High-pressure rocks of Samos, Greece

Abstract

Summary The metamorphic complex of Samos is composed mainly of marbles and phyllites, typically with intercalations of serpentinites, meta-gabbros, blueschists, and greenschists. The meta-gabbros show typical flaser-structures, but contain frequent textural relics of the igneous protolith as well as relict clinopyroxene and brown hornblende. Primary plagioclase is totally replaced by albite, epidote or zoisite. Critical mineral assemblages of the Alpidic metamorphism are: albite + epidote + chlorite + glaucophane ± barroisite + sphene, albite + epidote + zoisite + tremolite + muscovite + sphene, albite + epidote + chlorite + tremolite ± barroisite ± muscovite ± calcite ± sphene. Associated glaucophanites show the following critical assemblages (+ sphene ± rutile): garnet + glaucophane + epidote ± barroisite + chlorite + muscovite ± paragonite, glaucophane + epidote + chlorite + muscovite + albite ± quartz. The major and trace element chemistry confirms that the metabasites are derived from abyssal tholeiites and related gabbros. The metapelites of Samos frequently contain chloritoid which, in the eastern part of the island, may be accompanied by kyanite, and rarely by Mg-carpholite. Meta-bauxites in eastern Samos contain diaspore, in western Samos diaspore + corundum (Mposkos 1978). At the peak of metamorphism temperatures may have reached about 420° and 470°C in east and in west Samos respectively, assuming elevated pressures of about 8 kbar.

Neotethyan closure history of western Anatolia: a geodynamic discussion

“…The Cycladic Blueschist Unit, as exposed in western Anatolia, is composed of the Selçuk Unit, which is a metamorphic ophiolitic mélange containing blocks of eclogitic metagabbro, serpentinite and marble, and the tectonically underlying Dilek Unit, which is an epidote-blueschist-facies metamorphosed sequence of Permian-Mesozoic neritic carbonate ( Fig. 4) (Okrusch et al 1984;Candan et al 1997;Ring et al 1999b;Cetinkaplan 2002). The Dilek Unit Gutnic et al (1979), Ş enel (1991), Collins and Robertson (1998), Soycan et al (2015).…”

Blueschists and Eclogites of the World and Their Exhumation

“…On the island of Samos, Okrusch et al (1984) described BS-to EA-facies metamorphic rocks, which were formed at 8 kbar and 420 to 470° C; a K-Ar date on hornblende yielded a Miocene age. Blueschist and eclogite sporadically occur on the island of Milos; they were identified as part of the basement, as xenoliths of Quaternary volcanic breccias, or as pebbles in Quaternary deposits.…”

Petrology of Fe‐Mg‐carpholite‐bearing metasediments from NE Oman

“…de * e-mail: scw2633@squ.edu t Present address. Roever, 1977;Mottana & Schreyer, 1977;Viswanathan & Seidel, 1979;Chopin & Goffk, 1981;Chopin & Schreyer, 1983;GoffC, 1984;Okrusch et al, 1985;GoffC et al, 1988;Theye et al, 1992;Vidal et al, 1992) which led to the realization that Fe-Mg carphoiites are restricted to high-pressure, low-temperature metamorphic terranes.…”