FN Archimer Export Format
PT J
TI Fluid seepage associated with slope destabilization along the Zambezi margin (Mozambique)
BT 
AF Deville, Eric
   Scalabrin, Carla
   Jouet, Gwenael
   Cattaneo, Antonio
   Battani, Anne
   Noirez, Sonia
   Vermesse, Hélène
   Olu, Karine
   Corbari, Laure
   Boulard, Marion
   Marsset, Tania
   Dall'Asta, Massimo
   Torelli, Martina
   Pastor, Lucie
   Pierre, Delphine
   Loubrieu, Benoit
AS 1:1;2:2;3:2;4:2;5:1;6:1;7:1;8:3;9:4;10:3;11:2;12:5;13:1;14:3;15:2;16:2;
FF 1:;2:PDG-REM-GM-LCG;3:PDG-REM-GM-LGS;4:PDG-REM-GM-LAD;5:;6:;7:;8:PDG-REM-EEP-LEP;9:;10:PDG-REM-EEP-LEP;11:PDG-REM-GM-LGS;12:;13:;14:PDG-REM-EEP-LEP;15:PDG-REM-GM-CTDI;16:PDG-REM-GM-CTDI;
C1 IFP-Energies Nouvelles, Rueil-Malmaison, France
   IFREMER, Géoscience Marines, Plouzané, France
   IFREMER, Unité Étude des Écosystèmes Profonds, Plouzané, France
   MNHN-UPMC, Paris, France
   TOTAL-CSTJF, Pau, France
C2 IFP ENERGIES NOUVELLES, FRANCE
   IFREMER, FRANCE
   IFREMER, FRANCE
   MNHN, FRANCE
   TOTAL-CSTJF, FRANCE
SI BREST
SE PDG-REM-GM-LCG
   PDG-REM-GM-LGS
   PDG-REM-GM-LAD
   PDG-REM-EEP-LEP
   PDG-REM-GM-CTDI
IN WOS Ifremer UPR
   copubli-france
IF 3.548
TC 8
UR https://archimer.ifremer.fr/doc/00635/74690/74601.pdf
LA English
DT Article
CR PAMELA-MOZ04
BO Pourquoi pas ?
AB Evidences for active fluid seepages have been discovered along the Zambezi continental slope (offshore Southern Mozambique). These seepages are mostly associated with pockmarks which are aligned along a trend parallel to the slope and running closely upstream of the headwall scarp of a wide zone of slope destabilization. Fluid seepages are interpreted as a potential trigger for the slope destabilization. Acoustic anomalies within the water column have been interpreted as related to moderate bubble seepages mostly located outside and only punctually inside the destabilization zone. Exploration with the SCAMPI towed camera system in the widest pockmark (diameter 200 m wide) has shown fluid seepages associated toauthigenic carbonate crusts and bacterial mats. These fluid seepages are also associated to the presence of chemiosynthetic organisms (Vesicomyidae and Thyasiridae bivalves, Siboglinidae tubeworms). The sampled gas in the sediment corresponds mainly to CH4 of microbial origin, generated by hydrogenotrophic methanogenesis from a substrate of organic origin, i.e. a conventional process of genesis of microbial gas in the marine domain. No evidence for thermogenic gas was detected. Another type of pockmarks has been observed within the core of the slope destabilization zone. Most of these pockmarks are inactive in terms of fluid seepage at present time and are associated to carbonate buildups forming chimney geometries. They probably correspond to diagenetic chimneys of former fluid migration pathways that have been exhumed during the mass sliding and the surrounding depression are related to recurrent activity of strong lateral slope currents which have scoured the sediments around. The spatial organization of the slope destabilization features is considered as representative of the temporal evolution of the landslide giving information about the dynamics of slope instability processes. This proposed evolution started by scattered seepages of formation water with dissolved gas. Then free gas seepages appeared notably in the upper part of the slope. This was followed by progressive shallow deformation in the sediments downslope of the main gas seepages. Finally, the whole slope was destabilized forming imbricated landslides exhuming locally former diagenetic chimneys. 
PY 2020
PD OCT
SO Marine Geology
SN 0025-3227
PU Elsevier BV
VL 428
UT 000561216500006
DI 10.1016/j.margeo.2020.106275
ID 74690
ER

EF