Hostname: page-component-848d4c4894-hfldf Total loading time: 0 Render date: 2024-05-23T19:58:27.463Z Has data issue: false hasContentIssue false

Petrogenesis of plagioclase phenocrysts of Mount Etna, Sicily, with particular reference to the 1983 eruption: contribution from cathodoluminescence petrography

Published online by Cambridge University Press:  05 July 2018

D. Stirling
Affiliation:
Centre for Volcanic Studies, University of Luton, Park Square, Luton LU1 3JU, UK
A. M. Duncan*
Affiliation:
Centre for Volcanic Studies, University of Luton, Park Square, Luton LU1 3JU, UK
J. E. Guest
Affiliation:
Planetary Image Centre, University College London, London NW7 4SD, UK
A. A. Finch
Affiliation:
Dept. of Environmental Sciences, University of Hertfordshire, Hatfield AL10 9AB, UK
*
*author for correspondence

Abstract

The cathodoluminescence (CL) characteristics of plagioclase phenocrysts in water-quenched lavas from the 1983 eruption of Etna have been investigated to examine the application of plagioclase CL to the study of magmatic processes. The phenocrysts have a green luminescent inner zone that is sharply bounded by a blue luminescent outer zone, with the boundary often coinciding with a concentric zone of glass inclusions.

Strong compositional differences between the green (An70–An75) and blue (An50–An60) luminescent areas are interpreted as the result of two phases of growth under differing conditions. The green luminescent cores are considered to be anorthite-rich cumulate crystals from a basic magma which have been disrupted by the injection of a more evolved melt, resulting in heterogeneous nucleation and crystallization of the outer blue luminescent zone. The relationship between the CL and the trace element contents of the plagioclase crystals is discussed.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1999 

