Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-25T04:04:07.477Z Has data issue: false hasContentIssue false

The Miocene igneous rocks in the Basal Unit of Lavrion (SE Attica, Greece): petrology and geodynamic implications

Published online by Cambridge University Press:  05 October 2007

NIKOS SKARPELIS*
Affiliation:
Department of Geology & Geoenvironment, University of Athens, Panepistimiopoli, 157 84 Zografou, Athens, Greece
BASILIOS TSIKOURAS
Affiliation:
Department of Geology, Section of Earth Materials, University of Patras, 265 00 Patras, Greece
GEORGIA PE-PIPER
Affiliation:
Department of Geology, Saint Mary's University, Halifax, NS B3H 3C3, Canada
*
*Author for correspondence: [email protected]

Abstract

The Miocene igneous rocks in the Basal Unit of the Lavrion area form part of the granitoid province of the central Aegean. Undeformed, subvertical dykes of quartz-syenite to granodiorite and granite porphyries, and a little deformed but variably altered granodiorite stock intrude metamorphic rocks of the Basal Unit. A 9.4 ± 0.3 Ma K–Ar age on feldspar for a dyke rock provides a minimum age for the igneous activity in the Basal Unit. East–west orientation of porphyry dykes is indicative of a regional extensional stress field with roughly north–south direction. Substantial extension in the Basal Unit after granodiorite emplacement is evident from widespread quartz veining associated with hydrothermal alteration of the granodiorite and the occurrence of mineralized tension gashes cutting the hydrothermally altered hornfelses. Final emplacement of the Blueschist Unit over the Basal Unit by extensional detachment post-dates contact metamorphism of the rocks surrounding the granodiorite. Geochemical diagrams show a continuous range of compositions from the dykes to the granodiorite. Radiogenic isotope compositions are compatible with a common magmatic source for the two lithologies. Elemental variations, as well as the considerable geochemical similarity of the dyke rocks to the Hercynian paragneiss of the central Cyclades, indicate that crustal melts were significant components during the evolution of the igneous rocks with fractional crystallization as an important process during later stages of evolution. The granodiorite displays geochemical signatures indicative of a significant mafic mantle-derived magma component.

Type
Original Article
Copyright
Copyright © Cambridge University Press 2007

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

Altherr, R., Henjes-Kunst, F., Matthews, A., Friedrichsen, H. & Hansen, B. T. 1988. O–Sr isotopic variations in Miocene granitoids from the Aegean: Evidence for an origin by combined assimilation and fractional crystallization. Contributions to Mineralogy and Petrology 100, 528–41.CrossRefGoogle Scholar
Altherr, R., Kreuzer, H., Lenz, H., Wendt, I., Harre, W. & Dürr, S. 1994. Further evidence for a Late Cretaceous low pressure high temperature terrane in the Cyclades, Greece. Chemie der Erde 54, 319–28.Google Scholar
Altherr, R., Kreuzer, H., Wendt, I., Lenz, H., Wagner, G. A., Keller, J., Harre, W. & Hohndorf, A. 1982. A Late Oligocene/Early Miocene high temperature belt in the Attic–Cycladic crystalline complex (SE Pelagonian, Greece). Geologisches Jahrbuch E23, 97164.Google Scholar
Altherr, R., Schliestedt, M., Okrusch, M., Seidel, E., Kreuzer, H., Harre, W., Lenz, H., Wendt, I. & Wagner, G. A. 1979. Geochronology of high-pressure rocks on Sifnos (Cyclades, Greece). Contributions to Mineralogy and Petrology 70, 245–55.CrossRefGoogle Scholar
Altherr, R. & Siebel, W. 2002. I-type plutonism in a continental back-arc setting: Miocene granitoids and monzonites from the central Aegean Sea, Greece. Contributions to Mineralogy and Petrology 143, 397415.CrossRefGoogle Scholar
