Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-25T23:57:24.511Z Has data issue: false hasContentIssue false

Adinoles revisited: hydrothermal Na(Ca)-metasomatism of pelite screens adjacent to tholeiitic dykes in the Dublin terrane, Ireland

Published online by Cambridge University Press:  05 July 2018

Norman S. Angus
Affiliation:
Department of Earth Sciences, University of Sheffield, Dainton Building, Brookhill, Sheffield S3 7HF, UK
Raymond Kanaris-Sotiriou
Affiliation:
Department of Earth Sciences, University of Sheffield, Dainton Building, Brookhill, Sheffield S3 7HF, UK

Abstract

The albitisation of pelitic metasediments to form adinoles adjacent to minor mafic intrusions has in the past been attributed to Na-bearing metasomatizing fluids emanating from the intrusions themselves. The chemistry and mineralogy of adinoles associated with dykes forming a high-intensity swarm in the Tallaght area, County Dublin, Ireland, confirms a metasomatic origin for the adinoles described, with Na and to a lesser extent Ca introduced into the country rocks at the expense of K. We suggest, however, that the source of the metasomatizing fluids was external to the dykes — possibly involving a hydrothermal system driven by an underlying magma reservoir that was parental to the dykes and also contributed volatiles to the hydrothermal system by degassing. Heat flow from the dykes was instrumental in promoting the reaction between muscovite in the country rock pelites and the Na(Ca)-bearing fluids to form albite, temperatures of ∼350°C in the country rocks within a metre of the contact being indicated. The mechanism of adinolization proposed is shown to be compatible with recent experimental work on the hydrothermal alteration of greywackes and basalts and also with the likely temperature gradients adjacent to dykes.

