Hostname: page-component-cd9895bd7-lnqnp Total loading time: 0 Render date: 2024-12-18T11:06:06.020Z Has data issue: false hasContentIssue false

Evolution of fluid phases associated with lithium pegmatites from SE Ireland

Published online by Cambridge University Press:  05 July 2018

Martin P. Whitworth
Affiliation:
Dept of Geology, Imperial College, London, SW72BP
Andrew H. Rankin
Affiliation:
Dept of Geology, Imperial College, London, SW72BP

Abstract

Fluid inclusions in quartz from internally zoned barren and spodumene-bearing pegmatites associated with the Leinster granite of SE Ireland represent a variety of early and late hydrothermal fluids responsible for the development of pegmatites. Microthermometry and optical examination reveal two main populations of inclusions. The first (Type 1) comprises low-moderate salinity brines which homogenized at temperatures up to about 400 °C. The second (Type 2) appear to postdate the first population and are characteristically more saline and homogenized at temperatures mostly below 250 °C. Isochores for model type 1 inclusion fluids indicate that a late-magmatic/early-hydrothermal fluid developed from the Leinster granite at 675 °C. and 2.5 kbar and cooled isobarically into the spodumene stability field where complete crystallization of the pegmatites took place. Later, more saline, type 2 fluids of unknown origin may have contributed to the alteration of spodumene to muscovite and albite with the accompanying release of lithium from the lattice of spodumene.

Type
Petrology and Geochemistry
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1989