Anderson, J. L. & Smith, D. R. 1995. The effects of temperature and fO2 on the Al-in-hornblende barometer. American Mineralogist 80, 549–59.Google Scholar
Avigad, D. & Garfunkel, Z. 1989. Low angle faults above and below a blueschist belt, Tinos island, Cyclades, Greece. Terra Nova 1, 182–7.CrossRefGoogle Scholar
Avigad, D., Garfunkel, Z., Jolivet, L. & Azanon, J. M. 1997. Back arc extension and denudation of Mediterranean eclogites. Tectonics 16, 924–41.CrossRefGoogle Scholar
Baltatzis, E. 1981. Contact metamorphism of a calc-silicate hornfels from Plaka area, Laurium, Greece. Neues Jahrbuch für Mineralogie Monatshefte 11, 481–8.Google Scholar
Baltatzis, E. 1996. Blueschist-to-greenschist transition and the P–T path of prasinites from the Lavrion area, Greece. Mineralogical Magazine 60, 551–61.CrossRefGoogle Scholar
Baziotis, I., Mposkos, E. & Perdikatsis, V. 2006. Reconstruction and correlation of the exhumation history of high-pressure/low-temperature metamorphic rocks from Attica. NECAM 2006 – International Conference on Neogene Magmatism of the Central Aegean and Adjacent Areas, Book of Abstracts, p. 28.Google Scholar
Böger, H. 1983. Stratigraphische und tectonische Verknuepfungen kontinentaler Sedimente des Neogens im Aegais-Raum. Geologische Rundschau 72, 771813.Google Scholar
Brichau, S., Ring, U., Ketcham, R. A., Carter, A., Stockli, D. & Brunel, M. 2006. Constraining the long-term evolution of the slip rate for a major extensional fault system in the central Aegean, Greece, using thermochronology. Earth and Planetary Science Letters 24, 293306.CrossRefGoogle Scholar
Bröcker, M., Bieling, D., Hacker, B. & Gans, P. 2004. High-Si phengites record the time of greenschist-facies overprinting: implications for models suggesting mega-detachments in the Aegean Sea. Journal of Metamorphic Geology 22, 427–42.CrossRefGoogle Scholar
Bröcker, M. & Enders, M. 1999. U–Pb zircon geochronology of unusual eclogite facies rocks from Syros and Tinos (Cyclades, Greece). Geological Magazine 136, 111–18.CrossRefGoogle Scholar
Bröcker, M. & Franz, L. 1994. The Contact Aureole on Tinos (Cyclades, Greece). Part I: Field Relationships, Petrography and P–T Conditions. Chemie der Erde 54, 262–80.Google Scholar
Bröcker, M. & Franz, L. 1998. Rb–Sr isotope studies on Tinos Island (Cyclades, Greece): Additional time constraints for metamorphism, extent of infiltration-controlled overprinting and deformational activity. Geological Magazine 135, 369–82.Google Scholar
Bröcker, M. & Keasling, A. 2006. Ionprobe U–Pb zircon ages from the high-pressure/low-temperature mélange of Syros, Greece: age diversity and the importance of pre-Eocene subduction. Journal of Metamorphic Geology 24, 615–31.CrossRefGoogle Scholar
Bröcker, M., Kreuzer, H., Matthews, A. & Okrusch, M. 1993. 39Ar/40Ar and oxygen isotope studies of polymetamorphism from Tinos island, Cycladic blueschist belt, Greece. Journal of Metamorphic Geology 11, 223–40.CrossRefGoogle Scholar
Buick, I. S. 1991. The late Alpine evolution of an extensional shear zone, Naxos, Greece. Journal of the Geological Society, London 148, 93103.CrossRefGoogle Scholar
Campresy, A. 1889. Le Laurium. Revue Univ. des Mines 6, Liége, Paris.Google Scholar
De Paolo, D. J. 1981. Trace element and isotopic effects of combined wall rock assimilation and fractional crystallization. Earth and Planetary Science Letters 53, 189202.Google Scholar
Dermitzakis, M. & Papanikolaou, D. 1980. The molasse of Paros island, Aegean Sea. Annalen des Naturhistorischen Museums in Wien 83, 5971.Google Scholar
Dubois, R. & Bignot, G. 1979. Presence d'un “hard-ground” nummulitique au sommet de la serie cretacée d'Almyropotamos (Eubée méridionale, Grèce). Conséquences. Comptes Rendu de l'Academie des Sciences de Paris 289 D, 993–5.Google Scholar
