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QUARTZ MEGACRYSTS IN GREECE: MINERALOGY AND ENVIRONMENT OF FORMATION

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V. Maneta, P. Voudouris
V. Maneta, P. Voudouris

Abstract


Quartz megacrysts in Greece are systematically sampled, described and classified with respect to their morphology, solid inclusion mineralogy, and geological conditions of formation. Quartz deposition took place due to reduction in silica solubility in the hydrothermal fluids in favourable geological environments such as: alpine-type fissures close to major detachment faults, skarns and quartz veins crosscutting and generally related to granitoids and, finally, epithermally altered volcanic rocks of Tertiary age. The varieties of coloured crystals (amethyst, smoky quartz, morion, green quartz, rock crystal), the twinning of the crystals, the mineralogy of solid phases included in quartz (rutile, chlorite, sericite, feldspars) as well as the types and forms of the crystals (Tessin habit, Muzo habit, faden quartz, sceptre, window quartz, interrupted crystals, double-terminated crystals, phantom quartz, gwindel quartz, etc.) give important information on the growth mechanisms and the physico-chemical conditions during quartz formation. The quartz crystals found in several localities are gemmy and their potential for use as gemstones should be evaluated.

Keywords


quartz; megacrysts; habits; solid inclusions; gemstones;

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References


Alfieris, D., 2006. Geological, geochemical and mineralogical studies of shallow submarine epithermal

mineralization in an emergent volcanic edifice, at Milos island (western side), Greece. PhD thesis,

Univ. Hamburg, 211pp.

Altherr, R., Kreuzer, H., Wendt, I., Lenz, H., Wagner, G., Keller, J., Harre, W., and Hohndorf, A., 1982.

A late Oligocene/Early Miocene High Temperature Belt in the Attic-Cycladic Crystalline Complex

(SE Pelagonian, Greece). Geol. Jb., 23, 97-164.

Cathelineau, M., 1988. Cation size occupancy in chlorites and illites as a function of temperature. Clay

Mineral 23, 471-485.

Dibble, H.L., 2002. Quartz: An introduction to crystalline quartz. Dibble Trust Fund Publ. NY USA, 100pp.

Dürr, S.T., Altherr R., Keller J., Okrusch M., and Seidel, E., 1978. The median Aegean crysralline belt:

Stratigraphy, Structure, Meramorphism, Magmatism. In Alps, Apennines, Hellenides, 455-477.

Gauthier, G., and Albandakis, N., 1991. Minerals from the Seriphos skarn, Greece. Miner. Record, 22(4), 303-308.

Henjes-Kunst, F., and Kreuzer, H., 1982. Isotopic dating of Pre-Alpidic rocks from the Island of Ios (Cyclades,

Greece). Contr. Miner. Petr. 80, 245-253.

Himmerkus, F., Reischmann, T., and Kostopoulos, D., K., 2006. Late Proterozoic and Silurian basement

units within the Servomacedonian Massif, northern Greece: the significance of terrane accretion in

the Hellenides. In: Robertson A.H.F. and D. Mountrakis (eds), Tectonic development of the Eastern

Mediterranean Region. Geol. Soc. London Special Publ., 260, pp. 35-50.

Iglseder, C., Grasemann B., Schneider, D.A., Petrakakis K., Miller, C., Klötzli, U.S., Thöni, M., Zámolyi,

A., and Rambousek, C., 2009. I and S-type plutonism on Seriphos (W-Cyclades, Greece). Tectonophysics,

, 69-83.

Jacobshagen, V., 1986. Geologie von Griechenland. Gebrüder Borntraeger, Berlin, Stuttgart, 363pp.

Jolivet L, Rimmelé G, Oberhänsli R, Goffé B, Candan O (2004) Correlation of syn-orogenic tectonic and

XLIII, No 2 – 695

metamorphic events in the Cyclades, the Lycian nappes and the Menderes massif. Geodynamic implications.

Bull Soc Géol Fr, 175, 217-238

Katzir, Y., Avigad, D., Matthews, A., Garfunkel, Z., and Evans, B.W., 2000. Origin, HP/LT metamorphism and

cooling of ophiolitic melanges in southern Evia (NW Cyclades), Greece. J. Metam. Geol., 18, 699-718.

