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The (?) mid Triassic volcanic rocks of Lakonia, Greece

Published online by Cambridge University Press:  01 May 2009

G. Pe-Piper
Affiliation:
Geological Laboratory, University of Patras, Patras, Greece
A. G. Panagos
Affiliation:
Geological Laboratory, University of Patras, Patras, Greece
D. J. W. Piper
Affiliation:
Geological Laboratory, University of Patras, Patras, Greece
C. N. Kotopouli
Affiliation:
Geological Laboratory, University of Patras, Patras, Greece

Summary

Thick subaerial volcanic sequences of probable mid Triassic age rest unconformably on Permo-Carboniferous limestones in the ‘Phyllite Series’ within the Gavrovo-Tripolitsa zone of the external Hellenide nappes. The volcanic rocks are varied in character. Pyroclastic rocks (often reddened) predominate, but minor basalt or andesite and rhyolitic hypabyssal intrusions and flows are also found. The rocks have experienced low-grade metamorphism and the only relict primary minerals are pyroxene and rare plagioclase in basic rocks and potash feldspar in acid rocks. The most important metamorphic phases are albite, chlorite, potassium mica, epidote, hematite, quartz and pumpellyite. Twenty-seven whole-rock major-element analyses suggest that there has been some exchange of Na2O and K2O for CaO during metamorphism, but that other elements have been relatively stable. A genetic interpretation of the rocks is attempted using published geochemical discriminator diagrams. The basic rocks are tholeiitic in major element chemistry and pyroxene composition. Trace element (Hf, Ta, Th, Ce, Yb) distribution suggests magma generation at a destructive plate margin.

Type
Articles
Copyright
Copyright © Cambridge University Press 1982

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References

Brauer, R., Ittner, R. & Kowalczyk, G. 1980. Ergebnisse aus der ‘Phyllit-Serie’ SE Lakoniens (Peloponnes, Griechenland). Neues Jb. Geol. Palaeont. Mh. 135, 129–44.Google Scholar
Coombs, D. S. 1963. Trends and affinities of basaltic magmas and pyroxenes as illustrated on the diopside–olivine-silica diagram. Sp. Pap. Mineral. Soc. Am. 1, 227–50.Google Scholar
Fleury, J.-J. 1976. Unité paléogéographique originale sous le front de la nappe du Pinde-Olonos: l'Unité du Megdoras (Grèce continentale). C. r. Acad. Sci. Paris D 282, 25–8.Google Scholar
Hekinian, R. 1971. Petrological and geochemical study of spilites and associated rocks from St John, U. S. Virgin Islands. Bull. geol. Soc. Am. 82, 659–82.CrossRefGoogle Scholar
Hynes, A. 1974. Igneous activity at the birth of an ocean basin in eastern Greece. Can. J. Earth Sci. 11, 842–53.CrossRefGoogle Scholar
Irvine, T. N. & Baragar, W. R. A. 1971. A guide to the chemical classification of the common volcanic rocks. Can. J. Earth Sci. 8, 523–48.CrossRefGoogle Scholar
Jensen, L. S. 1976. A new cation plot for classifying subalkalic volcanic rocks. Misc. Pap. Ontario Dept. Mines 66.Google Scholar
Kauffmann, G. 1976. Perm und Trias im ostlichen Mittelgriechenland und auf einigen agaischen Inseln. Z. dt. geol. Gesell. 127, 387–98.Google Scholar
Le Bas, M. J. 1962. The role of aluminium in igenous clinopyroxenes with relation to their parentage. Am. J. Sci. 260, 267–88.CrossRefGoogle Scholar
Lekkas, S. & Papanikolaou, D. 1978. On the Phyllite Problem in Peloponnesus. Ann. géol. Pays hellén. 29, 395410.Google Scholar
Nisbet, E. G. & Pearce, J. A. 1977. Clinopyroxene composition in mafic lavas in different tectonic settings. Contr. Miner. Petrol. 63, 149–60.CrossRefGoogle Scholar
Panagos, A. G., Pe, G. G., Piper, D. J. W. & Kotopouli, C. N. 1979. Age and stratigraphic subdivision of the Phyllite Series, Krokee region, Peloponnese, Greece. Neues Jb. Geol. Paläont. Mh. 134, 265–73.Google Scholar
Paraskevopoulos, G. M. 1964. Die alpine Dislokationsmetamorphose in zentral-peloponnesisch-Kretischen metamorphen System. Neues Jb. Mineral. Abh. 101, 195209.Google Scholar
Pearce, J. A. 1981. Trace element characteristics of lavas from destructive plate boundaries. In Orogenic Andesites (ed. Thorpe, R. S.). New York: Wiley.Google Scholar
Pearce, T. H., Gorman, B. E. & Birkett, T. C. 1975. The TiO2-K2O-P2O5 diagram: a method of discriminating between oceanic and non-oceanic basalts. Earth Planet. Sci. Lett. 24, 419–26.CrossRefGoogle Scholar
Pearce, T. H., Gorman, B. E. & Birkett, T. C. 1977. The relationship between major element chemistry and tectonic environment of basic and intermediate volcanic rocks. Earth Planet. Sci. Lett. 36, 121–32.CrossRefGoogle Scholar
Richter, D. 1974. The paleogeographic and tectonic significance of the Gavrovo-Tripolis zone, Peloponnesus, Greece. Neues Jb. Geol. Paläont. Abh. 145, 96128.Google Scholar
Roddick, J. C., Cameron, W. E. & Smith, A. G. 1979. Permo-Triassic and Jurassic 40Ar-39Ar ages from Greek ophiolites and associated rocks. Nature, Lond. 279, 788–90.CrossRefGoogle Scholar
Smith, D. 1970. Mineralogy and petrology of the diabasic rocks in a differentiated olivine diabase sill complex, Sierra Ancha, Arizona. Contr. Miner. Petrol. 27, 95113.CrossRefGoogle Scholar
Smith, A. G. & Moore, E. M. 1974. Hellenides. In Mesozoic-Cenozoic Orogenic Belts: Data for Orogenic Studies: Alpine–Himalayan orogens. Spec. Publ. Geol. Soc. Lond. no 4, 159–85.Google Scholar
Wood, D. A., Joron, J. -L. & Treuil, M. 1979. A re-appraisal of the use of trace elements to classify and discriminate between magma series erupted in different tectonic settings. Earth Planet. Sci. Lett. 45, 326–36.CrossRefGoogle Scholar
Yoder, H. S. Jr. & Tilley, C. E. 1962. Origin of basaltic magmas: An experimental study of natural and synthetic rock systems. J. Petrol. 3, 342532.CrossRefGoogle Scholar
Yoder, H. S. Jr. 1967. Spilites and serpentinites. Yb. Carnegie Instn Wash. 65, 269–79.Google Scholar
Zainetti, L. & Thiebault, F. 1975. Les foraminiferes du Trias supérieur du Massif du Taygète (Peloponnèse meridional, Grèce). Archs Sci., Genève 28, 229236.Google Scholar