FN Archimer Export Format
PT J
TI Gas occurrence and shallow conduit systems in the Western Sea of Marmara: a review and new acoustic evidence
BT 
AF SARITAS, Hakan
   CIFCI, Gunay
   GELI, Louis
   THOMAS, Yannick
   MARSSET, Bruno
   HENRY, Pierre
   GRALL, Celine
   ROCHAT, Alexis
AS 1:1;2:1;3:2;4:2;5:2;6:3;7:3;8:2;
FF 1:;2:;3:PDG-REM-GM-LAD;4:PDG-REM-GM-LAD;5:PDG-REM-GM-LAD;6:;7:;8:;
C1 Dokuz Eylul Univ, Inst Marine Sci & Technol, SeisLab, Izmir, Turkey.
   IFREMER, French Res Inst Explorat Sea, Marine Geosci, Plouzane, France.
   Aix Marseille Univ, CNRS, CEREGE, Marseille, France.
C2 UNIV DOKUZ EYLUL, TURKEY
   IFREMER, FRANCE
   UNIV AIX MARSEILLE, FRANCE
SI BREST
SE PDG-REM-GM-LAD
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-univ-france
   copubli-int-hors-europe
   copubli-sud
IF 1.94
TC 9
UR https://archimer.ifremer.fr/doc/00456/56737/58689.pdf
LA English
DT Article
CR MARMARASCARPS
   MARMESONET
   MARNAUT
   MARSITECRUISE
   VT 67 / MARMARA VT
BO L'Atalante
   Le Suroît
   Pourquoi pas ?
   Marion Dufresne
DE ;Shallow gas;Gas conduit systems;Mud volcano;Pockmark;2D-3D seismic;Western High;Sea of Marmara
AB Based on 3D and 2D high-resolution multichannel seismic reflection data in the Western High-Sea of Marmara, this study reviews shallow gas occurrence and related structures and classifies gas conduit systems within the upper, few hundred meter-thick sediment layers below the seafloor. Acoustic anomalies including high amplitude-reverse polarity reflections (bright spots), low amplitude transparent zones, chaotic or discontinuous reflections, pull-down effects, and plumes in the water column are interpreted in terms of natural gas occurrence and fluid flow structures (e.g., mud volcanoes, pockmarks). The gas occurrence is thought to be mostly of thermogenic origin. Mud volcanoes are one of the primary gas conduits forming craters on the seabed due to overpressure of fluidized gassy sediment flows. Following the reach of the Northern Branch of the North Anatolian Fault (NAF-N) to the Western High, the thermogenic fluids are believed to migrate vertically and horizontally to shallow depths mainly through the faults. Natural gas most probably originates from the Thrace Basin Eocene source rock or the Eocene-Oligocene reservoir rock, which extends below the Western High. Shallow gas is distributed by minor faults and gas pipes. Gas, to some extent, emanates from the seafloor via pockmarks and mud volcanoes or is trapped by the crests of the anticlines coinciding with erosional surfaces, impermeable sediments, and gas hydrate-bearing layers. Shallow traps below the tectonized “Western High” structure are likely located in thin layers of sands imbedded with impermeable silty clay layers. However, there is no shallow reservoir in the usual sense within the upper layers imaged by the 3D seismic data (< 300 ms two-way travel time). The existence of gas is an indicator of hydrocarbon-rich layers at depth and of active tectonics, and it also impacts the global climate and marine life conditions. 
PY 2018
PD OCT
SO Geo-marine Letters
SN 0276-0460
PU Springer
VL 38
IS 5
UT 000446101900001
BP 385
EP 402
DI 10.1007/s00367-018-0547-5
ID 56737
ER

EF