheadle, M. J., Hunter, R. H., Upton, B. G. J. & Wadsworth, W. J. 1996. The Rum Layered Suite. In Layered Intrusions (ed. Cawthorn, R. G.), pp. 403–39. Developments in Petrology 15. Elsevier Science B. V.CrossRefGoogle Scholar
Flett, J. S. 1931. The Blackness teschenite. Summary of progress of Geological Survey of Great Britain 3, 3945.Google Scholar
Foland, K. A., Gibb, F. G. F. & Henderson, C. M. B. 2000. Patterns of Nd and Sr isotopic ratios produced by magmatic and postmagmatic processes in the Shiant Isles Main Sill, Scotland. Contributions to Mineralogy and Petrology 139, 655–71.CrossRefGoogle Scholar
Frenkel’, M. Ya., Yaroshevsky, A. A., Ariskin, A. A., Barmina, G. S., Koptev-Dvornikov, E. V. & Kireev, B. S. 1988. Dynamics of in situ differentiation of mafic magmas. Moscow: Nauka, 216 pp. (in Russian).Google Scholar
Frenkel’, M. Ya., Yaroshevsky, A. A., Ariskin, A. A., Barmina, G. S., Koptev-Dvornikov, E. V. & Kireev, B. S. 1989. Convective–cumulative model simulating the formation process of stratified intrusions. In Magma–Crust Interactions and Evolution, Theophrastus Publication (eds Bonin, N., Didier, J., Le Fort, P., Propach, G., Puga, E. & Vistelius, A. B.), pp. 388. Athens, Greece.Google Scholar
Gibb, F. G. F. 1973. The zoned clinopyroxenes of the Shiant Isles sill. Journal of Petrology 14, 203–30.CrossRefGoogle Scholar
Gibb, F. G. F. & Gibson, S. A. 1989. The Little Minch Sill Complex. Scottish Journal of Geology 25, 367–70.CrossRefGoogle Scholar
Gibb, F. G. F. & Henderson, C. M. B. 1984. The structure of the Shiant Isles sill complex. Scottish Journal of Geology 20, 21–9.CrossRefGoogle Scholar
Gibb, F. G. F. & Henderson, C. M. B. 1989. Discontinuities between picritic and crinanitic units in the Shiant Isles sill: evidence of multiple intrusion. Geological Magazine 126, 127–37.CrossRefGoogle Scholar
Gibb, F. G. F. & Henderson, C. M. B. 1992. Convection and crystal settling in sills. Contributions to Mineralogy and Petrology 109, 538–45.CrossRefGoogle Scholar
Gibb, F. G. F. & Henderson, C. M. B. 1996. The Shiant Isles main sill: structure and mineral fractionation trends. Mineralogical Magazine 60, 6797.CrossRefGoogle Scholar
Gibb, F. G. F. & Henderson, C. M. B. 2006. Chemistry of the Shiant Isles Main Sill, NW Scotland, and wider application for petrogenesis of mafic sills. Journal of Petrology 47, 191230.CrossRefGoogle Scholar
Gibson, S. A. & Jones, A. P. 1991. Igneous stratigraphy and internal structure of the Little Minch Sill Complex, Trotternish Peninsula, northern Skye, Scotland. Geological Magazine 128, 5166.CrossRefGoogle Scholar
Gisselø, P. G. 2001. Sorgenfri Gletscher Sill Complex, East Greenland: solidification mechanisms of sheet-like bodies and the role of sill complexes in large igneous provinces. Published Ph.D. thesis, University of Aarhus, Denmark. Aarhus Geoscience Vol. 10.Google Scholar
Gunn, B. M. 1966. Modal and element variation in Antarctic tholeiites. Geochimica et Cosmochimica Acta 30, 881920.CrossRefGoogle Scholar
Henderson, C. M. B. & Gibb, F. G. F. 1987. The petrology of the Lugar sill, SW Scotland. Transactions of the Royal Society of Edinburgh (Earth Sciences) 77, 325–47.CrossRefGoogle Scholar
Henderson, C. M. B., Gibb, F. G. F. & Foland, K. A. 2000. Mineral fractionation and pre- and post-emplacement processes in the uppermost part of the Shiant Isles Main Sill. Mineralogical Magazine 64, 779–90.CrossRefGoogle Scholar