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

Armienti, P., Pareschi, M.T., Innocenti, F. and Pompilio, M. (1994) Effects of magma storage and ascent on the kinetics of crystal growth. Contrib. Mineral. Petrol., 104, 594608.Google Scholar
Baxter, A.N. (1975) Petrology of the Older Series lavas, Mauritius, Indian Ocean. Bull. Geol. Soc. Amer., 86, 1449–58.Google Scholar
Chester, D.K., Duncan, A.M., Guest, J.E. and Kilburn, C.R.J. (1985) Mount Etna: The Anatomy of a Volcano. Chapman & Hall, London, 404 pp.Google Scholar
Condomines, M., Tanguy, J.C. and Michand, V. (1995) Magma dynamics at Mt Etna: Constraints from U-Th-Ra-Pb disequilibria and Sr - Isotopes in historical lavas. Earth Planet. Sci. Lett., 132, 2541.Google Scholar
Cristofolini, R. and Romano, R. (1982) Petrological features of the Etnean volcanic rocks. Mem. Soc. Geol. It., 23, 323–36.Google Scholar
Cristofolini, R. and Tranchina, A. (1980) Aspetti petrologici delle vulcaniti Etnee: caratteri dei fenocristalli isolati ed in aggregati (Petrological aspects of Etnean volcanics: characteristics of isolated phenocrysts and aggregates.) Rend. Soc. It. Mineral Petr., 36, 751–73 (In Italian).Google Scholar
De St Jorre, L. and Smith, D.G.W. (1988) Cathodoluminescent gallium enriched feldspars from the Thor Lake rare-metal deposit, Northwest Territories, Canada. Canad. Mineral., 26, 301–8.Google Scholar
Downes, M.J. (1973) Some experimental studies on the 1971 lavas from Etna. Phil. Trans. Roy. Soc. Lond., A274, 5562.Google Scholar
Duncan, A.M. and Preston, R.M.F. (1985) Plagioclase phenocrysts and the Alkalic Lavas of Mount Etna: A contribution to the understanding of magmatic processes (abstract). In IAVCEI 1985 Scientific Assembly: Potassic volcanism — Mount Etna volcano,Catania.Google Scholar
Finch, A.A. and Klein, J. (1999) The causes and petrological significance of cathodoluminescence emissions from alkali feldspars. Contrib. Mineral. Petrol.(in press).Google Scholar
Finch, A.A. and Walker, F.D.L. (1991) Cathodoluminescence and microporosity from the Blå Måne Sø perthosite, South Greenland. Mineral. Mag., 55, 583–9.Google Scholar
Frazzetta, G. and Romano, R. (1984) The 1983 Etna eruption; event chronology and morphological evolution of the lava flows. Bull. Volcanol., 47, 1079–96.Google Scholar
Geake, J.E., Walker, G., Telfer, D.J., Mills, A.A. and Garlick, G.FJ. (1973) Luminescence of lunar, terrestrial, and synthesised plagioclase, caused by Mn2+ and Fe3+. Proc. Fourth Lunar Science Conference, 3, Geochim. Cosmochim. Acta suppl., 4, 3181–9.Google Scholar
Götze, J., Krbetschek, M.R., Habermann, D. and Wolf, D. (1999) High resolution cathodoluminescence studies of feldspar minerals. In: Pagel, M., Barbin, V., Blanc, D. and Ohnenstetter, D. (Eds.) Cathodoluminescence in Geosciences. Springer Verlag (in press).Google Scholar
Guest, J.E. and Duncan, A.M. (1981) Internal plumbing of Mount Etna. Nature, 290, 584–6.Google Scholar
Guest, J.E., Kilburn, C.R.J., Pinkerton, H. and Duncan, A.M. (1987) The evolution of lava flow fields: observations of the 1981 and 1983 eruptions of Mount Etna, Sicily. Bull. Volcanol., 49, 527–40.Google Scholar
Gyopari, M. (1988) Temporal and spatial variations in the geochemistry and mineralogy of the younger historic lavas of Mount Etna, Sicily.PhD thesis, Plymouth Polytechnic [now University of Plymouth, UK].Google Scholar
Hirn, A., Nercessian, A., Sapin, M., Ferrucci, F. and Wittlinger, G. (1991) Seismic heterogeneity of Mt Etna: structure and activity. Geophys. J. Int., 105, 139–53.Google Scholar
Hughes, J.W., Guest, J.E. and Duncan, A.M. (1990) Changing styles of effusive eruptions on Mount Etna since A.D. 1600. In Magma Transport and Storage,(Ryan, M.P., ed.). J. Wiley, pp. 385406.Google Scholar
Johannes, W. (1978) Melting of plagioclase in the system Ab-An-H2O and Qz-Ab-An-H2O at pH20 = 5 k bar, an equilibrium problem. Contrib. Mineral Petrol., 66, 295303.Google Scholar
Keil, K., Fodor, R.V. and Bunch, T.E. (1972) Contribution to the mineral chemistry of hawaiian rocks. II. Feldspars and interstitial material from Haleakala and West Maul volcanoes, Maul, Hawaii. Contrib. Mineral. Petrol., 37, 253–76.Google Scholar
Krbetschek, M.R., Gotze, J., Dietrich, A. and Trautmann, T. (1997) Spectral information from minerals relevant for luminescence dating. Radiation Measurements, 27, 695748.Google Scholar
Kuo, L.C. and Kirkpatrick, R.J. (1982) Pre-eruption history of phyric basalts from DSDP Legs 45 and 46: evidence from morphology and zoning patterns in plagioclase. Contrib. Mineral. Petrol., 79, 1327.Google Scholar
Marfunin, A.S. (1979) Spectroscopy, Luminescence and Radiation Centres in Minerals. Springer. BerlinGoogle Scholar
Mariano, A.N. and Ring, P.J. (1975) Europium activated cathodoluminescence in minerals. Geochim. Cosmochim. Acta, 39, 649–60.Google Scholar
Mariano, A.N., Ito, J. and Ring, P.J. (1973) Cathodoluminescence of plagioclase feldspars. Abstracts with Programs, 5, 726. Geol. Soc. Amer. Boulder, CO.Google Scholar
Marshall, D.J. (1988) Cathodoluminescence of Geological Materials. Unwin Hyman.Google Scholar
Mora, C.I. and Ramsayer, K. (1992) Cathodoluminescence of coexisting plagioclases, Boel’s Butte anorthosite: CL activators and fluid flow paths. Amer. Mineral., 77, 1258–65.Google Scholar
Murray, J.B. and Guest, J.E. (1982) Vertical ground deformation on Mount Etna, 1975-1982. Bull. Geol. Soc. Amer., 93, 1166–75.Google Scholar
Ozawa, L. (1990) Cathodoluminescence Theory and Applications. VCH Publications (UK) Ltd.Google Scholar
Preston, R.M.F. and Duncan, A.M. (1979) Electron microprobe investigation of melt inclusions in plagioclase phenocrysts from Mount Etna. Mineral. Mag., 43, 181–3.Google Scholar
Rae, D.A. and Chambers, A.D. (1988) Metasomatism in the North Qôroq centre, South Greenland: cathodo-luminescence and mineral chemistry of alkali feldspars. Trans. R. Soc. Edinb: Earth Sciences., 79, 112.Google Scholar
Redmond, G., Cesbron, F., Chapoulie, R., Ohenestetter, D., Roques-Carmes, C. and Schoerer, M. (1992) Cathodoluminescenee applied to the microcharacterisation of mineral materials: A present status in experimentation and interpretation. Scan. Microsc., 6, 2368.Google Scholar
Rymer, H., Cassidy, J., Locke, C.A. and Murray, J.B. (1995) Magma movements in Etua volcano associated with the major 1991-1993 lava eruption: evidence from gravity and deformation. Bull. Volcanol., 57, 451–61.Google Scholar
Self, S. and Gunn, B.M. (1976) Petrology, volume and age relations of alkaline and saturated peralkaline volcanics from Terceira, Azores. Contrib. Mineral. Petrol., 54, 293313.Google Scholar
Sharp, A.D.L., Davis, P.M. and Grey, F. (1980) A low velocity zone beneath Mount Etua and magma storage. Nature, 287, 587–91.Google Scholar
Speit, B. and Lehmann, G. (1982) Radiation defects in feldspars. Phys. Chem. Min., 8, 7782.Google Scholar
Tanguy, J.C. (1978) Tholeiitic basalt magmatism of Mt. Etna and its relation with the Alkaline Series. Contrib. Mineral. Petrol., 66, 5167.Google Scholar
Tanguy, J.C. and Clocchiatti, R. (1984) The Etnean lavas, 1977 - 1983: petrology and mineralogy. Bull. Volcanol., 47, 965–76.Google Scholar
Telfer, D.J and Walker, G. (1978) Ligand field bands of Mn2+ and Fe3+ luminescence centres and their site occupancy in plagioclase feldspars. Modern Geology, 6, 199210.Google Scholar
Townsend, P.D., Karali, T., Rowlands, A.D., Smith, V.A. and Vazquez Lopez, G. (1999) Recent examples of cathodoluminescence as a probe of surface structure and composition. Mineral. Mag., 63, 211–26.(This issue).Google Scholar