FN Archimer Export Format
PT J
TI Investigation on the geochemical dynamics of a hydrate-bearing pockmark in the Niger Delta
BT 
AF RUFFINE, Livio
   CAPRAIS, Jean-Claude
   BAYON, Germain
   RIBOULOT, Vincent
   DONVAL, Jean-Pierre
   ETOUBLEAU, Joel
   BIROT, Dominique
   PIGNET, Patricia
   RONGEMAILLE, Emmanuelle
   CHAZALLON, Bertrand
   GRIMAUD, Sylvie
   ADAMY, Jerome
   CHARLOU, Jean-Luc
   VOISSET, Michel
AS 1:1;2:2;3:1;4:1;5:1;6:1;7:1;8:2;9:1;10:3;11:4;12:4;13:1;14:1;
FF 1:PDG-REM-GM-LGM;2:PDG-REM-EEP-LEP;3:PDG-REM-GM-LGM;4:PDG-REM-GM-LES;5:PDG-REM-GM-LGM;6:PDG-REM-GM-LGM;7:PDG-REM-GM-LGM;8:PDG-REM-EEP-LMEE;9:PDG-REM-EEP-LMEE;10:;11:;12:;13:PDG-REM-GM-LGM;14:PDG-REM-GM-CTDI;
C1 IFREMER, Ctr Brest, Unite Rech Geosci Marines, F-29280 Plouzane, France.
   IFREMER, Ctr Brest, Unite Rech & Etud Environm Profonds, F-29280 Plouzane, France.
   Univ Lille 1, UMR CNRS 8523, CERLA FR CNRS 2416, Lab Phys Lasers Atomes & Mol PhLAM, F-59655 Villeneuve Dascq, France.
   TOTAL Oil Co, Pau, France.
C2 IFREMER, FRANCE
   IFREMER, FRANCE
   UNIV LILLE, FRANCE
   TOTAL, FRANCE
SI BREST
SE PDG-REM-GM-LGM
   PDG-REM-EEP-LEP
   PDG-REM-GM-LES
   PDG-REM-EEP-LMEE
   PDG-REM-GM-CTDI
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-univ-france
IF 2.469
TC 16
TU Centre national de la recherche scientifique
   Université Lille 1 - Sciences technologies
   Université du Littoral Côte d'Opale
UR https://archimer.ifremer.fr/doc/00139/24981/23102.pdf
LA English
DT Article
CR ERIG 3D
   NERIS 1
   NERIS 2
BO Pourquoi pas ?
   Le Suroît
   L'Atalante
DE ;Active pockmark;Anaerobic oxidation of methane;Gas hydrates;Carbonates;Seismic surveys;Fault system;U/Th dating
AB A joint industrial project with IFREMER and Total provides insights into the tectonic setting and the geochemistry of a large active pockmark offshore W-Africa in the Niger Delta. The study combines both geophysical (seismic) and geochemical data to infer the dynamics of a 300 m wide pockmark located at 667 m water depth. Two Calypso cores, one at the centre and one outside the pockmark, along with three box-cores, two inside the pockmark and one outside, were collected to study the geochemistry of gas hydrates, carbonates and pore waters. Two seismic lines, a 3D high resolution random line and a 2D high resolution seismic line, provide a good description of the plumbing of the system. The integrated results depict a very active pockmark characterized by several gas charged-bodies, a well identified BSR marking a hydrate accumulation zone, charged from deeper sources via a network of faults. Hydrates and carbonate concretions have been detected inside the pockmark while only the latter has been found outside. The hydrate analyses show that the hydrate-forming gases are of thermogenic origin, albeit overwhelmingly composed of methane. Pore-water analyses reveal the occurrence of anaerobic oxidation of methane coupled with sulphate reduction at shallow depth (∼200 cm). The chloride concentration profile exhibits both values lower than that of seawater which is inherent to hydrate dissociation after core recovery and positive anomalies (values 7% higher than that of seawater background) at the lowermost part of the core. The latter evidence suggests current or recent hydrate formation at this area. The carbonate dating provides additional temporal information and indicates that this pockmark has been active since ∼21 kyr.
PY 2013
PD MAY
SO Marine And Petroleum Geology
SN 0264-8172
PU Elsevier Sci Ltd
VL 43
UT 000318831400019
BP 297
EP 309
DI 10.1016/j.marpetgeo.2013.01.008
ID 24981
ER

EF