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Crystallization and textural evolution of a closed-system magma chamber: insights from a crystal size distribution study of the Lilloise layered intrusion, East Greenland

Published online by Cambridge University Press:  08 March 2010

C. MAGEE*
Affiliation:
School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
B. O'DRISCOLL
Affiliation:
School of Physical and Geographical Sciences, Keele University, Keele, UK
A. D. CHAMBERS
Affiliation:
School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
*
Author for correspondence: cxm477@bham.ac.uk

Abstract

The recognition that postcumulus processes significantly modify primary textures in layered mafic intrusions has thrown into question many early observations on which classical crystallization theories are based. Petrographic observations combined with quantitative textural analysis of samples from various stratigraphic levels of the Lilloise intrusion, East Greenland, demonstrate that postcumulus textural modification of cumulates, formed during the solidification of a closed system magma chamber, may be detected. Crystal size distribution (CSD) measurements of Lilloise cumulates and the resulting CSD profiles are compared to predicted theoretical closed system CSD profiles. Similarities between the measured CSD profiles and published predicted CSD profiles support Lilloise magma evolving in a closed system chamber and indicate that primary crystallization processes can be distinguished using quantitative textural techniques. Textural coarsening driven by syn-magmatic deformation is suggested to be the dominant postcumulus process affecting CSD plot morphology. CSD slope values and profiles (plot shapes) remain relatively constant for a given liquidus mineral (particularly olivine and clinopyroxene), so that the number of phases on the liquidus at any one time affects mineral modal abundances. As a result, CSDs generally exhibit overall smaller grainsizes and progressively lower nucleation densities at higher levels in the intrusion.

