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Disequilibrium textures in the Leinster Granite Complex, SE Ireland: evidence for acid-acid magma mixing

Published online by Cambridge University Press:  05 July 2018

S. E. Grogan  and
R. J. Reavy
S. E. Grogan
Affiliation:
Department of Geology, National University of Ireland, Cork, Ireland
R. J. Reavy
Affiliation:
Department of Geology, National University of Ireland, Cork, Ireland
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Abstract

The LGC (Leinster Granite Complex) in SE Ireland consists of five plutons or Units. Units 1 and 3 display complex magmatic disequilibrium textures described here for the first time. The textures indicative of disequilibrium include boxy cellular plagioclase, oscillatory zoning, calcic spike zones and combinations of these within individual plagioclase feldspar crystals. The textures are interpreted as having formed in a dynamic magmatic environment which facilitated acid-acid mixing on a variety of scales and at a variety of stages between source to emplacement. It is proposed that the restricted distribution of disequilibrium textures was a result of the complex strain regime operating within the crust during assembly of Units 1 and 3.

Keywords

graniteLeinsterSE Irelandmagma mixingdisequilibriummicrotextures
Type
Research Article
Information
Mineralogical Magazine , Volume 66 , Issue 6 , December 2002 , pp. 929 - 939
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2002

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References

Anderson, A.T. Jr., (1984) Probable relations between plagioclase zoning and magma dynamics, Fuego Volcano, Guatemala. American Mineralogist, 69, 660–676.Google Scholar
Anderson, A.T. Jr., and Eklund, O. (1994) Cellular plagioclase intergrowths as a result of crystal magma mixing in the Proterozoic and Aland rapakivi batholith, S.W. Finland. Contributions to Mineralogy and Petrology, 117, 124–136.CrossRefGoogle Scholar
Arzi, A.A. (1978) Critical phenomena in the rheology of partially melted rocks. Tectonophysics, 44, 173–184.CrossRefGoogle Scholar
Barbarin, B. (1990) Plagioclase xenocrysts and mafic magmatic enclaves in some granitoids of the Sierra Nevada Batholith, California. Journal of Geophysical Research, 95, 17747–17756.CrossRefGoogle Scholar
Brück, P.M. and O'Connor, P.J. (1977) The Leinster Batholith: Geology and geochemistry of the northern Units. Geological Survey of Ireland Bulletin, 2, 107–141.Google Scholar
D'Lemos, R.S. (1996) Mixing between granitic and dioritic crystal mushes, Guernsey, Channel Islands, UK. Lithos, 38, 233–257.CrossRefGoogle Scholar
Hibbard, M.J. (1981) The magma mixing origin of mantled feldspars. Contributions to Mineralogy and Petrology, 76, 158–170.CrossRefGoogle Scholar
Hibbard, M.J. (1991) Textural anatomy of twelve magma mixed granitoid systems. Pp. 431–444 in: Enclaves and Granite Petrology (Didier, J. and Barbarin, B., editors). Elsevier Science Publishers, Amsterdam.Google Scholar
Loomis, T.P. (1982) Numerical simulations of crystallisation processes of plagioclase in complex melts: the origin of major and oscillatory zoning in plagioclase. Contributions to Mineralogy and Petrology, 81, 219–229.CrossRefGoogle Scholar
Mohr, P. (1991) Cryptic Sr and Nd isotopic variation across the Leinster Granite Complex, SE Ireland. Geological Magazine, 128, 251–256.CrossRefGoogle Scholar
O'Connor, P.J., Aftalion, M. and Kennan, P.S. (1989) Isotopic U-Pb ages of zircon and monazite from the Leinster Granite, SE Ireland. Geological Magazine, 126, 725–728.CrossRefGoogle Scholar
O'Mahony, M.J. (2001) The structural and metamorphic features of the central and southern units of the Leinster Granite Complex, S.E. Ireland. Unpubl. PhD thesis, NUI, Cork, Ireland.Google Scholar
Pembroke, J. and D'Lemos, R.S. (1996) Mixing between granite magmas: Evidence from the Southwest Granite Complex of Jersey. Proceedings of the Ussher Society, 9, 105–113.Google Scholar
Sweetman, T.M. (1987) The geochemistry of the Blackstairs Unit of the Leinster Granite, Ireland. Journal of the Geological Society, London, 144, 971–984.CrossRefGoogle Scholar
Vance, J.A. (1962) Zoning in igneous plagioclase: normal and oscillatory zoning. American Journal of Science, 260, 746–760.CrossRefGoogle Scholar
Vance, J.A. (1969) On synneusis. Contributions to Mineralogy and Petrology, 24, 7–29.CrossRefGoogle Scholar
Wiebe, R.A. (1968) Plagioclase stratigraphy: a record of magmatic conditions and events in a granite stock. American Journal of Science, 266, 690–703.CrossRefGoogle Scholar
Wyllie, P.J., Cox, K.G. and Biggar, G.M. (1962) The habit of apatite in synthetic systems and igneous rocks. Journal of Petrology, 3, 238–243.CrossRefGoogle Scholar