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Alderton, D. H. M. and Rankin, A. H. (1982) The character and evolution of hydrothermal fluids associated with the kaolinised St. Austell granite. J. Geol. Soc. Lond. 140, 297-309.CrossRefGoogle Scholar
Boyarskaya, R. V., Dolomanova, Y. I., Nosik, L. P., and Fadyukov , Y. M. (1977) Morphology and chemical compositions of inclusions of parent solutions in reticulate quartz from pegmatites of Volhyn; data of scannirg electron microscopy and mass spectrometry. Abst. Fluid inclusion abstracts. Proc. COFFI 10, 34.Google Scholar
Brindley, J. C. (1957) Basement rocks. In A View of Ireland (Meanan, J. and Webb, D. A., eds.), Dublin, 1522.Google Scholar
Brindley, J. C. (1973) The Structural setting of the Leinster granite, Ireland. Sci. proc. R. Dublin Soc., Ser. A5, 2736.Google Scholar
Brück, P. M. (1974) Granite varieties and structures of the Northern and Upper Liffey Valley Units of the Leinster batholith. Bull. Geol. Surv. Ireland, 1, 381-94.Google Scholar
Brück, P. M. and O'Connor, P. J. (1977) The Leinster batholith: geology and geochemistry of the northern units. Ibid. 2, 107-42.Google Scholar
Brück, P. M., Colthurst, J. R. J., Feely, M., Gardiner, P. R. R., Penney, S. R., Reeves, T. J., Shannon, P. M., Smith, D. G., and Vanguestaine, M. (1979) Southeast Ireland: Lower Palaeozoic stratigraphy and depositional history. In The Caledonides of the British lsles—Reviewed (Harris, A. L., Holland, C. H. and Leake, B. E., eds.) Scottish Academic Press, 533-44.Google Scholar
Burnham, C. W. (1979) Magmas and hydrothermai fluids. In Geochemistry of hydrothermal ore deposits (Barnes, H. L., ed.) Wiley and Son, New York, 71136.Google Scholar
Cameron, E. N., Jahns, R. H., McNair, A. H., and Page, L. R. (1949) Internal structure of granitic pegmatites. Econ. Geol. Monogr. 2.Google Scholar
Černý, P. (1982) Anatomy and classification of granitic pegmatites. In Short course in granitic pegmatites in science and industry (Černý, P., ed.). Min. Assoc. Can. 12, 1-40.Google Scholar
Černý, P. and Ferguson, R. B. (1982). The Tanco pegmatite at Bernic Lake, Manitoba. IV. Petalite and spodumene relations. Can. Mineral. 11, 660-78.Google Scholar
Chryssoulis, S. L. and Rankin, A. H. (1988) Decrepito metry of fluid inclusions in quartz from the Guadalcazar granite of Mexico. Mineral. Dep. 23, 42-9.CrossRefGoogle Scholar
Cooper, M. A. and Brück, P. M. (1983) Tectonic relationships of the Leinster granite, Ireland. Geol. J. 18, 351-60CrossRefGoogle Scholar
Crawford, M. L. (1981) Fluid inclusions in metamorphic rocks—low and medium grade. Short course in fluid inclusions: applications to petrology (Hollister, L. S. and Crawford, M. L., eds.)., Min. Assoc. Can. 6, 157- 81.Google Scholar
Elsdon, R. and Kennan, P. S, (1982) Age of sulphide deposits on the margin of the Leinster granite, Ireland. I. Metallization associated with acid magmatism 6 (Evans, A. M., ed.) Wiley, Chichester, 85-9.Google Scholar
Gallagher, V. (1987) Tourmaline-bearing rocks and granite related metallogenesis in SE Ireland. Unpubl. Ph.D. thesis, Nat. Univ. Ireland.Google Scholar
Hall, D. L., Sterner, S. M., and Bodnar, R. J. (1988) Freezing point depression of NaCl-KCl-H2O solutions. Econ. Geol. 83, 197-202.CrossRefGoogle Scholar
Halls, C. (1987) A Mechanistic approach to the paragenetic interpretation of mineral lodes in Cornwall. Proc. Ussher Soc. 6, 548-54.Google Scholar
Kennan, P. S., McArdle, P., Williams, F. M., and Doyle, E. (1986) A Review of metal deposits associated with the Leinster granite, SE Ireland and a model for their genesis. In Geology and genesis of mineral deposits in Ireland (Andrews, C. J. et al., eds.), Irish Assoc. Econ. Geol., Dublin, 201-10.Google Scholar
Kesler, T. L. (1978) Raw lithium supplies. Mining Engin. 30, 283.Google Scholar
Konnerup-Madsen, J. (1977) Composition and microthermometry of fluid inclusions in the Kleivan granite, south Norway. Am. J. Sci. 277, 673-96.CrossRefGoogle Scholar
Konnerup-Madsen, J. (1979) Fluid inclusions in quartz from deep-seated granitic intrusions, south Norway. Lithos, 12, 13-23.Google Scholar
Kunasz, I. (1982) Foote mineral company—Kings Mountain Operation. In Short course in granitic pegmatites in science and industry (Černý, P., ed.), Min. Assoc. Can. 12, 505-12.Google Scholar
London, D. (1984) Experimental phase equilibria in the system LiAlSiO4-SiO2-H2O: a petrogenetic grid for lithium-rich pegmatites. Am. Mineral. 69, 995-1004.Google Scholar
London, D. (1985) Origin and significance of inclusions in quartz: a cautionary example from the Tanco pegmatite, Manitoba. Econ. Geol. 80, 1988-95.CrossRefGoogle Scholar
London, D. (1986) Magmatic-hydrothermal transition in the Tanco rare-element pegmatite: evidence from fluid inclusions and phase-equilibrium experiments. Am. Mineral. 71, 376-95.Google Scholar
London, D. and Butt, D. M. (1982) Alteration of spodumene, montebrasite and lithiophilite in pegmatites of the White Picacho district, Arizona. Ibid. 67, 97-113.Google Scholar
Luecke, W. (1981) Lithium pegmatites in the Leinster granite (Southeast Ireland ). Chem. Geol. 34, 195-233.CrossRefGoogle Scholar
McArdle, P. (1981) The Country rocks flanking the Leinster granit e between Aughrim and Ballymurphy. Bull. Geol. Surv. Ireland, 3, 85-95.Google Scholar
McArdle, P. and Kennedy, M. J (1985) The East Carlow deformation zone and its regional implications. Ibid. 3, 237-55.Google Scholar
