FN Archimer Export Format
PT J
TI Pliocene and Pleistocene stratigraphic evolution of the western Niger Delta intraslope basins: A record of glacio-eustatic sea-level and basin tectonic forcings
BT 
AF Chima, Kelvin Ikenna
   Gorini, Christian
   Rabineau, Marina
   Granjeon, Didier
   Do Couto, Damien
   Leroux, Estelle
   Hoggmascall, Nick
AS 1:1,2;2:1;3:3;4:4;5:1;6:5;7:6;
FF 1:;2:;3:;4:;5:;6:PDG-REM-GM-LGS;7:;
C1 Sorbonne Université-ISTeP UMR 7193, F7500 Paris, France
   Alex Ekwueme Federal University, Ndufu-Alike Ikwo, Ebonyi State, Nigeria
   CNRS, UMR 6538, LGO (CNRS/UBO/UBS), Plouzane, France
   IFPEN, Rueil-Malmaison, France
   IFREMER, ZI Pointe du Diable, Plouzane,, France
   Shell International, London, UK
C2 UNIV SORBONNE, FRANCE
   UNIV FED ALEX EKWUEME, NIGERIA
   CNRS, FRANCE
   IFPEN, FRANCE
   IFREMER, FRANCE
   SHELL, UK
SI BREST
SE PDG-REM-GM-LGS
UM LGO
IN WOS Ifremer UPR
   copubli-france
   copubli-europe
   copubli-univ-france
   copubli-int-hors-europe
   copubli-sud
IF 5.114
TC 8
UR https://archimer.ifremer.fr/doc/00655/76737/77887.pdf
LA English
DT Article
DE ;Niger Delta;Intraslope basins;Pliocene;Pleistocene;Seismic stratigraphy;Allocyclic forcing;Eccentricity cycles
AB Although climate proxy (δ18O) across the world ocean basins reveals that orbital forcing significantly controlled the Pliocene and the Pleistocene sediment deposition, and has been demonstrated in seismic and outcrop studies on the continental shelves of many margins, few or no seismic stratigraphic studies have investigated orbital forcing on deep-water sediment records. In this study, we combined detailed seismic stratigraphy and 3D geomorphological analysis of a high-resolution 3D seismic block in a detailed study of the stratigraphic evolution of the western Niger Delta intraslope basins over the last 5.5 Ma. Two mega seismic units named MSU 1 and MSU 2 were identified. The change in sedimentary architecture from (i) mass flows and turbidite sequences to (ii) hemipelagic and turbidite sequences at the MSU 1/MSU 2 transition coincides with a significant (x3) increase in sedimentation rates and a transition from dominant 400 ka eccentricity cycles (from 5.3 Ma-0.8 Ma) to dominant 100 ka eccentricity cycles, at the Middle Pleistocene Transition (MPT) (circa 0.8–0 Ma). The timing of these changes was estimated based on a detailed analysis of seismic facies succession, correlation of seismic markers with high-resolution sea-level and oxygen isotope curves, and estimation of sequence duration. Further changes in the sedimentary record, characterised by turbidite-dominated sequences at the lower part of MSU 1 to mixed mass flows and turbidite sequences at the upper part of MSU 1, were respectively correlated with changes that occurred in the early Pliocene (circa 4.9 Ma) and in the early Pleistocene (circa 2.6 Ma). The depositional sequence on the western Niger Delta intraslope basin is usually characterised by a falling stage erosional surface (FSES) at its base and top (sequence boundary), and by (i) basal MTDs/bypass facies (where preserved), (ii) turbidite feeder channels/aggrading or meandering channel levee complexes and/or MTDs (slides/slumps) and (iii) hemipelagic drapes that successively document the falling stage, lowstand to early transgressive and late transgressive to highstand transits of the shoreline. This seismic stratigraphic study demonstrates for the first-time sequence cyclicity associated with orbital (Milankovitch) forcing in the deep-water Niger Delta over the last 5.5 Ma. The Pliocene and Pleistocene sedimentary records of the western Niger Delta intraslope basins were controlled by interplay between allocyclic forcing linked to glacio-eustatic sea-level oscillations and basin tectonics associated with mobile shale movements, the latter being more prevalent from the early Pliocene to the MPT. If calibrated with high-resolution biostratigraphic data in future studies, this study could serve as a useful analogue for further studies in the Gulf of Guinea, equatorial Atlantic and other margins fed by large deltas. 
PY 2020
PD DEC
SO Global And Planetary Change
SN 0921-8181
PU Elsevier BV
VL 195
UT 000591432000001
DI 10.1016/j.gloplacha.2020.103355
ID 76737
ER

EF