Type
Original Article
Copyright
Copyright © Cambridge University Press 2010

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References

Ashworth, J. R. & Chambers, A. D. 2000. Symplectic reaction in olivine and the controls of intergrowth spacing in symplectites. Journal of Petrology 41, 285304.CrossRefGoogle Scholar
Boorman, S., Boudreau, A. & Kruger, F. J. 2004. The lower zone-critical zone transition of the Bushveld Complex: a quantitative textural study. Journal of Petrology 45, 1209–35.CrossRefGoogle Scholar
Brown, P. E. 1973. A layered plutonic complex of alkali basalt parentage: the Lilloise intrusion, east Greenland. Journal of the Geological Society. London 129, 405–18.CrossRefGoogle Scholar
Brown, P. E., Chambers, A. D. & Becker, S. M. 1987. A large soft-sediment fold in the Lilloise intrusion, East Greenland. In Origins of Igneous Layering (ed. Parsons, I.), pp. 125–43. Dordrecht: D. Reidel.CrossRefGoogle Scholar
Brown, P. E., Tocher, F. E. & Chambers, A. D. 1982. Amphiboles in the Lilloise intrusion, East Greenland. Mineralogical Magazine 45, 4754.CrossRefGoogle Scholar
Chambers, A. D. & Brown, P. E. 1995. The Lilloise intrusion, East Greenland: fractionation of a hydrous alkali picritic magma. Journal of Petrology 36, 933–63.CrossRefGoogle Scholar
Higgins, M. D. 1998. Origin of anorthosite by textural coarsening: Quantitative textural measurements of a natural sequence of textural development. Journal of Petrology 39, 1307–25.CrossRefGoogle Scholar
Higgins, M. D. 2000. Measurement of crystal size distributions. American Mineralogist 85, 1105–16.CrossRefGoogle Scholar
Higgins, M. D. 2002 a. A crystal size-distribution study of the Kiglapait layered mafic intrusion, Labrador, Canada: evidence for textural coarsening. Contributions to Mineralogy and Petrology 144, 314–30.CrossRefGoogle Scholar
Higgins, M. D. 2002 b. Closure in crystal size distributions (CSD), verification of CSD calculations, and the significance of CSD fans. American Mineralogist 87, 171–5.CrossRefGoogle Scholar
Higgins, M. D. 2006 a. Quantitative textural measurements in igneous and metamorphic petrology, 1st ed. Cambridge: Cambridge University Press, 270 pp.CrossRefGoogle Scholar
Higgins, M. D. 2006 b. Verification of ideal semi-logarithmic, lognormal or fractal crystal size distributions from 2D datasets. Journal of Volcanology and Geothermal Research 154, 816.CrossRefGoogle Scholar
Higgins, M. D. 2009. The Cascadia megathrust earthquake in 1700 may have rejuvenated and isolated basalt volcano in western Canada: Age and petrographic evidence. Journal of Volcanology and Geothermal Research 179, 149–56.CrossRefGoogle Scholar
Holness, M. B., Morse, S. A. & Tegner, C. 2009. Response to comment by McBirney, Boudreau & Marsh. Journal of Petrology 50, 97102.CrossRefGoogle Scholar
Holness, M. B., Nielsen, T. F. D. & Tegner, C. 2007. Textural maturity of cumulates: a record of chamber filling, liquidus assemblage, cooling rate and large-scale convection in mafic layered intrusions. Journal of Petrology 48, 141–57.CrossRefGoogle Scholar
Holness, M. B., Tegner, C., Nielsen, T. F. D., Stripp, G. & Morse, S. A. 2007. A textural record of solidification and cooling in the Skaergaard intrusion, East Greenland. Journal of Petrology 48, 2359–77.CrossRefGoogle Scholar
Housden, J., O'Reilly, W. & Day, S. J. 1996. Variations in magnetic properties of Unit 10, Eastern Layered Intrusion, Isle of Rum, Scotland: implications for patterns of high temperature hydrothermal alteration. Transactions of the Royal Society of Edinburgh. Earth Sciences 86, 91112.CrossRefGoogle Scholar
Hunter, R. H. & Sparks, R. S. J. 1987. The differentiation of the Skaergaard intrusion. Contributions to Mineralogy and Petrology 95, 451–61.CrossRefGoogle Scholar
Irvine, T. N. 1982. Terminology for layered intrusions. Journal of Petrology 23, 127–62.CrossRefGoogle Scholar
Jolley, D. W. & Bell, B. R. 2002. The evolution of the North Atlantic Igneous Province and the opening of the NE Atlantic rift. In The North Atlantic Igneous Province: Stratigraphy, Tectonic, Volcanic and Magmatic Processes (eds Jolley, D. W. & Bell, B. R.), pp. 113. Geological Society of London, Special Publication no. 197.Google Scholar
Marsh, B. D. 1988. Crystal size distribution (CSD) in rocks and the kinetics and dynamics of crystallisation I: Theory. Contributions to Mineralogy and Petrology 99, 277–91.CrossRefGoogle Scholar
Marsh, B. D. 1998. On the interpretation of crystal size distributions in magmatic systems. Journal of Petrology 39, 553–99.CrossRefGoogle Scholar