Naumov, G. B., Kovalenko, V. I., Ivanov, G. F., and Vladykín, N. B. (1977) Genesis of topaz according to the data on microinclusions. Geochem. lnternat. 14, 1-8.Google Scholar
O'Connor, P. J. and Brück, P. M. (1978) Age and origin of the Leinster granite. J. Earth Sci. R. Dubl. Soc. 1, 105-13.Google Scholar
Olsen, K. I. and Griffin, W. L. (1984a) Fluid inclusion studies of the Drammen granite, Oslo paleorift, Norway. I. Microthermometry. Contrib. Mineral. Petrol. 87, 1-14.CrossRefGoogle Scholar
Olsen, K. I. and Griffin, W. L. (1984b) Fluid inclusion studies of the Drammen granite, Oslo paleorift, Norway. II. Gas-and leachate analyses of miarolitic quartz. Ibid. 87, 15-23.CrossRefGoogle Scholar
Pêcher, A., Lespinasse, M., and Leroy, J. (1985) Relation between fluid inclusion trails and regional stress field: a tool for fluid chronology. The example of an intragranitic uranium ore deposit, Northwest Massif Central, France. Lithos, 18, 229-37.CrossRefGoogle Scholar
Piwinskii, A. J. and Wyllie, P. J. (1970) Experimental studies on igneous rock series: felsic body suite from the Needle Point pluton, Wallowa batholith, Oregon. Y. Geol. 78, 52-76.Google Scholar
Potter, R. W. and Brown, D. L. (1977) The volumetric properties of aqueous sodium chloride solutions from 0 to 500 ∼ 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
Potter, R. W. and Brown, D. L., Clynne, M. A., and Brown, D. L. (1978) Freezing point depression of aqueous sodium chloride solutions. Econ. Geol. 73, 284-5.CrossRefGoogle Scholar
Rankin, A. H. and Alderton, D. H. M. (1983) Fluid inclusion petrography of SW England granites and its potential in mineral exploration. Mineral. Dep. 18, 335-47.CrossRefGoogle Scholar
Rankin, A. H. and Alderton, D. H. M. (1985) Fluids in granites from southwest England. In High heat producing (HHP) granites, hydrothermal circulation and ore genesis. Inst. Min. Metall., 287300.Google Scholar
Rankin, A. H. and Alderton, D. H. M. and Criddle, A. J. (1985) Mineralizing fluids and metastable low-temperature inclusion brines at Llanharry iron deposit, South Wales. Trans. Inst. Min. Metall. 94, B12632.Google Scholar
Rankin, A. H. and Alderton, D. H. M. and Graham, M. J. (1988) Na, K and Li contents of mineralizing fluids in the North Pennines orefield and their genetic significance. Ibid. 97, B99-107.Google Scholar
Roedder, E. (1971) Metastability in fluid inclusions. Proc. IMA-IA GOD meetings 1970, 327-34. Spec. Iss. Soc. Min. Geol. Japan.Google Scholar
Roedder, E. (1984) Fluid Inclusions. Reviews in mineralogy 12, Min. Soc. Am., 644pp.Google Scholar
Roedder, E. and Bodnar, R. J. (1980) Geologic pressure determinations from fluid inclusion studies. Ann. Rev. Earth Planet. Sci. 8, 263-301.CrossRefGoogle Scholar
Rosenbauer, R. J. and Bischoff, J. L. (1987) Pressure-composition relations for coexisting gases and liquids and the critical points in the system NaCl-H2O at 450, 475 and 500 °. Geochim. Cosmochim. Acta, 51, 2349-54.CrossRefGoogle Scholar
Rossovskii, L. N. (1981) Rare-element pegmatites with precious stones and conditions of their formation (Hindu Kush). Int. Geol. Rev. 23, 1312-20.CrossRefGoogle Scholar
Scoon, R. N. (1978) Lithium pegmatites in the Leinster granites of south-east Ireland. Unpub. M.Sc. thesis, Univ. Coll. Cardiff.Google Scholar
Shepherd, T. J., Miller, M. F., Scrivener, R. C., and Darbyshire, D. P. F. (1985a) Hydrothermal fluid evolution in relation to mineralization in southwest England with special reference to the Dartmoor/Bodmin area. In High heat producing (HHP) granites, hydrothermal circulation and ore genesis. Inst. Min. Metall., 345-64.Google Scholar
Shepherd, T. J., Miller, M. F., Scrivener, R. C., and Darbyshire, D. P. F., Rankin, A. H., and Alderton, D. H. M. (1985b) A practical guide to fluid inclusion studies. Blackie, London, 239pp.Google Scholar
Steiger, R. (1977) Prospecting for lithium and tungsten in Ireland. In Prospecting in areas of glaciated terrain, Helsinki. Inst. Min. Metall., 1424.Google Scholar
Steiger, R. and von Knorring, O. (1974) A lithium pegmatite belt in Ireland. J. Earth Sci. Leeds Geol. Assoc. 8, 433-43.Google Scholar
Sweetman, T. (1988) The geochemistry of the Blackstairs Unit of the Leinster granite, Ireland. J. Geol. Soc. 144, 971-84.CrossRefGoogle Scholar
Thomson, T. (1836) Outlines of mineralogy, geology and mineral analysis, Vols I-II, London.Google Scholar
Touret, J. (1981) Fluid inclusions in high grade metamorphic rocks. Short course in fluid inclusions: applications to petrology (Hollister, L. S. and Crawford, M. L., eds.). Min. Assoc. Can. 6, 182208.Google Scholar
Tuttle, O. F. (1949) Structural petrology of planes of liquid inclusions. J. Geol. 57, 331-56.CrossRefGoogle Scholar
Weisbrod, A. and Poty, B. (1975) Thermodynamics and geochemistry of the hydrothermal evolution of the Mayres pegmatite. Pétrologie, 1, 1-16 and 89-102.Google Scholar
Williams, F. M. and Kennan, P. S. (1983) Stable isotope studies of sulphide mineralization on the Leinster granite margin and some observations on its relationship to coticule and tourmalinite rocks in the aureole. Mineral. Dep. 18, 399-410.CrossRefGoogle Scholar
Zakharchenko, A. I. (1971). Time and physicochemical conditions of mobilisation, transport and precipitation of tungsten and tin in post magmatic processes. Abstract in Fluid inclusion abstracts, Proc. COFFI 6, 191-4.Google Scholar