Liati, A., 1986. Regional metamorphism and overprinting contact metamorphism of the Rhodope zone,

near Xanthi (N. Greece). Petrology, Geochemistry, Geochronology: Unpub. Ph.D. thesis, Univ. Braunschweig.

pp.

Lozios, S., 1993. Tectonic analysis of metamorphic formations of northeastern Attica. Unpubl. PhD thesis,

Univ. Athens, 299pp. (in Greek)

Maneta, V., (2007) Quartz in Greece: Crystal forms and environment of formation. Unpubl. Diploma thesis,

Univ. Athens, 149pp. (in Greek)

Mastrakas, N., 2006. Tinos pluton and associated skarn formations. Unpubl. PhD thesis, Univ. Patras, 227pp.

Melfos, V., 2005. Study of fluid inclusions in amethysts from areas of Macedonia and Thrace: Sapes,

Soufli, Nevrokopi. 2nd Congress of the Economic Geology Committee, Mineralogy & Petrology

(GSG), Thessaloniki, October 2005, 219-228. (in Greek)

Melfos, V., Vavelidis, M., Christofides, G., and Seidel, E., 2002. Origin and evolution of the Tertiary Maronia

porphyry copper-molybdenum deposit, Thrace, Greece. Mineral. Deposita 37, 648-668.

Mposkos, E., and Krohe, A., 2001. Structural evolution and exhumation history of the Rhodope UHP-HP

metamorphic province (Northern Greece). Bull. Geol. Soc. Greece, 34, 75-82.

Papanikolaou, D., and Panagopoulos, A., 1981. On the structural style of southern Rhodope. Geol. Balc.

, 13-22.

Pe-Piper, G., and Piper, D.J.W., 2002, The Igneous rocks of Greece. The anatomy of an orogene - Gebruder

Borntraeger, 30: 573pp.

Reischmann, T. and Kostopoulos, D. 2007. Terrane accretion in the Internal Hellenides. Geophysical

Reaserch abtracts, 9, 05337.

Rykart, R., 1995. Quarz-Monographie, Ott Verlag Thun, 461pp.

Salemink, J., 1980. On the Geology and Petrology of Serifos island (Cyclades, Greece). Ann. Geol. Pays

Hell., 30, 342-365, Utrecht, Nederlands.

Shaked Y., Avigad D., and Garfunkel, Z., 2000. Alpine high-pressure metamorphism at the Almyropotamos

window (southern Evia, Greece). Geol. Mag., 137, 367-380.

Tsolakos, A., Voudouris, P., and Papanikitas, A., 2008. Kristallklüfte in Attika and auf Euböa. Bergkristall,

Amethyst und Rauchquarz aus Griechenland. Lapis, 5. 36-39.

Voudouris, P., 2005. The minerals of Eastern Macedonia-Thrace: Geological setting and the potential of

geoconservation. GSG Congress, Samothraki, Bull. Geol. Soc. Greece 37, 62-77. (in Greek)

Voudouris, P., and Katerinopoulos, A., 2004. New occurences of mineral megacrysts in Tertiary magmatic-hydrothermal

and epithermal environments in Greece. Documenta Naturae, 151, 1-21.

Voudouris, P., Katerinopoulos, A., and Melfos, V., 2004a. Alpine-type fissure minerals in Greece, Documenta

Naturae, 151, 23-45.

Voudouris, V., Tsolakos, A., Papanikitas, A., and Solomos, C., 2004b. Nicht nur Micromounts. Neufunde

aus Lavrion 2003. Lapis 4, 13-15.

Voudouris, P., Katerinopoulos, A., Christofalou, F., and Kassimi, G., 2007. Serifos island, Aegean

Sea/Greece: a worldwide unique mineralogical and petrological geotope. ProGeo News, 1, 7-8.

Wawrzenitz, N., and Krohe, A., 1998, Exhumation and doming of the Thassos metamorphic core complex

(S Rhodope, Greece): structural and geochronological contrains. Tectonophysics, 285, 301-332.


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