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EVIDENCE OF COLD SEEPING IN PLIO-PLEISTOCENE SEDIMENTS OF SE PELOPONESE: THE FOSSIL CARBONATE CHIMNEYS OF NEAPOLIS REGION

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D. Sakellariou, I. Fountoulis, V. Lykousis
D. Sakellariou, I. Fountoulis, V. Lykousis

Abstract


Unique, upright standing, chimney-like structures outcropping in (Plio-)Pleistocene sediments of Neapolis region, SE Peloponese are studied thoroughly. The up to 5m high and 3m wide structures, previously interpreted either as “rhizoliths” or hypercalcified giant sponges or fossilized palm trees, display a wide range of morphological types and are composed of hard, several cm thick, carbonate tube. Their orifice is filled up with muddy, sandy or fine conglomerate material, which reflects the sedimentary nature of the surrounding formation, and is penetrated by numerous whitish, mm-thin, carbonate veins. Their formation and spatial occurrence is genetically associated with two intersecting systems of diaclases/fractures, also sealed with carbonate material. We interpret these structures as non-volcanic, fossil, gas chimneys, related to cold seeping (biogenic methane? seeping). The intersecting diaclases have been used as conduits for the upward fluid migration, thus, the gas seeping process must have taken place after the diagenesis of the host sedimentary formations. The impressive outcrops of carbonate gas chimneys in the Neapolis region is the first evident of cold seeping, eventually related with mud volcanism, in the Plio-Pleistocene sedimentary basins of the Hellenic Forearc.

Keywords


non-volcanic gas chimneys; cold seeping; diaclases/fractures; Hellenic Forearc;

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References


De Boever, E., Swennen, R. and Dimitrov, l., 2006. Lower Eocene carbonate cemented chimneys (Varna,

NE Bulgaria): Formation mechanisms and the (a) biological mediation of chimney growth? Sedimentary

Geology 185, 159–173.

Diaz-del-Rio, V., Somoza, L., Martinez-Frias, J., Mata, M.P., Delgado, A., Hernandez-Molina, F.J., Lunar,

R., Martin-Rubi, J.A., Maestro, A., Fernandez-Puga, M.C., Leon, R., Llave, E., Medialdea, T.,

Vazquez, J.T., 2003. Vast fields of hydrocarbon-derived carbonate chimneys related to the accretionary

wedge/olistostrome of the Gulf of Cadiz. Marine Geology, 195, 177-200.

Georgiades-Dikeoulia, E., Symeonides, N. & Giannopoulos V., 2000. A unique outcrop of large-size

sponges in the SE Peloponnesus (Lakonia district). Geol. Soc. Greece, Sp. Publ, No 9, 95-100.

Hovland, M., & Judd, A. G. 1988. Seabed pockmarks and seepages: Impact on geology, biology and the

marine environment. London: Graham and Trotman, 293 p.

Gerolymatos, I., 1999. Geological Map of Greece, scale 1:50.000, Neapolis – Ag. Nikolaos Sheet IGME 1999.

Kopf, A., Klaeschen, D., Mascle, J. 2001. Extreme efficiency of mud volcanism in dewatering accretionary

prisms. Earth and Planetary Science Letters, 189, 295-313.

Kowalczyk, G. & Winter K-P., 1991. Roehren- und saeulenfoermige Strukturen in jungen Sedimenten

Suedost-Lakoniens (Peloponnes, Griechenland). Geol. Inst. Univ. Koeln, Sonderveroeffentlichungen

No 82, 423-431.

Kowalczyk, G., Winter, K-P., Steinich, G. & Reisch, L., 1992. Jungpleistozaene Strandterrassen in Suedost-Lakonien

(Peloponnes, Griechenland). Schriftenr. F. Geowiss., 1(1), 1-72, Berlin.

Lekkas, S., Alexopoulos, A. and Danamos, G., 1995. Neotectonic map of Greece, 1 :100. 000, GythioNeapolis

sheet. Publ. by: European Centre on Prevention and Forecasting of Earthquakes, Earthquake

Planning and Protection Organization, Tectonic Committee of the Geological Society of

Greece, Athens.

Loncke, L., Mascle, J., Fanil Scientific Parties, 2004. Mud volcanoes, gas chimneys, pockmarks and mounds

in the Nile deep-sea fan (Eastern Mediterranean): geophysical evidences. Marine Geology 21, 669-689.

Lykousis, V., Alexandri, S., Woodside, J., Nomikou, P., Perissoratis, C., Sakellariou, D., de Lange, G.,

Dahlmann, A., Casas, D., Rousakis, G., Ballas, D. & Ioakim, Ch., 2005. New evidence of extensive

active mud volcanism in the Anaximander mountains (Eastern Mediterranean): The ‘‘ATHINA’’ mud

volcano. Environmental Geology 46:1030–1037.

Mascle, J., Sakellariou, D., and participants of the 29th CIESM Workshop, 2006. Executive Summary. In:

CIESM Workshop Monographs 29, 2006, Fluid seepages / mud volcanism in the Mediterranean and

adjacent domains.

Sakellariou, D., Fountoulis, I. and Lykousis, V., 2007. Fossil carbonate chimneys discovered in Lower

Pleistocene marine sediments of Southern Peloponnese, Greece. In: Proceedings 38th CIESM, Congress,

-13 April 2007, Istanbul.


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