FN Archimer Export Format
PT J
TI Polygonal faults-furrows system related to early stages of compaction - upper Miocene to recent sediments of the Lower Congo Basin
BT 
AF GAY, Aurelien
   LOPEZ, M
   COCHONAT, Pierre
   SERMONDADAZ, G
AS 1:;2:;3:;4:;
FF 1:PDG-DRO-GM-SEDIMENTS;2:;3:PDG-DRO;4:;
C1 Univ Lille 1, Lab Sedimentol & Geodynam, F-59655 Villeneuve Dascq, France.
   Univ Montpellier 2, Lab Geophys Tecton & Sedimentol, F-34095 Montpellier, France.
   IFREMER, Dept Geosci Marines, Lab Environm Sedimentaires, F-29280 Plouzane, France.
   Total Fina Elf, F-64018 Pau, France.
C2 UNIV LILLE 1, FRANCE
   UNIV MONTPELLIER 2, FRANCE
   IFREMER, FRANCE
   TOTAL, FRANCE
SI BREST
   SIEGE
SE PDG-DRO-GM-SEDIMENTS
   PDG-DRO
IN WOS Ifremer jusqu'en 2018
   copubli-univ-france
IF 1.582
TC 99
UR https://archimer.ifremer.fr/doc/2004/publication-1115.pdf
LA English
DT Article
DE ;Water sediment interface;Seafloor;Sedimentary basin;Geometrical model;Furrow;Fault system
AB A new polygonal fault system has been identified in the Lower Congo Basin. This highly faulted interval (HFI), 700+/-50 m thick, is characterized by small extensional faults displaying a polygonal pattern in plan view. This kind of fracturing is attributed to volumetric contraction of sediments during early stages of compaction at shallow burial depth. 3-D seismic data permitted the visualization of the progressive deformation of furrows during burial, leading to real fractures, visible on seismic sections at about 78 m below seafloor. We propose a new geometrical model for volumetrical contraction of mud-dominated sediments. Compaction starts at the water-sediment interface by horizontal contraction, creating furrows perpendicular to the present day slope. During burial, continued shrinkage evolves to radial contraction, generating hexagonal cells of dewatering at 21 m below seafloor. With increasing contraction, several faults generations are progressively initiated from 78 to 700 m burial depth. Numerous faults of the HFI act as highly permeable pathways for deeper fluids. We point out that pockmarks, which represent the imprint of gas, oil or pore water escape on the seafloor, are consistently located at the triple-junction of three neighbouring hexagonal cells. This is highly relevant for predictive models of the occurrence of seepage structures on the seafloor and for the sealing capacity of sedimentary cover over deeper petroleum reservoirs.
PY 2004
PD MAR
SO Basin Research
SN 0950-091X
PU Blackwell science
VL 16
IS 1
UT 000189294100006
BP 101
EP 116
DI 10.1111/j.1365-2117.2003.00224.x
ID 1115
ER

EF