Matthews, D. W. 1976. Postcumulus disruption of the Lilloise intrusion, East Greenland. Geological Magazine 113, 287–95.CrossRefGoogle Scholar
McBirney, A. R. 1975. Differentiation of the Skaergaard intrusion. Nature 253, 691–4.CrossRefGoogle Scholar
McBirney, A. R. 1995. Mechanisms of differentiation in the Skaergaard intrusion. Journal of the Geological Society, London 152, 421–35.CrossRefGoogle Scholar
McBirney, A. R. 2009. Factors governing the textural development of Skaergaard gabbros: A review. Lithos 111, 15.CrossRefGoogle Scholar
McBirney, A. R., Boudreau, A. E. & Marsh, B. D. 2009. Comments on: ‘Textural maturity of cumulates: a record of chamber filling, Liquidus assemblage, cooling rate, and large-scale convection in mafic layered intrusions’ and ‘A textural record of solidification and cooling in the Skaergaard intrusion, East Greenland. Journal of Petrology 50, 93–5.CrossRefGoogle Scholar
McBirney, A. R. & Naslund, H. R. 1990. The differentiation of the Skaergaard Intrusion: a discussion of Hunter and Sparks (Contributions to Mineralogy and Petrology 95, 451–61). Contributions to Mineralogy and Petrology 104, 235–40.CrossRefGoogle Scholar
McBirney, A. R. & Noyes, R. M. 1979. Crystallisation and layering of the Skaergaard intrusion. Journal of Petrology 20, 487554.CrossRefGoogle Scholar
Mock, A., Jerram, D. A. & Breitkreuz, C. 2003. Using Quantitative Textural Analysis to Understand the Emplacement of Shallow-Level Rhyolitic Laccoliths – a Case Study from the Halle Volcanic Complex, Germany. Journal of Petrology 44, 833–49.CrossRefGoogle Scholar
Morgan, D. J. & Jerram, D. A. 2006. On estimating crystal shape for crystal size distribution analysis. Journal of Volcanology and Geothermal Research 154, 17.CrossRefGoogle Scholar
O'Driscoll, B., Donaldson, C. H., Daly, J. S. & Emeleus, C.H. 2009. The roles of melt infiltration and cumulate assimilation in the formation of anorthosite and a Cr-spinel seam in the Rum Eastern Layered Intrusion, NW Scotland. Lithos 111, 620.CrossRefGoogle Scholar
O'Driscoll, B., Donaldson, C. H., Troll, V. R., Jerram, D. A. & Emeleus, C. H. 2007. An origin for harrisitic and granular olivine in the Rum Layered Suite, NW Scotland: a crystal size distribution study. Journal of Petrology 48, 253–70.CrossRefGoogle Scholar
O'Driscoll, B., Stevenson, C. T. E. & Troll, V. R. 2008. Mineral lamination development in layered gabbros of the British Palaeogene Igneous Province: A combined anisotropy of magnetic susceptibility, quantitative textural and mineral chemistry study. Journal of Petrology 49, 11871221.CrossRefGoogle Scholar
Randolph, A. D. & Larsen, M. A. 1971. Theory of particulate processes. New York: Academic Press, 251 pp.Google Scholar
Saunders, A. D., Fitton, J. G., Kerr, A. C., Norry, M. J. & Kent, R. W. 1997. The North Atlantic Igneous Province. Geophysical Monograph 100, 4593.Google Scholar
Tegner, C., Brooks, C. K., Duncan, R. A., Heister, L. E. & Bernstein, S. 2008. 40Ar–39Ar ages of intrusions in East Greenland: Rift-to-drift transition over the Iceland hotspot. Lithos 101, 480500.CrossRefGoogle Scholar
Tegner, C., Duncan, R. A., Bernstein, S., Brooks, C. K., Bird, D. K. & Storey, M. 1998. 40Ar–39Ar geochronology of Tertiary mafic intrusions along the East Greenland rifted margin: Relation to flood basalts and the Iceland hotspot track. Earth and Planetary Science Letters 156, 7588.CrossRefGoogle Scholar
Tegner, C., Thy, P., Holness, M. B., Jakobsen, J. K. & Lesher, C. E. 2009. Differentiation and compaction in the Skaergaard intrusion. Journal of Petrology 50, 813–40.CrossRefGoogle Scholar
Wager, L. R. 1960. The major element variation of the layered series of the Skaergaard intrusion and a re-estimation of the average composition of the hidden series and of successive residual magmas. Journal of Petrology 1, 364–98.CrossRefGoogle Scholar
Wager, L. R. 1963. The mechanism of adcumulus growth in the layered series of the Skaergaard intrusion. In Symposium on Layered Intrusions, vol. 1 (eds Fisher, D. J., Freuh, A. J., Hulbert, C. S. & Tiley, C. E.), pp. 19. Mineralogical Society of America Special Papers.Google Scholar
Wager, L. R., Brown, G. M. & Wadsworth, W. J. 1960. Types of igneous cumulate. Journal of Petrology 1, 7385.CrossRefGoogle Scholar
Waters, C. & Boudreau, A. E. 1996. A reevaluation of crystal-size distributions in chrome-spinel cumulates. American Mineralogist 81, 1452–9.CrossRefGoogle Scholar