Abstract
Mid-Miocene shoshonitic volcanism in Lesbos is preceded and followed by minor calcalkaline activity that probably terminated in the Pliocene. Two differentiation trends are recognised in the shoshonites. The older shoshonites include voluminous acid rocks (mostly ignimbrites) and show normal shoshonite REE patterns. They were probably derived from partial melting of garnet peridotite enriched in LILE, with later fractionation controlled by anhydrous phases. Cooling units in the ignimbrites show upward increase in the K content of glass, suggesting K-feldspar fractionation in a high level magma chamber. Later shoshonites and the calc-alkali rocks have HREE enrichment and contain hydrous cognate xenoliths. Partial melting of a rising periodite diapir which had been relatively enriched in HREE within the garnet stability field and then entered the spinel stability field, would produce the observed HREE enrichment pattern. Later fractionation of these younger shoshonites and calc-alkali rocks was controlled largely by hydrous phases.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Abbott, R.N., Jr.: Peritectic relations in the system An-Ab-Or-QzH2O. Can. Mineral. 15, 245–256 (1978)
Barberi, F., Gasparini, P., Innocenti, F., Villari, L.: Volcanism of the southern Tyrrhenian Sea and its geodynamic implications. J. Geophys. Res. 78, 5221–5232 (1973)
Barberi, F., Innocenti, F., Marinelli, G., Mazzuoli, R.: Vulcanismo e tettonica a placche: esempi nell'area Mediterranean. Proc. 67 Congr. Soc. Geol. Ital. 89 p. (1974)
Best, M.G.: Migration of hydrous fluids in the upper mantle and potassium variation in calc-alkaline rocks. Geology 3, 429–432 (1975)
Borsi, S., Ferrara, G., Innocenti, F., Mazzuoli, R.: Geochronology and petrology of recent volcanics in the eastern Aegean Sea (West Anatolia and Lesbos Island). Bull. Volcanol. 36, 473–496 (1973)
Boccalletti, M., Manetti, P., Peccerillo, A.: The Balkanids as an instance of a back-arc thrust belt: possible relation with the Hellenides. Bull. Geol. Soc. Am. 85, 1077–1084 (1974)
Compton, P.: Rare earth evidence for the origin of the Nuk gneisses Buksefjorden region, southern west Greenland. Contrib. Mineral. Petrol. 66, 283–293 (1978)
Dostal, J., Zentilli, M., Caelles, J.C., Clark, A.H.: Geochemistry and origin of volcanic rocks of the Andes (26°–28° S). Contrib. Mineral. Petrol. 63, 113–128 (1977)
Ewart, A.: Mineralogy and petrogenesis of the Whakamaru ignimbrite in the Maraetai area of the Taupo volcanic zone, New Zealand. N.Z.J. Geol. Geophys. 8, 611–677 (1965)
Gill, J.B.: Geochemistry of Vita Levu, Fiji and its evolution as an island arc. Contrib. Mineral. Petrol. 27, 179–203 (1970)
Hecht, J.: Geological map of Greece, 1∶50,000, Plomari-Mytilene sheet 1972
Hecht, J.: Geological map of Greece. 1∶50,000, Ayia Paraskevi sheet 1973
Hecht, J.: Geological map of Greece, 1∶50,000, Mithimna sheet 1974a
Hecht, J.: Geological map of Greece, 1∶50,000, Polychnitos sheet 1974b
Hecht, J.: Geological map of Greece, 1∶50,000, Eressos sheet 1975
Irvine, T.N., Baragar, W.R.A: A guide to the chemical classification of the common volcanic rocks. Can. J. Earth Sci. 8, 523–548 (1971)
Jacobshagen, V., Dürr, St., Kockel, E., Kopp, K.O., Kowalczyk, G.: Structure and geodynamic evolution of the Aegean Region. In: Alps, Apennines, Hellenides (H. Closs, D. Roeder, K. Schmidt, eds.), pp. 537–564. Stuttgart: Schweizerbart 1978
Jakes, P., Gill, J.B.: Rare earth elements and the island arc tholeiitic series, Earth Planet. Sci. Lett. 9, 17–28 (1970)
Kelepertsis, A.E.: Geochemistry of high K-andesites from Polichnitos area (Lesbos Island, Greece). Prakt. Akad. Athenon 52, 497–511 (1978)
Mackenzie, D.E., Chappell, B.W.: Shoshonitic and calc-alkaline lavas from the Highlands of Papua, New Guinea. Contrib. Mineral. Petrol. 34, 50–62 (1972)
McKenzie. D.P.: Active tectonics of the Aegean region: VI Colloquium on the Geology of the Aegean region (Athens), 1303–1312 (1979)
Miyashiro, A.: Volcanic rock series in island arcs and active continental margins. Am. J. Sci. 274, 321–355 (1974)
Nicholls, I.A.: Liquids in equilibrium with peridotitic mineral assemblages at high water pressures. Contrib. Mineral. Petrol. 45, 289–316 (1974)
Paraskevopoulos, G.M.: Über den Chemismus und die provinzialen Verhältnisse der tertiären und quatären Ergußgesteine des ägäischen Raumes und der benachbarten Gebiete. Tschermaks Mineral. Petrogr. Mitt. 6, 13–72 (1956)
Pe-Piper, G.: Source of Miocene ignimbrites, Lesbos, Greece. VI Colloquium on the Geology of the Aegean Region (Athens), 939–944 (1979)
Ringwood, A.E.: The petrological evolution of island arc systems. J. Geol. Soc. London 130, 183–204 (1974)
Robert, U., Cantagrel, J.M.: The basaltic volcanism in the southeastern Aegean Sea. Geochronological data and relation with geological structures. VI Colloquium on the Geology of the AEgean Region (Athens), 961–967 (1979)
Schnetzler, C.C., Philpotts, J.A.: Partition coefficients of rare-earth elements between igneous matrix material and rock-forming mineral phenocrysts — II. Geochim. Cosmochim. Acta 34, 331–340 (1970)
Wyllie, P.J.: Ultramafic rocks and the Upper Mantle. Mineral. Soc. Am., Spec. Pap. 3, 3–32 (1970)
Zielinski, R.A., Lipman, P.W., Millard, H.T., Jr.: Minor element abundances in obsidian, perlite, and felsite of calc-alkalic rhyolites. Am. Mineral. 62, 426–437 (1977)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Pe-Piper, G. Geochemistry of Miocene shoshonites, Lesbos, Greece. Contr. Mineral. and Petrol. 72, 387–396 (1980). https://doi.org/10.1007/BF00371346
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00371346