FN Archimer Export Format
PT J
TI Focused hydrocarbon-migration in shallow sediments of a pockmark cluster in the Niger Delta (Off Nigeria)
BT 
AF DE PRUNELE, Alexis
   RUFFINE, Livio
   RIBOULOT, Vincent
   PETERS, Carl A.
   CROGUENNEC, Claire
   GUYADER, Vivien
   PAPE, Thomas
   BOLLINGER, Claire
   BAYON, Germain
   CAPRAIS, Jean-Claude
   GERMAIN, Yoan
   DONVAL, Jean-Pierre
   MARSSET, Tania
   BOHRMANN, Gerhard
   GELI, Louis
   RABIU, Abdulkarim
   LESCANNE, Marc
   CAUQUIL, Eric
   SULTAN, Nabil
AS 1:1,2;2:1;3:1;4:3;5:1;6:1;7:3;8:2;9:1;10:4;11:1;12:1;13:1;14:3;15:1;16:5;17:6;18:6;19:1;
FF 1:PDG-REM-GM-LCG;2:PDG-REM-GM-LCG;3:PDG-REM-GM-LAD;4:;5:PDG-REM-GM-LGM;6:PDG-REM-GM-LCG;7:;8:;9:PDG-REM-GM-LGS;10:PDG-REM-EEP-LEP;11:PDG-REM-GM-LCG;12:PDG-REM-GM-LCG;13:PDG-REM-GM-LGS;14:;15:PDG-REM-GM-LAD;16:;17:;18:;19:PDG-REM-GM;
C1 IFREMER, Dept Ressources Phys & Ecosyst Fond Mer REM, Unite Geosci Marines, Plouzane, France.
   Inst Europeen Mer IUEM, Ecole Doctorale Sci Mer, Plouzane, France.
   MARUM Ctr Marine Environm Sci, Leobener Str, Bremen, Germany.
   IFREMER, Dept Ressources Phys & Ecosyst Fond Mer REM, Unite Ecosyst Profonds, Plouzane, France.
   Nigeria Inst Oceanog & Marine Res, Lagos, Nigeria.
   TOTAL Explorat Prod, Pau, France.
C2 IFREMER, FRANCE
   UBO, FRANCE
   UNIV BREMEN MARUM, GERMANY
   IFREMER, FRANCE
   NIOMR, NIGERIA
   TOTAL, FRANCE
SI BREST
SE PDG-REM-GM-LCG
   PDG-REM-GM-LAD
   PDG-REM-GM-LGM
   PDG-REM-GM-LGS
   PDG-REM-EEP-LEP
   PDG-REM-GM
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-europe
   copubli-univ-france
   copubli-int-hors-europe
   copubli-sud
IF 2.981
TC 24
UR https://archimer.ifremer.fr/doc/00365/47647/47676.pdf
   https://archimer.ifremer.fr/doc/00365/47647/47677.pdf
LA English
DT Article
CR ERIG 3D
   GUINECO-MEBO
   NERIS 1
   NERIS 2
BO Pourquoi pas ?
   Le Suroît
   L'Atalante
DE ;anaerobic oxidation of methane;cluster of pockmarks;fluid flow;gas hydrates;pore-water profiles;transient state
AB The Niger Delta is one of the largest hydrocarbon basin offshore Africa and it is well known for the presence of active pockmarks on the seabed. During the Guineco-MeBo cruise in 2011, long cores were taken from a pockmark cluster in order to investigate the state of its current activity. Gas hydrates, oil and pore-water were sampled for geochemical studies.  The resulting dataset combined with seismic data reveal that shallow hydrocarbon migration in the upper sedimentary section was focused exclusively within the pockmarks. There is a clear tendency for gas migration within the hydrate-bearing pockmarks, and oil migration within the carbonate-rich one. This trend is interpreted as a consequence of hydrate dissolution followed by carbonate precipitation in the course of the evolution of these pockmarks. We also demonstrate that Anaerobic Oxidation of Methane (AOM) is the main process responsible for the depletion of pore-water sulfate, with depths of the Sulfate-Methane Transition Zone (SMTZ) ranging between 1.8 and 33.4 m. In addition, a numerical transport-reaction model was used to estimate the age of hydrate-layer formation from the present-day sulfate profiles. The results show that the sampled hydrate-layers were formed between 21 and 3750 years before present.  Overall, this work shows the importance of fluid flow on the dynamics of pockmarks, and the investigated cluster offers new opportunities for future cross-site comparison studies. Our results imply that sudden discharges of gas can create hydrate layers within the upper sedimentary column which can affect the seafloor morphology over few decades.
PY 2017
PD JAN
SO Geochemistry Geophysics Geosystems
SN 1525-2027
PU Amer Geophysical Union
VL 18
IS 1
UT 000395186600006
BP 93
EP 112
DI 10.1002/2016GC006554
ID 47647
ER

EF