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Blueschist-to-Greenschist Transition and the P-T Path of Prasinites from the Lavrion Area, Greece

Published online by Cambridge University Press:  05 July 2018

Emmanuel Baltatzis
Emmanuel Baltatzis*
Affiliation:
National University of Athens, Department of Geology, Panepistimiopolis-Ano Ilissia, Athens 15784, Greece
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Abstract

The Lavrion area is part of the Attic-Cycladic massif. Blue amphibole analyses revealed that they are glaucophane or ferroglaucophane. Ca-amphiboles are characterized as actinolite or actinolitic hornblende. The Ps component of epidotes from the glaucophane-bearing rocks varies from 25.42–30.89%, whereas the Ps component of epidotes from the greenschist assemblages ranges from 23.81–26.88%. Chlorites show narrow compositional variations of ferromagnesian ratios (Xmg=0.48–0.53). Albites are almost pure Ab100. The Kfeldspar present has a low Ab content. The evolution of the prasinites studied is characterized by the progressive transformation of eclogite facies (?) rocks through epidote blueschists into greenschists. A P-T path for the prasinites is presented indicating epidote blueschist facies at P-T conditions of around 7.0–7.5 kbar and 300–340°C. Pressures of 4.0–4.5 kbar and temperatures around 340–360°C are estimated for the subsequent overprint in the greenschist facies. The path EBS to GS conditions followed under nearly isothermal uplift.

Keywords

blueschistgreenschistprasiniteP-T pathLavrionGreece
Type
Petrology
Information
Mineralogical Magazine , Volume 60 , Issue 401 , August 1996 , pp. 551 - 561
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1996