Holness, M. B. & Winpenny, B. 2009. The Unit 12 allivalite, Eastern Layered Intrusion, Isle of Rum: a textural and geochemical study of an open-system magma chamber. Geological Magazine 146, 437–50.CrossRefGoogle Scholar
Hoshide, T., Obata, M. & Akatsuka, T. 2006. Crystal settling and crystal growth of olivine in magmatic differentiation – the Murotomisaki gabbroic complex, Shikotu, Japan. Journal of Mineralogical and Petrological Sciences 101, 223–39.CrossRefGoogle Scholar
Huppert, H. E. & Sparks, R. S. J. 1989. Chilled margins in igneous rocks. Earth and Planetary Science Letters 92, 397405.CrossRefGoogle Scholar
Jaupart, C. & Tait, S. 1995. Dynamic of differentiation in magma reservoirs. Journal of Geophysical Research 100, 17617–36.CrossRefGoogle Scholar
Johnston, R. 1953. The olivines of the Garbh Eilean sill, Shiant Isles. Geological Magazine 90, 161–71.CrossRefGoogle Scholar
Irvine, T. N. 1970. Crystallization sequences in the Muskox intrusion and other layered intrusions, I. Olivine–pyroxene–plagioclase relations. Special Publication of Geological Society of South Africa 1, 441–76.Google Scholar
Koptev-Dvornikov, E. V., Kireev, B. S., Pchelintseva, N. F. & Khvorov, D. M. 2001. Distribution of cumulative mineral assemblages, major and trace elements over the vertical section of the Kivakka intrusion, Olanga group of intrusions, Northern Karelia. Petrology 9, 124.Google Scholar
Krivolutskaya, N. A., Ariskin, A. A., Sluzhenikin, S. F. & Turovtsev, D. M. 2001. Geochemical thermometry of the Talnakh intrusion: assessment of the melt composition and the crystallinity of the parental magma. Petrology 9, 451–79.Google Scholar
Latypov, R. M. 2003 a. The origin of marginal compositional reversals in basic–ultrabasic sills and layered intrusions by Soret fractionation. Journal of Petrology 44, 15791618.CrossRefGoogle Scholar
Latypov, R. M. 2003 b. The origin of basic–ultrabasic sills with S-, D- and I-shaped compositional profiles by in situ crystallization of a single input of phenocryst-poor parental magma. Journal of Petrology 44, 1619–56.CrossRefGoogle Scholar
Latypov, R. M. 2009. Testing the validity of the petrological hypothesis “no phenocrysts, no post-emplacement differentiation”. Journal of Petrology, in press.CrossRefGoogle Scholar
Latypov, R. M. & Alapieti, T. T. 2003. The role of Soret fractionation in the origin of compositional profiles in mafic–ultramafic sills: implication to ore-bearing intrusions of the Noril'sk type, Siberia. In Mineral Exploration and Sustainable Development (eds Eliopoulos, D. G. et al. ), pp. 607–10. Rotterdam: Millpress.Google Scholar
Latypov, R. M., Chistyakova, S. Yu. & Alapieti, T. T. 2007. Revisiting problem of chilled margins associated with marginal reversals in mafic–ultramafic intrusive bodies. Lithos 99, 178206.CrossRefGoogle Scholar
Li, C., Ripley, E. M. & Naldrett, A. J. 2003. Compositional variations of olivine and sulfur isotopes in the Noril'sk and Talnakh intrusions, Siberia: implications for ore-forming processes in dynamic magma conduits. Economic Geology 98, 6986.Google Scholar
Marsh, B. D. 1996. Solidification fronts and magmatic evolution. Mineralogical Magazine 60, 540.CrossRefGoogle Scholar
Marsh, B. D. 2006. Dynamics of magmatic systems. Elements 2, 287–92.CrossRefGoogle Scholar
Mcbirney, A. R. 1996. The Skaergaard intrusion. In Layered Intrusions (ed. Cawthorn, R. G.), pp. 147–80. Developments in Petrology 15. Elsevier Science B. V.CrossRefGoogle Scholar
