FN Archimer Export Format
PT J
TI Cenozoic evolution of mobile shales and fluid migration to seafloor: 3D seismic evidence from the offshore western Niger Delta
BT 
AF Chima, Kelvin Ikenna
   Leroux, Estelle
   Do Couto, Damien
   Praeg, Daniel
   Igbokwe, Onyedika Anthony
   Mora-Glukstad, Miguel
   Hoggmascall, Nick
   Rabineau, Marina
   Granjeon, Didier
   Gorini, Christian
AS 1:1,2,3;2:1;3:2;4:2,4;5:3,5;6:6;7:7;8:8;9:9;10:2;
FF 1:PDG-REM-GEOOCEAN-GIPS;2:PDG-REM-GEOOCEAN-GIPS;3:;4:;5:;6:;7:;8:;9:;10:;
C1 Institut Français de Recherche et Exploitation de la Mer (IFREMER), Z.I. Pointe du Diable, 29280 Plouzané, France
   Sorbonne Université-Institut des Sciences de la Terre de Paris (ISTeP), UMR 7193, France
   Alex-Ekwueme Federal University, Ndufu-Alike Ikwo, Ebonyi State, Nigeria
   Geoazur (UMR7329 CNRS), 250 Rue Albert Einstein, Valbonne, France
   Ruhr-University Bochum, Institute of Geology, Mineralogy and Geophysics, Universitatsstraße 150, 44801 Bochum, Germany
   Ras Al Hamra Petroleum Development Oman (PDO), Oman
   Brunei Shell Petroleum Sendirian Berhad, Jalan Utara, Panaga, Seria KB2933, Brunei Darussalam
   CNRS, Univ Brest, Univ. Bretagne-Sud, Laboratoire Géosciences Océan (LGO), UMR6538, IUEM, rue Dumont d'Urville, F-29280 Plouzané, France
   Institut Français du Pétrole Energies Nouvelles (IFPEN), Rueil Malmaison, France
C2 IFREMER, FRANCE
   UNIV SORBONNE, FRANCE
   UNIV FED ALEX EKWUEME, NIGERIA
   CNRS, FRANCE
   UNIV BOCHUM, GERMANY
   PDO, OMAN
   SHELL, BRUNEI
   CNRS, FRANCE
   IFPEN, FRANCE
SI BREST
SE PDG-REM-GEOOCEAN-GIPS
UM GEO-OCEAN
IN WOS Ifremer UMR
   WOS Cotutelle UMR
   copubli-france
   copubli-europe
   copubli-univ-france
   copubli-int-hors-europe
   copubli-sud
IF 2.9
TC 0
UR https://archimer.ifremer.fr/doc/00791/90282/95862.pdf
LA English
DT Article
DE ;Niger Delta;3D seismic;Shale tectonics;Mud volcano;Syn-depositional deformation;Pockmarks;Fluid migration
AB The offshore Niger Delta provides a spectacular example of gravity collapse tectonics, but the timing of shale mobilisation remains poorly understood. Here we present new information from the western Niger Delta, based on a detailed interpretation of a 3D seismic volume, calibrated with biostratigraphic data from exploration wells. The study area is underlain by mobile shales containing thrust-fold anticlines, overlain by >5 km thick Late Eocene to present succession of folded and faulted sediments with fluid migration features. Sedimentation rates estimated at one deep well increased during two phases, more than doubling during the Late Eocene to Serravallian (39.5–12.5 Ma), and by up to ten times during the Tortonian (9.5 Ma) to present. Thinning and onlapping geometries within the lowermost, Late Eocene-Burdigalian (39.5–18.5 Ma) interval are interpreted to record syn-depositional deformation. This indicates that shale tectonics in the offshore western Niger Delta initiated early in the evolution of the region, supporting previous interpretations that the active compressional zone of the Niger Delta was in the present continental slope before prograding to the outer-fold-thrust belt in the Pliocene. Stratal thinning above the crests of thrust-fold anticlines in the northeast and southwest of the study area suggests that shale tectonics persisted throughout the Neogene and Quaternary. A chaotic column that rises to seafloor from the crest of thrust-fold anticline, interfingering with the stratified succession is interpreted as a mud volcano edifice that has been active since at least the Burdigalian. This supports early shale mobilisation in response to generation of overpressure and also the fact that mud volcano system once formed, may act as conduits for pressure release throughout the history of a gravity-driven collapse system. The spatial association of seafloor mud volcanoes and pockmarks with deeper thrust-fold anticlines and normal faults suggests fluid migration from depth. In contrast, pockmarks overlying mass-transport deposits and submarine channels suggest fluid-flow from dewatering of more recent sediments. Our findings provide new insights into the Cenozoic tectono-stratigraphic evolution of the offshore western Niger Delta and the relation of shale mobility to fluid migration and escape during continental margin collapse. 
PY 2022
PD SEP
SO Marine Geology
SN 0025-3227
PU Elsevier BV
VL 451
UT 000909883400002
DI 10.1016/j.margeo.2022.106890
ID 90282
ER

EF