Dürr, S. & Altherr, R. 1979. Existence de klippes d'une nappe composite néogéne dans l'île de Mykonos/Cyclades (Grèce). Rapports de la Commission Internationale de la Mer Méditerranée, 25/62, 33–4.Google Scholar
Dürr, S., Altherr, R., Keller, J., Okrusch, M. & Seidel, E. 1978. The median Aegean crystalline belt: stratigraphy, structure, metamorphism, magmatism. In Alps, Apennines, Hellenides (eds Cloos, H., Roeder, D. & Schmidt, K.), pp. 455–76. Stuttgart: Schweizerbart.Google Scholar
Faure, G. 1986. Principles of isotope geology, 2nd ed. New York: John Wiley, 589 pp.Google Scholar
Faure, M., Bonneau, M. & Pons, J. 1991. Ductile deformation and syntectonic granite emplacement during the late Miocene extension of the Aegean (Greece). Bulletin Société Géologique de France 162, 311.CrossRefGoogle Scholar
Gautier, P. & Brun, J. P. 1994. Crustal-scale geometry and kinematics of late orogenic extension in the central Aegean (Cyclades and Evia island). Tectonophysics 238, 399424.CrossRefGoogle Scholar
Henderson, P. 1984. Rare Earth Element geochemistry. Amsterdam: Elsevier, 510 pp.Google Scholar
Hildreth, W. & Moorbath, S. 1988. Crustal contributions to arc magmatism in the Andes of Central Chile. Contributions to Mineralogy and Petrology 98, 455–89.Google Scholar
Holten, T., Jamtveit, B. & Meakin, P. 2000. Noise and oscillatory zoning of minerals. Geochimica et Cosmochimica Acta 64, 18931904.Google Scholar
Jolivet, L., Faccenna, C., Goffé, B., Burov, E. & Acard, F. 2003. Subduction tectonics and exhumation of high-pressure metamorphic rocks in the Mediterranean orogens. American Journal of Science 303, 353409.CrossRefGoogle Scholar
Juteau, M., Michard, A. & Albarède, F. 1986. The Pb–Sr–Nd isotope geochemistry of some recent circum Mediterranean granites. Contributions to Mineralogy and Petrology 92, 331–40.Google Scholar
Katsikatsos, G. 1977. La structure tectonique d'Attique et de l'île d'Eubée. In Proceedings of the VI Colloquium on the Geology of the Aegean Region (ed. Kallergis, G.), pp. 211–28. I.G.M.R., Athens, 1.Google Scholar
Katsikatsos, G., Migiros, G., Triantafyllis, M. & Mettos, A. 1986. Geological structure of Internal Hellenides (E. Thessaly–SW Macedonia, Euboea–Attica–Northern Cyclades Islands and Lesbos). Geological and Geophysical Research, Special Issue, I.G.M.E., Athens.Google Scholar
Katzir, Y., Matthews, A., Garfunkel, Z., Schliestedt, M. & Avigad, D. 1996. The tectono-metamorphic evolution of a dismembered ophiolite (Tinos, Cyclades, Greece). Geological Magazine 133, 237–54.Google Scholar
Kessel, G. 1990. Untersuchungen zur Deformation und Metamorphose in Attischen Krystallin, Griechenland. Berliner Geowissenschaftlicher Abhandlungen A126, 1150.Google Scholar
Koukouvelas, I. K. & Kokkalas, S. 2003. Emplacement of the Miocene west Naxos pluton (Aegean Sea, Greece): a structural study. Geological Magazine 140, 4561.CrossRefGoogle Scholar
Kumerics, C., Ring, U., Brichau, St., Glodny, J. & Monie, P. 2005. The extensional Messaria shear zone and associated brittle detachment faults, Aegean Sea, Greece. Journal of the Geological Society, London 162, 701–21.Google Scholar
Leake, B. E., Wooley, A. R., Arps, C. E. S., Birch, W. D., Gilbert, M. C., Grice, J. D., Hawthorne, F. C., Kato, A., Kisch, H. J., Krivovichev, V. G., Linthout, K., Laird, J., Mandarino, J., Maresch, W. V., Nickel, E. H., Rock, N. M. S., Schumacher, J. C., Smith, D. C., Stephenson, N. C. N., Ungaretti, L., Whittaker, E. J. W. & Youzhi, G. 1997. Nomenclature of amphiboles; report of the Subcommittee on amphiboles of the International Mineralogical Association Commission on New Minerals and Mineral Names. European Journal of Mineralogy 9, 623–51.CrossRefGoogle Scholar
Lee, J. & Lister, G. S. 1992. Late Miocene ductile extension and detachment faulting, Mykonos, Greece. Geology 20, 121–4.2.3.CO;2>CrossRefGoogle Scholar
Leleu, M. & Neumann, M. 1969. L'âge des formations d'Attique: du paleozoique au mesozoique. Comptes Rendu de l'Academie des Sciences de Paris 268, 1361–3.Google Scholar