Morse, S. A. 1969. The Kiglapait layered intrusion, Labrador. Geological Society Memoir 112, 204 pp.Google Scholar
Morse, S. A. 1983. Strontium isotope fractionation in the Kiglapait intrusion. Science 220, 193–5.CrossRefGoogle ScholarPubMed
Morse, S. A. 1986. Convection in aid of adcumulus growth. Journal of Petrology 27, 11831214.CrossRefGoogle Scholar
Morse, S. A. 1988. Motion of crystals, solute, and heat in layered intrusions. Canadian Mineralogist 26, 209–44.Google Scholar
Morse, S. A. 2008. The internal magma reservoir of large intrusions revealed by multiphase Rayleigh fractionation. Journal of Petrology 49, 2081–98.CrossRefGoogle Scholar
Murray, R. J. 1954. The clinopyroxenes of the Garbh Eilean sill, Shiant Isles. Geological Magazine 91, 1731.CrossRefGoogle Scholar
Naldrett, A. J. 1989. Stratiform PGE deposits in layered intrusions. Reviews in Economic Geology 4, 135–66.Google Scholar
Naslund, H. R. 1989. Petrology of the Basistoppen Sill, East Greenland: a calculated magma differentiation trend. Journal of Petrology 30, 299319.CrossRefGoogle Scholar
Peck, D. C., Scoates, R. F. J., Theyer, P., Desharnais, G., Hulbert, L. J. & Huminicki, M. A. E. 2002. Stratiform and contact-type PGE–Cu–Ni mineralization in the Fox River Sill and the Bird River Belt, Manitoba. In The Geology, Geochemistry, Mineralogy and Mineral Beneficiation of Platinum-group Elements, vol. 54 (ed. Cabri, L. J.), pp. 367–87. Canadian Institute of Mining, Metallurgy and Petroleum.Google Scholar
Renner, R. & Palacz, Z. A. 1987. Basaltic replenishment of the Rhum magma chamber: evidence from unit 14. Journal of the Geological Society, London 144, 961–70.CrossRefGoogle Scholar
Rogover, G. B. 1959. Noril'sk I deposit. Moscow: Gosgeoltechizdat, 168 pp. (in Russian).Google Scholar
Simkin, T. 1967. Flow differentiation in the picritic sills of north Skye. In Ultramafic and related rocks (ed. Wyllie, P. J.), pp. 64–9. New York, London, Sydney: John Wiley and Sons.Google Scholar
Smirnov, M. F. 1966. The structure of Noril'sk nickel-bearing intrusions and sulphide ores. Moscow: Nedra, 58 pp. (in Russian).Google Scholar
Sparks, R. S., Huppert, H. E., Koyaguchi, T. & Hallworth, M. A. 1993. Origin of modal and rhythmic igneous layering by sedimentation in a convecting magma chamber. Nature 361, 246–9.CrossRefGoogle Scholar
Tait, S. & Jaupart, C. 1996. The producing of chemically stratified and adcumulate plutonic igneous rocks. Mineralogical Magazine 60, 99114.CrossRefGoogle Scholar
Turovtsev, D. M., Sluzhenikin, S. F. & Distler, V. V. 2000. Petrology of basic–ultrabasic layered massifs of the North Siberia and Southern Taimyr in connection with their PGE potentiality. Petrography on the verge of the XXI century (results and perspectives). Proceedings of the Second All-Russia Petrographic Meeting. Syktyvkar: Institute of Geology Komi, SC UD RAS, 4, 309–13 (in Russian).Google Scholar
Wager, L. R. & Brown, G. M. 1968. Layered Igneous Rocks. Edinburgh and London: Oliver and Boyd, 588 pp.Google Scholar
Walker, F. 1930. The geology of the Shiant Isles (Hebrides). Quarterly Journal of the Geological Society of London 86, 355–98.CrossRefGoogle Scholar
Zieg, M. J. & Marsh, B. D. 2005. The Sudbury Igneous Complex: viscous emulsion differentiation of a superheated impact melt sheet. Geological Society of America Bulletin 117, 1427–50.CrossRefGoogle Scholar