INSIGHTS INTO HYDROTHERMAL ACTIVITY IN THE ITI OPHIOLITE (CENTRAL GREECE)


Δημοσιευμένα: Jan 1, 2010
S. Karipi
B. Tsikouras
I. Rigopoulos
K. Hatzipanagiotou
P. Pomonis
Περίληψη

Scarce intensely epidotised doleritic dykes, up to 1.5 m thick, penetrate in sharp contact serpentinised peridotites of the remnant ophiolite nappe of the Iti ophiolite. They are generally whitish rocks characterised by distinct and irregularly distributed, olive-green areas within the rock mass. Petrographic evidence reveals that their assemblage is dominated by quartz and epidote. Albite, chlorite and titanite occur as accessory phases. Minor opaque minerals are represented by magnetite, pyrite and chalcopyrite, as well as relic Cr spinel,. The mineral assemblage of the studied rocks comprises replacement products of the original phases under greenschist facies conditions. Moreover, the almost
exclusive bi-mineralic (quartz + epidote) assemblage of the altered doleritic rocks, as well as obliteration of the original doleritic textures imply extensive recrystallisation, controlled by hydrothermal circulation. The compositions of the phases in these dykes mark the most alteration-resistant chemical components that have the potential to remain in their original associations, during such extensive recrystallisation.