Lister, G. S., Banga, G. & Feenstra, A. 1984. Metamorphic core complexes of the Cordilleran type in the Cyclades, Aegean Sea, Greece. Geology 12, 221–5.2.0.CO;2>CrossRefGoogle Scholar
Marinos, G. P. 1971. On the radiodating of Greek rocks (in Greek, English summary). Annales Géologiques des Pays Hélleniques 23, 175–82.Google Scholar
Marinos, G. P. & Makris, J. 1975. Geological and geophysical considerations of new mining possibilities in Laurium, Greece. Annales Géologiques des Pays Hélleniques 27, 110.Google Scholar
Marinos, G. P. & Petrascheck, W. E. 1956. Laurium. Geological & Geophysical Research 4/1, Institute for Geology and Subsurface Research, 1247.Google Scholar
Mezger, K., Altherr, R., Okrusch, M., Henjes-Kunst, F. & Kreuzer, H. 1985. Genesis of acid/basic rock associations: a case study. The Kallithea intrusive complex, Samos, Greece. Contributions to Mineralogy and Petrology 90, 353–66.CrossRefGoogle Scholar
Minoux, L., Bonneau, M. & Kienast, J. R. 1980. L'île d'Amorgos une fenêtre des zones externes, au coeur de l'Egée (Gréce), métamorphisée dans le faciés schistes bleus. Comptes Rendu de l'Academie des Sciences de Paris 291 D, 745–8.Google Scholar
Nesbitt, H. W. & Young, G. M. 1982. Early Proterozoic climates and plate motions inferred from major element chemistry of lutites. Nature 299, 715–17.Google Scholar
Okrusch, M. & Bröcker, M. 1990. Eclogite facies rocks in the Cycladic blueschist belt, Greece: A review. European Journal of Mineralogy 2, 451–78.CrossRefGoogle Scholar
Papanikolaou, D. 1987. Tectonic evolution of the Cycladic blueschist belt (Aegean sea, Greece). In Chemical Transport in Metasomatic Processes (ed. Helgeson, H. C.), pp. 429–50. Dordrecht: Reidel Publishing Company.Google Scholar
Papanikolaou, D. & Syskakis, D. 1991. Geometry of acid intrusives in Plaka, Laurium and relation between magmatism and deformation. Bulletin of the Geological Society of Greece 25 (1), 355–68.Google Scholar
Parra, T., Vidal, O. & Jolivet, L. 2002. Relation between the intensity of deformation and retrogression in blueschist metapelites of Tinos Island (Greece) evidenced by chlorite-mica local equilibria. Lithos 63, 4166.CrossRefGoogle Scholar
Pearce, J. A., Harris, N. B. W. & Tindle, A. G. 1984. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Journal of Petrology 25, 956–83.CrossRefGoogle Scholar
Pe-Piper, G. 2000. Origin of S-type granites coeval with I-type granites in the Hellenic subduction system, Miocene of Naxos, Greece. European Journal of Mineralogy 12, 859–75.CrossRefGoogle Scholar
Pe-Piper, G. & Piper, D. J. W. 2004. Miocene igneous rocks of Samos: magma evolution during continental back-arc extension. Proceedings 5th International Symposium on Eastern Mediterranean Geology, Thessaloniki, April 2004, 1212–15.Google Scholar
Pe-Piper, G., Piper, D. J. W. & Matarangas, D. 2002. Regional implications of geochemistry and style of emplacement of Miocene I-type diorite and granite, Delos, Cyclades, Greece. Lithos 60, 4766.Google Scholar
Petrakakis, K., Grasemann, B., Iglseder, C., Rambousek, C. & Zamolyi, A. 2004. Deformation and magmatism on the island of Serifos, western Cyclades. Proceedings 5th International Symposium on Eastern Mediterranean Geology, Thessaloniki, April 2004, 1228–31.Google Scholar
Reinecke, T., Altherr, R., Hartung, B., Hatzipanagiotou, K., Kreuzer, H., Harre, W., Klein, H., Keller, J., Geenen, E. & Böger, H. 1982. Remnants of a Late Cretaceous high temperature belt on the island of Anafi (Cyclades, Greece). Neues Jarhbuch für Mineralogie Abhandlungen 145, 157–82.Google Scholar
Ring, U. & Layer, P. W. 2003. High-pressure metamorphism in the Aegean, eastern Mediterranean: Underplating and exhumation from the Late Cretaceous until the Miocene to Recent above the retreating Hellenic subduction zone. Tectonics 22 (3), doi:10.1029/2001TC001350, 23 pp.CrossRefGoogle Scholar