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References

Altherr, R., Schliestedt, M., Okrush, M., Seidel, E., Krenzer, H., Harre, W., Lenz, H., Wendt, I. and Wagner, G.A. (1979) Geochronology of high- pressure rocks on Sifnos (Cyclades, Greece). Contrib. Mineral. Petrol., 70, 245–55.CrossRefGoogle Scholar
Altherr, R., Krenzer, M., Wendt, I., Lenz, H., Wagner, G.A., Keller, J., Harre, W. and Hohndozf, A. (1982) A late Oligocene / Early Miocene high temperature belt in the Attic - Cycladic Crystalline Complex (SE Pelagonian, Greece). Geol Jahrb. E23, 97–164.Google Scholar
Andriessen, P.A.M., Boetzijk, N.A.I., Hebeda, E.H., Priem, H.N.A., Verdurmen, E.A.Th. and Verschure, R.H. (1979) Dating the events of metamorphism and granitic magmatism in the Alpine Orogen of Naxos (Cyclades, Greece). Contrib. Mineral. Petrol, 69, 215–25.CrossRefGoogle Scholar
Avigad, D. and Garfunkel, Z. (1991) Uplift and exhumation of high-pressure metamorphic terrains: the example of the Cycladic blueschist belt (Aegean sea). Tectonophys., 188, 357–72.CrossRefGoogle Scholar
Avigad, D., Matthews, A., Evans, B.W. and Garfunkel, Z (1992) Cooling during the exhumation of a blueschist terrane: Sifnos (Cyclades, Greece). Eur. J. Mineral., 4, 619–34.CrossRefGoogle Scholar
Baltatzis, E. (1981) Contact metamorphism of a calc- silicate hornfels from Plaka area, Lavrium, Greece. Neus. Jahrb. Mineral, Mh., 481—8.Google Scholar
Bröcker, M. (1990) Blueschist-to-greenschist transition in the metabasites from Tinos island, Cyclades, Greece: Compositional control of fluid infiltration? Lithos, 25, 25–39.CrossRefGoogle Scholar
Brown, E.H. (1977) The crossite content of a Ca- amphibole as a guide to pressure of metamorphism. J. Petrol, 18, 53–72.CrossRefGoogle Scholar
Brown, E.H. (1986) Geology of the Shuksan Suite, North Cascades, Washington, U.S.A. Geol. Soc. Amer. Bull., 164, 143–54.Google Scholar
Brown, G.C., Hughes, D.J. and Esson, J. (1973) New XRF data retrieval techniques and their applications to U.S.G.S standard rocks. Chem. GeoL, 11, 223–9.CrossRefGoogle Scholar
Dunham, A.C. and Wilkinson, F.C.F. (1978) Accuracy precision and detection limits of energy-dispersire eJectron-microprobe analyses of silicates. X-ray spectrometry, 7, 50–6.CrossRefGoogle Scholar
Dürr, St., Altherr, R., Keller, J., Okrusch, M. and Seidel, E. (1978) The Median Aegean Crystalline belt: Stratigraphy, structure, metamorphism magmatism. In: Alps, Apennines, Hellenides (Closs, H., Roeder, D.H., and Schmidt, K., eds.) Schweizerbart, Stuttgart.Google Scholar
Evans, B.W. (1990) Phase relations of epidote- blueschists. Lithos, 25, 3 —23.CrossRefGoogle Scholar
Kessel, G. (1990) Untersuchungen zu deformation and metamorphose in Attischen Kristallin, Griechenland. Berliner geowiss. Abh. A. 126, p. 120.Google Scholar
Leake, B.E. (1978) Nomenclature of amphiboles. Amer. Mineral, 63, 1023–52.Google Scholar
Lepsius, R. (1893) Geologie von Attika Berlin, 196 pp.Google Scholar
Marinos, E.P. and Petrascheck, W.E. (1956) Lavrium. Geol. Geophys. Res.y 4, 242 pp.Google Scholar
Meschede, M. (1986) A method of discriminating between different types of mid-ocean ridge basalt and continental tholeiites with the Nb-Zr-Y diagram. Chem. Geol., 56, 207–18.CrossRefGoogle Scholar
Moore, D.E. (1984) Metamorphic history of a high- grade blueschist exotic block from the Franciscan Complex, California. J. Petrol., 25, 126–50.CrossRefGoogle Scholar
Mullen, E.D. (1983) MnO/TiO2—P2O5: a minor element discriminant for basaltic rocks of oceanic environments and its implications for petrogenesis. Earth Planet. Sci. Lett., 62, 53–62.CrossRefGoogle Scholar
Pearce, J.A. (1983) Role of the sub-continental lithosphere in magma genesis at actine continental margins. In: Continental basalts and mantle xenoliths. (Hawkesworth, C.J. and Norry, M.J., eds.) Shiva, Nantwich, 230—49.Google Scholar
Salemink, J. (1985) Skarn and ore formation at Serifos, Greece, as a consequence of granodiorite intrusion. Geologica Ultrajectina, 40, 232 pp.Google Scholar
Schliestdedt, M. (1986) Eclogite-blueschist relationships as evidenced by mineral equilibria in the high-pressure rocks of Sifnos (Cyclades, Greece). J. Petrol, 27, 1437–59.CrossRefGoogle Scholar
Schiestedt, M., Altherr, R. and Matthews, A. (1987) Evolution of the Crystalline complex: petrology, isotope, geochemistry and geochronology. In: Chemical Transport in Metasomatic Processes. (Helgeson, H. C., ed.) Reidel Publishing Company.Google Scholar
Schliestedt, M., Bartsch, V., Carl, M., Matthews, A. and Henjes-Kunst, F. (1994) The P-T path of greenschist facies rocks from the island of Kithnos (Cyclades, Greece). Chem. Erde, 54, 281–96.Google Scholar
Stormer, J.C.Fr. (1975) A practical two-feldspar geothermometer. Amer. Mineral., 60, 667–74.Google Scholar
Triboulet, C. (1992) The (Na-Ca) amphibole-albite- chlorite-epidote-quarta gcothermobarometers in the system S-A-F-M-C-N-H2O). 1. An empirical calibration. 2. Applications to metabasic rocks in different metamorphic setting. J. Metam. Geol., 10, 545–56.and 557-66.CrossRefGoogle Scholar