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Cathodoluminescence and microporosity in alkali feldspars from the Blå Måne Sø perthosite, South Greenland

Published online by Cambridge University Press:  05 July 2018

Adrian A. Finch
Affiliation:
Department of Geology and Geophysics, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, U.K.
F. David L. Walker
Affiliation:
Department of Geology and Geophysics, University of Edinburgh, West Mains Road, Edinburgh EH9 3JW, U.K.

Abstract

Samples from a traverse across the Blå Måne Sø perthosite unit in the Tugtutôq Central Complex of the Gardar province, South Greenland have been examined for cathodoluminescence characteristics, microporosity and δ18O isotopic values. Reddening of cathodoluminescence colours in alkali feldspars (normally blue) from the unit may be correlated with increased microporosity of the feldspars as determined using scanning electron microscopy. δ18O values of all samples lie within the range of values expected of juvenile fluids, independent of the level of alteration indicated by cathodoluminescence studies.

Observations are consistent with previous suggestions that levels of alkali feldspar microporosity and levels of fluid alteration (as determined by cathodoluminescence of alkali feldspars) are related phenomena. Oxygen isotope ratios suggest that the fluid is largely juvenile in origin, with, perhaps, some meteoric (low δ18O) component.

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1991

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Footnotes

*

Present address: Department of Chemistry, University of Aberdeen, Meston Walk, Old Aberdeen AB9 2UE, U.K.

References

Andersen, T. (1989) Mineral. Mag., 53, 395414.CrossRefGoogle Scholar
Brace, W. F., Silver, E., Hadley, K., and Goetze, C. (1972) Science, 178, 162–4.CrossRefGoogle Scholar
Conover, W. J. (1980) Practical Non-parametric Statistics. 2nd ed., John Wiley and Sons.Google Scholar
De St. Jorre, L. and Smith, D. G. W. (1988) Can. Mineral., 26, 301–8.Google Scholar
Emeleus, C. H. and Upton, B. G. J. (1976) In The Geology of Greenland (Escher, A. and Watt, W. S., eds.), Grønlands Geologiske Undersøgelse, Copenhagen, 152-81.Google Scholar
Finch, A. A. (1990) The Chemical and Isotopic Nature of Fluids Associated with Alkaline Magmatism, South Greenland. Unpubl. Ph.D. thesis. University of Edinburgh.Google Scholar
Geake, J. E., Walker, G., Telfer, D. J., and Mills, A. A. (1977) Phil. Trans. Roy. Soc. London, A285, 403-8.Google Scholar
Konnerup-Madsen, J., Kreulen, R., and Rose-Hansen, J. (1988) Bull. Mineral., III, 567-76.Google Scholar
Mariano, A. N. (1976) In Simposio Internacional de Carbonatitos, 1. Pocos de Caldas. Google Scholar
Mariano, A. N. (1979) Geol. Assoc. Can.-Min. Assoc. Can., Jt. Ann. Meet, Program Abs. 4, 65.Google Scholar
Mariano, A. N. (1988) In Cathodoluminescence of Geologic Materials (Marshall, D. J., ed.), Unwin Hyman.Google Scholar
Montgomery, C. W. and Brace, W. F. (1975) Contrib. Mineral. Petrol., 52, 1728.CrossRefGoogle Scholar
Parsons, I. (1978) Mineral. Mag., 42, 117.CrossRefGoogle Scholar
Parsons, I. (1979) J. Petrol., 20, 653–94.CrossRefGoogle Scholar
Parsons, I. (1980) Trans. Roy. Soc. Edinb., Earth Sci., 71, 112.CrossRefGoogle Scholar
Parsons, I. and Brown, W. L. (1984) In Feldspars and Feldspathoids (Brown, W. L., ed.), NATO ASI series C, 317-71.Google Scholar
Rae, D. and Chambers, A. D. (1988) Trans. Roy. Soc. Edinb., Earth Sci., 79, 112.CrossRefGoogle Scholar
Sheppard, S. M. F. (1986) Min. Soc. America Spec. Publ, 16, 319–71.Google Scholar
Sigel, G. H. jr. (1973) J. Non-crystalline Solids, 13, 372–98.CrossRefGoogle Scholar
Smith, J. V. and Stenstrom, R. C. (1965) J. Geol, 73, 627–35.CrossRefGoogle Scholar
Sprunt, E. S. and Brace, W. F. (1974) Int. J. Rock Mech. Min. Sci. and Geomech. Abs., 11, 139–50.CrossRefGoogle Scholar
Stephenson, D. (1976) Bull. Gr0nlands Geol. Unders., 118, 55 pp.Google Scholar
Taylor, H. P. Jr. and Forester, R. W. (1979) J. Petrol., 20, 355419.CrossRefGoogle Scholar
Upton, B. G. J. (1964) Meddr. Grønland, 169, no. 32,. 62 pp.Google Scholar
Upton, B. G. J. and Emeleus, C. H. (1987) In Alkaline Igneous Rocks (Fitton, J. G. and Upton, B. G. J., eds), Geol. Soc. London Spec. Publ. no. 20, 447-71.Google Scholar
Upton, B. G. J. Martin, A. R. and Stephenson, D. (1991) J. Vol- canology Geotherm. Res. Google Scholar
Walker, F. D. L. (1990) Contrib. Mineral. Petrol, 106, 124–9.Google Scholar
Worden, R., Walker, F. D. L., Parsons, I., and Brown, W. L. (1989) Terra Abs., 1, 290–1.Google Scholar
Worden, R., Walker, F. D. L., Parsons, I., and Brown, W. L. (1990) Contrib. Mineral. Petrol., 104, 507–14.CrossRefGoogle Scholar