Cold seeps along the main Marmara Fault in the Sea of Marmara (Turkey)
| Type | Article | ||||||||
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| Date | 2008-04 | ||||||||
| Language | English | ||||||||
| Author(s) | Zitter T1, Henry P1, Aloisi G2, Delaygue G1, Cagatay M3, de Lepinay B4, Al Samir M5, Fornacciari F1, Tesmer M5, Pekdeger A5, Wallmann K6, Lericolais Gilles 7 |
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| Affiliation(s) | 1 : Univ Aix Marseille 3, CEREGE, CNRS INSU, IRD,Coll France, F-13545 Aix En Provence 04, France. 2 : Univ Lyon 3, PEPS, CNRS INSU, Lyon, France. 3 : Istanbul Tech Univ, TR-80626 Istanbul, Turkey. 4 : Univ Nice, CNRS INSU, IRD, Nice, France. 5 : Free Univ Berlin, D-1000 Berlin, Germany. 6 : Res Ctr Marine Geosci, GEOMAR, Kiel, Germany. 7 : IFREMER, French Res Inst Exploitat Sea, F-29280 Brest, France. |
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| Source | Deep Sea Research Part I: Oceanographic Research Papers (0967-0637) (Elsevier), 2008-04 , Vol. 55 , N. 4 , P. 552-570 | ||||||||
| DOI | 10.1016/j.dsr.2008.01.002 | ||||||||
| WOS© Times Cited | 75 | ||||||||
| Keyword(s) | High permeability pathways, Fault scarp, Seafloor observations, Cold seeps, Sea of Marmara | ||||||||
| Abstract | The main Marmara Fault exhibits numerous sites of fluid venting, observed during previous cruises and in particular with R.O.V. VICTOR during the MARMARASCARPS cruise (2002). Long CALYPSO cores were recovered near active vents and at reference sites during the MARMARA-VT cruise (2004), together with echosounder sub-bottom profiles (frequency of 3.5kHz). We compiled R.O.V. video observations from MARMARASCARPS cruise and show that all known seeps occur in relationship with strike-slip faults, providing pathways for fluid migration. Among the main active sites, a distinction is made between gas seeps and water seeps. At gas seeps, bubble emissions at the seafloor or disturbed echofacies on sounder profiles demonstrate the presence of free methane gas at a shallow depth within the sediment. Most cores displayed gas-related expansion, most intense for cores taken within the gas plumes. On the other hand. authigenic carbonate chimneys characterize the water seeps and visible water outflow was observed at two sites (in the Tekirdag and Central basins). The pore fluid chemistry data show that the water expelled at these sites is brackish water trapped in the sediment during lacustrine times (before 14 cal kyr BP), in relation with the paleoceanography in the Sea of Marmara. The chimney site in the Tekirdag Basin is located at the outlet of a canyon feeding a buried fan with coarse sandy turbidites. Pore fluid composition profiles indicate that the sand layers channel the brackish fluids laterally from the basin into the fault zone at less than 20 m depth. However, a deeper gas source cannot be excluded. | ||||||||
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