FN Archimer Export Format
PT J
TI Deep-water dunes on drowned isolated carbonate terraces (Mozambique Channel, south-west Indian Ocean)
BT 
AF MIRAMONTES, Elda
   Jorry, Stephan
   Jouet, Gwenael
   Counts, John
   Courgeon, Simon
   Roy, Philippe
   Guerin, Charline
   Hernández-Molina, F. Javier
AS 1:1;2:2;3:2;4:3;5:4;6:1;7:2;8:5;
FF 1:;2:PDG-REM-GM-LGS;3:PDG-REM-GM-LGS;4:;5:;6:;7:PDG-REM-GM-CTDI;8:;
C1 UMR6538; CNRS-UBO; IUEM; Laboratoire Géosciences Océan; 29280 Plouzané, France
   IFREMER; Géosciences Marines; 29280 Plouzané ,France
   School of Earth Sciences; University College Dublin; Belfield, Dublin 4 ,Ireland
   University of Geneva; Department of Earth Sciences; 1205 Geneva, Switzerland
   Department of Earth Sciences; Royal Holloway; University of London; Egham Surrey TW20 0EX, United Kingdom
C2 CNRS, FRANCE
   IFREMER, FRANCE
   UNIV COLL DUBLIN, IRELAND
   UNIV GENEVA, SWITZERLAND
   UNIV LONDON, UK
SI BREST
SE PDG-REM-GM-LGS
   PDG-REM-GM-CTDI
UM LGO
IN WOS Ifremer UPR
   copubli-france
   copubli-europe
   copubli-int-hors-europe
IF 3.405
TC 13
UR https://archimer.ifremer.fr/doc/00472/58418/60989.pdf
LA English
DT Article
CR GEBCO 2005 LEG 1
   GEBCO 2005 LEG 2
   GEBCO 2006 LEG 1
   GEBCO 2006 LEG 2
   PAMELA-MOZ01
   PAMELA-MOZ02
   PAMELA-MOZ03
   PAMELA-MOZ04
   PAMELA-MOZ04-HA
   PAMELA-MOZ05
   PAMELA-MOZ08
   PAMELA-PAPRICA
   PTOLEMEE_PAMELA
BO Beautemps-Beaupré
   L'Atalante
   Pourquoi pas ?
   Haliotis
   Antea
DE ;Bedform;bottom currents;contourite;deep-marine environment;eddy;geostrophic current;oceanic circulation
AB Subaqueous sand dunes are common bedforms on continental shelves dominated by tidal and geostrophic currents. However, much less is known about sand dunes in deep‐marine settings that are affected by strong bottom currents. In this study, dune fields were identified on drowned isolated carbonate platforms in the Mozambique Channel (south‐west Indian Ocean). The acquired data include multibeam bathymetry, multi‐channel high‐resolution seismic reflection data, sea floor imagery, a sediment sample and current measurements from a moored current meter and hull‐mounted acoustic Doppler current profiler. The dunes are located at water depths ranging from 200 to 600 m on the slope terraces of a modern atoll (Bassas da India Atoll) and within small depressions formed during tectonic deformation of drowned carbonate platforms (Sakalaves Seamount and Jaguar Bank). Dunes are composed of bioclastic medium size sand, and are large to very large, with wavelengths of 40 to 350 m and heights of 0.9 to 9.0 m. Dune migration seems to be unidirectional in each dune field, suggesting a continuous import and export of bioclastic sand, with little sand being recycled. Oceanic currents are very intense in the Mozambique Channel and may be able to erode submerged carbonates, generating carbonate sand at great depths. A mooring located at 463 m water depth on the Hall Bank (30 km west of the Jaguar Bank) showed vigorous bottom currents, with mean speeds of 14 cm sec−1 and maximum speeds of 57 cm sec−1, compatible with sand dune formation. The intensity of currents is highly variable and is related to tidal processes (high‐frequency variability) and to anticyclonic eddies near the seamounts (low‐frequency variability). This study contributes to a better understanding of the formation of dunes in deep‐marine settings and provides valuable information about carbonate preservation after drowning and the impact of bottom currents on sediment distribution and sea floor morphology. 
PY 2019
PD JUL
SO Sedimentology
SN 0037-0746
PU Wiley
VL 66
IS 4
UT 000472679400003
BP 1222
EP 1242
DI 10.1111/sed.12572
ID 58418
ER

EF