Type
Geochemistry
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1995

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

Agrell, S.O. (1939) The adinoles of Dinas Head, Cornwall. Mineral. Mag., 25, 305–37.Google Scholar
Angus, N.S and Brindley, J.C. (1970) A swarm of Caledonian dolerite intrusions in the Tallaght Hills, Co. Dublin. Proc. Royal Irish Acad.,, 69B, 165–178.Google Scholar
Angus, N.S. (in press) Geochemistry and petrogenesis of tholeiitic dykes in the Dublin Terrane of the Leinster Massif, Ireland. Geol. Mag. Google Scholar
Arkhipova, A.I and Natorkhin, I.A. (1969) Mass transfer between differentiated trap intrusions and their host rocks. Doklady Academy of Sciences, USSR, Earth Sci. Sect, 186, 239–242.Google Scholar
Barton, M.D., Ilchik, R.P. and Marikos, M.A. (1991) Metasomatism. In Contact Metamorphism (Kerrick, D.M., ed.) Reviews in Mineralogy, 26, Mineralogical Society of America.Google Scholar
Bischoff, J.L., Radtke, A.S. and Rosenbauer, R.J. (1981) Hydrothermal alteration of graywacke by brine and seawater: roles of alteration and chloride complexing on metal solubilization at 200°C and 350°C. Econ. Geol, 76, 659–676.CrossRefGoogle Scholar
Bruck, P.M., Potter, T.L. and Downie, C. (1974) The Lower Palaeozoic stratigraphy of the northern part of the Leinster Massif. Proc. Royal Irish Acad., 74B, 75–84.Google Scholar
Buchan, K.L. and Schwarz, E.I. (1987) Determination of the maximum temperature profile across dyke contacts using remanent magnetization and its applications. In Mafic dyke swarms. (Halls, H.C. and Fahrig, W.F., eds.) Geological Association of Canada Special Paper 34, pp 221-7.Google Scholar
Butler, B.C.M. (1961) Metamorphism and metasomatism of rocks of the Moine Series by a dolerite plug in Glenmore, Ardnamurchan. Mineral. Mag., 32, 866–97.Google Scholar
Davies, R.G. (1956) The Pen-y-gader dolerite and its metasomatic effects on the Lyn-y-gader sediments. Geol. Mag., 93, 153–72.CrossRefGoogle Scholar
Delaney, P.T. (1987) Heat transfer during emplacement and cooling of mafic dykes. In Mafic dyke swarms. (Halls, H.C. and Fahrig, W.F., eds.) Geological Association of Canada Special Paper 34, pp 31–46.Google Scholar
Dewey, H (1915) On spilosites and adinoles from north Cornwall. Trans. Royal Geol. Soc. Cornwall, 15, 71–84.Google Scholar
Djordevic, P. and Karamata, S. (1972) Observations on the desmositic and spilositic rocks in the Dinarides. Contrib. Mineral. Petrol., 34, 326–35.CrossRefGoogle Scholar
Dypvik, H. (1979) Major and minor trace element chemistry of Triassic black shales near a dolerite intrusion at Sassenfjorden, Spitsbergen. Chem. Geol, 25, 53–65.CrossRefGoogle Scholar
Floyd, P.A., Exley, C.S. and Styles, M.T. (1993) Igneous rocks of South-West England. Geological conservation review series, 5 (Wimbledon, W.A. and Banham, P.H., eds.) Joint Nature Conservation Committee. Chapman and Hall, London.CrossRefGoogle Scholar
Fritz, P. and Frape, S.K. (1987) (Eds.) Saline water and gases in crystalline rocks. Geol. Assoc. Canada Special Paper 33.Google Scholar
Fyffe, L.R. and Pickerill, R.K. (1993) Geochemistry of Upper Cambrian-Lower Ordovician black shale along a northeastern Appalachian transect. Bull. Geol. Soc. Amer., 105, 897–910.2.3.CO;2>CrossRefGoogle Scholar
Giggenbach, W.F. (1984) Mass transfer in hydrothermal alteration-a conceptual approach. Geochim. Cosmochim. Ada, 48, 2693–711.CrossRefGoogle Scholar
Giggenbach, W.F. (1988) Geothermal solute equilibria. Derivation of Na—K—Mg—Ca geoindicators. Geochim. Cosmochim. Ada, 52, 2749–65.CrossRefGoogle Scholar
Grant, J.A. (1986) The isocon diagram-a simple solution to Gresen's equation for metasomatic alteration. Econ. Geol., 81, 1976–82.CrossRefGoogle Scholar
Hausmann, J.F.L. (1828) Handbuch der Mineralogie, 1, 654, Bandenhoeck, Ruprecht, Gottingen-from Tomkieff (1983) (Walton, E.K. et al., eds.) Dictionary of Petrology, Wiley-Interscience, Chi-chester]Google Scholar
Hemley, JJ. and Jones, W.R. (1964) Chemical aspects of hydrothermal alteration with emphasis on hydrogen metasomatism. Econ. Geol, 59, 538–69.CrossRefGoogle Scholar
Holland, H.D. (1967) Gangue minerals in hydrothermal deposits. In Geochemistry of hydrothermal ore deposits (Barnes, H.L., ed.), Holt, Rinehart and Winston, New York.Google Scholar
Kish, L. and Cuney, M. (1981) Uraninite-albite veins from the Mistamisk Valley of the Labrador Trough, Quebec. Mineral. Mag., 44, 471–83.CrossRefGoogle Scholar
Max, M.D., Barker, A.J. & Martinez, J. (1990) Terrane assemblage of the Leinster Massif, SE Ireland, during the Lower Palaeozoic. J. Geol. Soc, London, 147, 1035–50.CrossRefGoogle Scholar
Norrish, K. and Hutton, J.T. (1969) An accurate X-ray spectrographic method for the analysis of a wide range of geological samples. Geochim. Cosmochim. Ada, 33, 431–53.CrossRefGoogle Scholar
O'Conner, P.J., Aftalion, M. & Kennan, P.S. (1989) Isotopic ages of zircon and monazite from the Leinster Granite, Southeast Ireland. Geol. Mag., 126, 725–8.CrossRefGoogle Scholar
Parmentier, E.M. (1979) Two-phase natural convection adjacent to a vertical heated surface in a permeable medium. Internat. J. Heat Mass Transfer, 22, 849–55.CrossRefGoogle Scholar
Parmentier, E.M. and Schedl, A. (1981) Thermal aureoles of igneous intrusions: some possible indications of hydrothermal convective cooling. J. Geol., 89, 1–22.CrossRefGoogle Scholar
Pitcher, W.S. and Berger, A.R. (1972) The geology of Donegal: A study of granite emplacement and unroofing. Interscience (Wiley), New York.Google Scholar
Riley, J.P. (1958a) The rapid analysis of silicate rocks and minerals. Analytica Chimica Acta, 19, 413–28.CrossRefGoogle Scholar
Riley, J.P. (1958ft ) Simultaneous determination of water and carbon dioxide in rocks and minerals. Analyst, 83, 42–9.CrossRefGoogle Scholar
Rosenbauer, R.J., Bischoff, J.L. and Radtke, A.S. (1983) Hydrothermal alteration of graywacke and basalt by 4 molal NaCl. Econ. Geol., 78, 1701–10.CrossRefGoogle Scholar
Rosenbauer, R.J, Bischoff, J.L. and Zierenberg, R.A. (1988) The laboratory albitization of mid-ocean ridge basalt. J. Geol, 96, 237–44.CrossRefGoogle Scholar
Ruhlmann, F., Raynal, M. and Lavoie, S. (1986) Un example de metasomatisme alcalin albite-uranium dans le bassin des Monts Otish, Quebec. Canad. J. Earth Sci., 23, 1742–52.CrossRefGoogle Scholar
Turekian, K.T and Wedepohl, K.H. (1961) Distribution of the elements in some major units of the Earth's crust. Bull. Geol. Soc. Amer., 72, 175–92.CrossRefGoogle Scholar
Williams, C.T., Symes, R.F. and Din, V.K. (1993) Mobility and fixation of a variety of elements, in particular boron, during the metasomatic develop-ment of adinoles at Dinas Head, Cornwall. Bull.Nat.Hist.Mus.Lond. (Geol), 49 (2), 81-98.Google Scholar
[Zincken, J.C.L. (1841) Karsten's und von Dechen's Archiv, 15, p.395, Breslau, Berlin-from Tomkieff (1983) (Walton, E.K. et al, eds.) Dictionary of Petrology, Wiley-Interscience, Chichester]Google Scholar