Ring, U., Layer, P. W. & Reischmann, T. 2001. Miocene high-pressure metamorphism in the Cyclades and Crete, Aegean Sea, Greece: Evidence for large-scale magnitude displacement on the Cretan detachment. Geology 29, 395–8.2.0.CO;2>CrossRefGoogle Scholar
Ring, U. & Reischmann, T. 2002. The weak and superfast Cretan detachment, Greece: exhumation at subduction rates in extruding wedges. Journal of the Geological Society, London 159, 225–8.Google Scholar
Rogers, G. & Hawkesworth, C. J. 1989. A geochemical traverse across the North Chilean Andes: evidence for crust generation from the mantle wedge. Earth and Planetary Science Letters 91, 271–85.CrossRefGoogle Scholar
Salemink, J. 1985. Skarn and ore formation at Seriphos, Greece. Geologica Ultraiectina 40, 1231.Google Scholar
Sánchez-Gómez, M., Avigad, D. & Heimann, A. 2002. Geochronology of clasts in allochthonous Miocene sedimentary sequences on Mykonos and Paros Islands: implications for back-arc extension in the Aegean Sea. Journal of the Geological Society, London 159, 4560.Google Scholar
Shaked, Y., Avigad, D. & Garfunkel, Z. 2000. Alpine high-pressure metamorphism at the Almyropotamos window (southern Evia, Greece). Geological Magazine 137, 367–80.CrossRefGoogle Scholar
Skarpelis, N. 2002. Geodynamics and evolution of the Miocene mineralization in the Cycladic–Pelagonian belt, Hellenides. Bulletin of the Geological Society of Greece 34 (6), 2191–206.Google Scholar
Skarpelis, N., Kyriakopoulos, K. & Villa, I. 1992. Occurrence and 40Ar/39Ar dating of a granite in Thera (Santorini, Greece). Geologische Rundschau 81, 729–35.Google Scholar
Skarpelis, N. & Liati, A. 1990. The prevolcanic basement of Thera at Athinios: Metamorphism, Plutonism and Mineralisation. In Thera and the Aegean World III, 2 (ed. Hardy, D. A.), pp. 172–82. London: The Thera Foundation.Google Scholar
Sun, S. S. & McDonough, W. F. 1989. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. In Magmatism in the Oceanic Basins (eds Saunders, A. D. & Norry, M. J.), pp. 313–45. Geological Society of London, Special Publication no. 42.Google Scholar
Tarney, J., Barr, S. R., Mitropoulos, P., Sideris, K., Katerinopoulos, A. & Stouraiti, C. 1998. Santorini: Geochemical constraints on magma sources and eruption mechanisms. In Proceedings 2nd Workshop: “The European Laboratory Volcanoes” (eds Casale, R., Fytikas, M., Sigvaldasson, G. & Vougioukalakis, G.), pp. 89111. Brussels: European Commission, Directorate-General Science.Google Scholar
Theodoropoulos, D. & Fytrolakis, N. 1974. Beitrag zur Kenntnis der Jungtectonik des Gebietes von Plaka bei Lavrion. Mining Metallurgical Annales 18, 2934.Google Scholar
Tomaschek, F., Kennedy, A. K., Villa, I. M., Lagos, M. & Ballhaus, C. 2003. Zircons from Syros, Cyclades, Greece – Recrystallization and mobilization of zircon during high-pressure metamorphism. Journal of Petrology 44, 19772002.CrossRefGoogle Scholar
Trotet, F., Vidal, O. & Jolivet, L. 2001. Exhumation of Syros and Sifnos metamorphic rocks (Cyclades, Greece). New constraints on the P–T paths. European Journal of Mineralogy 13, 901–20.CrossRefGoogle Scholar
Walcott, C. R. 1998. The Alpine evolution of Thessaly (NW Greece) and late Tertiary Aegean kinematics. Geologica Ultraiectina 162, 1176.Google Scholar
Wasserburg, G. J., Jacobsen, S. B., De Paolo, D. J., McCulloch, M. T. & Wen, T. 1981. Precise determination of Sm/Nd ratio, Sm, Nd isotopic abundances in standard solutions. Geochimica et Cosmochimica Acta 45, 2311–23.CrossRefGoogle Scholar
Wijbrans, J. R. & McDougall, I. 1988. Metamorphic evolution of the Attic–Cycladic Metamorphic Belt on Naxos (Cyclades, Greece) utilizing 40Ar/39Ar age spectrum measurements. Journal of Metamorphic Geology 6, 571–94.Google Scholar