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Preliminary fluid inclusion studies in a high-grade blueschist terrain, Syros, Greece

Published online by Cambridge University Press:  05 July 2018

Hazel Barr*
Affiliation:
Grant Institute of Geology, West Mains Road, Edinburgh EH9 3JW

Abstract

Preliminary fluid inclusion measurements have been made on quartz (whole rocks and segregations) and garnet from a blueschist terrain. Although further measurements are required, the fluids apparently associated with the blueschist event are aqueous with no thermometrically detectable CO2, a feature which is consistent with mineral-fluid equilibria studies. The salinity of the fluid inclusions is highly variable, from almost pure H2O to halite saturation, and a mechanism involving hydration reactions, such as proposed by Crawford et al. (1979), is suggested. Fluid inclusions associated with the greenschist overprint, which has affected the terrain, are also aqueous in nature.

Type
Magmatic/metamorphic environment
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1990

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Footnotes

*

Present address: Atmospheric Pollution Group, Environmental and Medical Sciences Division, B551, Harwell Laboratory, Oxfordshire OX11 0RA.

References

Altherr, R., Schliestedt, M., Okrusch, M., Seidel, E., Kreuzer, H., Harre, W., Lenze, H., Wendte, I. and Wagner, G. A. (1979) Geochronology of high pressure rocks on Sifnos (Cyclades, Greece. Contrib. Mineral Petrol. 70, 245-55.CrossRefGoogle Scholar
Berglund, L. and Touter, J. (1976) Garnet-biotite gneiss in ‘Systeme du Graphite’ (Madagascar): Petrology and fluid inclusion. Lithos 9, 139-48.CrossRefGoogle Scholar
Bickle, M. J. and Powell, R. (1977) Calcite-dolomite geothermometers for the iron-bearing carbonates: the Glockner area of the Tauren Window, Austria. Contrib. Mineral. Petrol. 59, 281-92.CrossRefGoogle Scholar
Crawford, M. L. (1981) Phase equilibria in aqueous fluid inclusions. I. Short Course in Fluid Inclusions: Applications to petrology, 6 (Hollister, L. S. and Crawford, M. L., eds.), Mineralogical Association of Canada, 157-81.Google Scholar
Crawford, M. L. Filter, J. and Wood, C. (1979) Saline fluid inclusions associated with retrograde metamorphism. Bull. Mineral. 102, 562-8.Google Scholar
Dixon, J. E. (1969) The metamorphic rocks of Syros, Greece. Unpubl. PhD thesis, University of Cambridge.Google Scholar
Haas, J. L. (1976) Physical properties of the coexisting phases and thermochemical properties of the H2O components in boiling NaCI solutions (Preliminary steam tables for NaCI solutions). U.S. Geol. Surv. Bull. 1421-AGoogle Scholar
Holland, T. J. B. and Powell, R. (1985) An internally consistent thermodynamic dataset with uncertainties and correlations: 2. data and results. J. Metamorphic Geol. 3, 343-70.Google Scholar
Pêcher, A. (1981) Experimental decrepitation and reequilibration of fluid inclusions in synthetic quartz. Tectonophys. 78, 567-83.CrossRefGoogle Scholar
Potter, R. W. II and Brown, D. L. (1977) The volumetric properties of aqueous sodium chloride solutions from 0-500°C at pressures up to 2000 bars based on a regression of available data in the literature. U.S. Geol. Surv. Bull. 1421-C.Google Scholar
Powell, R. (1978) Equilibrium thermodynamics in petrology: an introduction. Harper and Rowe, London.Google Scholar
Powell, R. and Evans, J. A. (1983) A new barometer for the assemblage biotite-muscovite-chlorite-quartz. J. Metamorphic Geol. 1, 331-6.CrossRefGoogle Scholar
Powell, R. and Holland, T. J. B. (1988) An internally consistent dataset with uncertainties and correlations: 3. Applications to geobarometry, worked examples and a computer program. Ibid. 6, 173-204.CrossRefGoogle Scholar
Rich, R. A. (1979) Fluid inclusion evidence of Silurian evaporites in south-east Vermont. Geol. Soc. Am. Bull. 90, 1628-43CrossRefGoogle Scholar
Ridley, J. R. (1982) Tectonic style, strain history and fabric development in a blueschist terrain, Syros, Greece. Unpubl. PhD thesis, University of Edinburgh.Google Scholar
Ridley, J. R. (1985) The significance of deformation associated with blueschist facies metamorphism on the Aegean island of Syros. In The Geological evolution of the eastern Mediterranean. Geol. Soc. Lond. Spec. Publ. 17 (Dixon, J. E. and Robertson, A. H. F., eds), 545-51.Google Scholar
Roedder, E. (1984) Fluid Inclusions. Reviews in Mineralogy, 12. Mineral. Soc. America.Google Scholar
Schliestedt, M., Altherr, R. and Matthews, A. (1987) Evolution of the Cyclades crystalline complex: petrology, isotope geochemistry and geochronology. In Chemical Transport in Metasomatic Processes (Helgason, H. C., ed.), Reidel Publishing Company, 38428.Google Scholar
Schreinemakers, F. A. H. (1915-1925) In-, mono- and divariant equilibria (English edition). Koninkl. Akad. Wetenschappen Amsterdam Prog. 1828.Google Scholar
Shepherd, T. J., Rankin, A. H. and Alderton, D. H. M. (1985) A practical guide to fluid inclusion studies. Blackie and Son Ltd. pp. 237.Google Scholar
Wijbrans, J. R., York, D. and Schliestedt, M. (1988) Laser probe 40Ar/39 age spectra of single crystals of phengite from the Cycladic blueschist belt, Greece. EOS, 69, 518.Google Scholar
Yardley, B. W. D. (1983) Ouartz veins and devolatilization during metamorphism. J. Geol. Soc. London, 140, 657-63.CrossRefGoogle Scholar
Zen, E-An (1966) Construction of pressure-temperature diagrams for multicomponent systems after the method of Schreinemakers—a geometric approach. U.S. Geol. Surv. Bull. 1125, pp. 56.Google Scholar