FLUID INCLUSION STUDY IN ALPINOTYPE QUARTZ CRYSTALS FROM FISSURES IN PENTELICON MOUNTAIN


Σ. Κίλιας
Π. Βουδούρης
Α. Κατερινόπουλος
Σ. Καβούρη
Abstract

Idiomorphic quartz crystals, up to 50 cm long, have been developed on massive, milky quartz substrate, within veins hosted by orthogneisses of the polymetamorphic system of the Pentelikon Mt. The veins fill NE-SW or/and NW-SE trending en-echelon fissures associated with the DfP deformation phase of Alpine age. Quartz-hosted fluid inclusions have been studied in order to decipher the physicochemical conditions of deposition and the relationship to the geotectonic evolution of the area. Homogenization temperatures (Th) to the liquid phase range between 175 and 240 °C clustering at 180-200 °C. Final ice melting temperatures (Tmjce) range between -0.1 and -14.5 °C corresponding to salinities between 0.2 and 23 wt% NaCI equiv. in the system HìO-NaCI. Thsalinity relationships indicate quartz crystallization under boiling conditions at temperatures 150-220 °C and pressures <1.5 Kbar. The results of this study indicate that quartz was deposited from hydrothermal fluids with a meteoric water component in the latest stages of retrograde metamorphism and regional decompressive uplift of the Pentelicon Mt metamorphic complex

Article Details
  • Section
  • Petrology
Downloads
Download data is not yet available.
References
Κατσικάτσος Γ. 2002. Γεωλογικός Χάρτης της Ελλάδας σε κλίμακα 1:50000. Φύλλο «Κηφισιά». Εκδ. Ι.Γ.Μ.Ε., Αθήνα 2002.
Λόζιος Σ.Γ. 1993. Τεκτονική ανάλυση μεταμορφωμένων σχηματισμών Β.Α. Απικής. Διδακτορική Διατριβή, Αθήνα, 301σ.
Μαριολάκος Η. &ι Παπανικολάου Δ. 1973. Παρατηρήσεις επί την τεκτονική του δυτικού Πεντελικού - Αττική. Δελτ.Ελλ.Γεωλ.Εταιρ., Χ/2, 134-197
Bodnar R.J. 1993. Revised equation and table for determing the freezing point depression of H20-NaCI solutions. Geoch. Cosm. Acta, 57, ρ 683-684
Boiron M.C., Cathelineau, M., Banks, DA, Fourcade, S. & Vallance, J. 2003. Mixing of metamorphic and surficial fluids during the uplift of the Hercynian upper crust: consequences for gold deposition. Chem. Geol. 194 ρ 119-141
Hedenquist J.W. & Henley R.W. 1985. The importance of C02 freezing point measurements of fluid inclusions: evidence for geothermal systems and implications for epithermal ore depositions. Econ. Geol. 80, p1379- 1406
Kessel 1990. Untersuchungen zu Deformation und Metamorphose im Attischen Kristallin, Griechenland, Diss. Univ. Berlin, 120p.
Kilias S. 2001. Genesis of vein-quartz deposits in relation to uplift of the Serbo-macedonian Zone, N. Greece. Evidence from fluid inclusions studies. Chemie der Erde, 61, pi 17-139
Mullis, J., Dubessy, J., Poty, B. & O'Neil J. 1994. Fluids regimes during late stages of a continental collision. Physical, chemical and stable isotope measurements of fluid inclusions in fissure quartz from a geotraverse through the Central Alps. Switzerland. Geoch. Cosm. Acta, 58 (10), pp 2239-2267.
Nesbitt B.E. & Muelenbachs K. 1995. Geochemical studies of the origins and effects of synorogenetic fluids in the southern Omineca ;rystalline belt of British Columbia, Canada. Geol. Soc. Amer. Bull. 107, p1033-1050
Niedermayr G., 1993. Alpine kluefte. Miner. Welt, 4/6, p57-69
Roedder E. 1984. Fluid inclusions. Rev. Min. 12, 644p.
Vityk M. O., Bodnar R.J. & Dudok I.V. 1995. Natural and synthetic re-equilibration textures of fluid inclusions in quartz (Marmarosh Diamonds): Evidence for refilling under condition of compressive loading. Eur. J. Mineral. 7, p1071-1087.
Zhang Y.G. & Frantz J.D. 1987. Determination of the homogenization temperatures and densities of supercritical fluids in the system NaCL-KCI-CaCI2-H20 using synthetic fluids inclusions. Chem. Geol., 64, ρ 335-350.
Most read articles by the same author(s)