Λεπτομέρειες άρθρου
  • Ενότητα
  • Πετρολογία και Ορυκτολογία
Λήψεις
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Αναφορές
Alexander, R.J., Harper, G.D., and Bowman, J.R., 1993. Oceanic faulting and fault-controlled subseafloor
hydrothermal alteration in the sheeted dike complex of the Josephine Ophiolite, Journal of Geophysical
Research, 98, 9731–9759.
Alt, J.C., 1995. Subseafloor processes in mid-ocean ridge hydrothermal systems. In S. Humphris, J. Lupton,
L. Mullineaux and R. Zierenberg (eds.), Seafloor Hydrothermal System: Physical, Chemical, Biological
and Geological Interpretation. Geophysical Monograph, 91, 85-114. Amerian Geophysical
Union, Washington D. C.
Banerjee, N.R., and Gillis, K.M., 2001. Hydrothermal alteration in a modern suprasubduction zone: The
Tonga forearc crust, Journal of Geophysical Research, 21, 737-750.
Banerjee, N.R., Gillis, K.M., and Muehlenbachs, K., 2000. Discovery of epidosites in a modern oceanic
XLIII, No 5 – 2622
setting, the Tonga forearc, Geology, 28(2), 151-154.
Bettison-Varga, L., Varga, R.J., and Schiffman, P., 1992. Relation between ore-forming hydrothermal
systems and extensional deformation in the Solea graben spreading center, Troodos ophiolite, Cyprus,
Geology, 20, 987-990.
Bird, D.K., and Spieler, A.R. 2004. Epidote in Geothermal Systems, Reviews in Mineralogy and Geochemistry,
(1), 235-300.
Cann, J., and Gillis, K., 2004. Hydrothermal insights from the Troodos ophiolite, Cyprus. In E.E. Davis
and H. Elderfield (eds.), Hydrogeology of the Oceanic Lithosphere. 274-310, Cambridge University
Press.
Celet, P., 1962. Contribution à l’étude géologique du Parnasse-Kiona et d’une partie des regions méridionales
de la Grèce continentale, Annalles Géologiques des Pays Helléniques, 13, 446pp.
Celet, P., 1976. À propos du mélange de type “volcano-sédimentaire” de l’Iti (Grèce méridionale), Bulletin
de la Société Géologique de France, 18, 299-307.
Celet, P., Ferrière, J., and Wigniolle, E., 1977. Le problème de l’origine des blocs exogènes du mélange
à elements ophiolitiques au Sud du Sperchios et dans le massif de l’Othrys (Grèce), Bulletin de la Société
Géologique de France, 19(4), 935-942.
Cowan, J.G., 1989. Geochemistry of reaction zone source rocks and black smoker fluids in the Troodos
ophiolite, Ph.D. Thesis, University of Newcastle-upon-Tyne.
Gillis, K.M., 2002. Root-zones of a fossil oceanic hydrothermal system exposed in the Troodos Ophiolite,
The Journal of Geology, 110, 57-74.
Harper, G.D., Bowman, J.R, and Kuhns, R.J., 1988. A field, chemical, and stable isotope study of subseafloor
metamorphism of the Josephine Ophiolite, California-Oregon, Journal of Geophysical Research,
, 4625-4656.
Hey, M.H., 1954. A new review on the chlorites, Mineralogical Magazine, 224, 277-298.
Honnorez, J.J., Alt, J.C., and Humphris, S.E., 1998. Vivisection and autopsy of active and fossil hydrothermal
alterations of basalt beneath and within the TAG hydrothermal mound. In P.M. Herzig, S.E.
Humphris, D.J. Miller and R.A. Zierenberg (eds.), Proceedings of the Ocean Drilling Program, Scientific
Results, Vol. 158.
Jowitt, S.M., Jenkin, G.R., Coogan, L.A., Naden, J., and Chenery, S.R.N., 2007.
Epidosites of the Troodos Ophiolite: A direct link between alteration of dykes and release of base
metals into ore-forming hydrothermal systems? 9th Biennial SGA Meeting, Mineral Exploration and
Research: Digging Deeper, 20th – 23rd August 2007.
Karipi, S., 2004. The ophiolitic outcrops of Iti and Kallidromon. Geological study – Petrogenetic evolution
– Geotectonic interpretation, Ph.D. Thesis, University of Patras, 417pp.
Karipi, S., Tsikouras, B., and Hatzipanagiotou, K., 2006. The petrogenesis and tectonic setting of ultramafic
rocks from Iti and Kallidromon Mountains, continental Central Greece: vestiges of the Pindos
ocean, Canadian Mineralogist, 44(1), 267-287.
Karipi, S., Tsikouras, B., Pomonis, P., and Hatzipanagiotou, K., 2008. Geological evolution of the Iti and
Kallidromon Mountains (central Greece), focused on the ophiolitic outcrops, Zeitschrift der Deutschen
Gesellschaft für Geowissenschaften, 159(3), 549-563.
Lister, C.R.B., 1974. On the penetration of water into hot rock, Geophysical Journal of Royal Astronomical
Society, 39, 465-509.
Mevel, C., and Cannat, M., 1991. Lithospheric streching and hydrothermal processes in oceanic gabbros
from slowspreading ridges. In Tj. Peters et al. (ed.), Ophiolite Genesis and Evolution of the Oceanic
Lithosphere, Ministry of Petroleum and Minerals, Sultanate of Oman, 293-312.
XLIII, No 5 – 2623
Muehlenbachs, K., Banerjee, N.R., Dilek,Y., Furnes, H., and Shallo, M., 2004. Seafloor hydrothermal alteration
of the crustal sequence of the Mirdita ophiolite, Albania. 32nd International Geological Congress,
Florence, Italy, 20-28/8/2004.
Nehlig, P., Juteau, T., Bendel, V., and Cotten, J., 1994. The rootzones of oceanic hydrothermal systems:
constraints from the Samail ophiolite (Oman), Journal of Geophysical Research, 99, 4703–4713.
Papanikolaou, D., 1989. Are the medial crystalline massifs of the Eastern Mediterranean drifted Godwanian
fragments?, Geological Society of Greece, Special Publication, 1, 63-90.
Richardson, C.J., Cann, J.R., Richards, H.G., and Cowan, J.G., 1987. Metal-depleted root zones of the
Troodos ore-forming hydrothermal systems, Cyprus, Earth and Planetary Science Letters, 84, 243–
Richter, D., Mihm, A., and Müller, C., 1997. Die pelagonischen Deckenreste auf dem Flysch des Ostpindos-
Synklinoriums (Pindos-Zone) westlich des Iti-Gebirges (Mittelgriechenland), Zeitschrift der
Deutschen Geologischen Gesellschaft, 148(2), 237-246.
Schiffman, P., 1995. Low grade metamorphism of mafic rocks. Geological Society of America, Special
Paper 296.
Schiffman, P., Bettison, L.A., and Smith, B.M., 1990. Mineralogy and geochemistry of epidosites from
the Solea graben, Troodos ophiolite, Cyprus. In J. Malpas, E. Moores, A. Panayiotou, and C.
Xenophontos (eds.), Ophiolites: Oceanic Crustal Analogues. Nicosia: Cyprus Geological Survey Department,
pp. 673–684.
Schiffman, P., and Smith, B.M., 1988. Petrology and oxygen isotope geochemistry of a fossil seawater
hydrothermal system within the Solea Graben, Northern Troodos Ophiolite, Cyprus, Journal of Geophysical
Research, 93, 4612-4624.
Schiffman, P., Smith, B.M., Varga, R.J., and Moores, E.M., 1987. Geometry, conditions, and timing of offaxis
hydrothermal metamorphism and ore-deposition in the Solea Graben, Nature, 325, 423-425.
Stakes, D.S., and Taylor, H.P., 1992. The Northern Semail Ophiolite: an oxygen isotope, microprobe and
field study, Journal of Geophysical Research, 97(7), 43-80.
Stampfli, G.M., 1996. The Intra-Alpine terrain: A Paleotethyan remnant in the Alpine Variscides, Eclogae
Geologicae Helveticae, 89(1), 13-42.
Stampfli, G.M., Mosar, J., De Bono, A., and Vavassis, I., 1998. Late Paleozoic, Early Mesozoic Plate
Tectonics of the Western Tethys, Geological Society of Greece, Special Publication, Bulletin of the
Geological Society of Greece, 32(1), 113-120.
Valsami, E., 1990. Geochemistry and petrology of hydrothermal discharge zones in the Pindos and Othris
ophiolites, Greece, Ph.D. Thesis, University of Newcastle upon Tyne, 359pp.
Valsami, E., and Cann, J.R., 1992. Evidence for the mobility of the rare earth elements in zones of intense
hydrothermal alteration in the Pindos ophiolite, Greece. In L.M. Parson, B.J. Murton, and P. Browning
(eds.), Ophiolites and Their Modern Oceanic Analogues, Geological Society of London, Special
Publication, 60, 219-232.
Valsami-Jones, E., and Cann, J.R., 1994. Controls on the Sr and Nd isotopic compositions of hydrothermally
altered rocks from the Pindos ophiolite, Greece, Earth Planetary Science Letters, 125, 39-54.
Valsami-Jones, E., and Ragnarsdóttir, K.V., 1997. Controls on uranium and thorium behaviour in oceanfloor
hydrothermal systems: examples from the Pindos ophiolite, Greece, Chemical Geology, 135,
-274.
Wigniolle, E., 1977. Données nouvelles sur la géologie du massif de l’Iti (Grèce continentale), Annalles
de la Société Géologique du Nord, 47(3), 239-251.
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