Lucchi, Renata G. and Rebesco, Michele (2007): Glacial contourites on the Antarctic Peninsula margin; insight for palaeoenvironmental and palaeoclimatic conditions

Leg/Site/Hole:
ODP 178
ODP 178 1096
ODP 178 1097
ODP 178 1101
Identifier:
2008-039595
georefid

Creator:
Lucchi, Renata G.
Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Trieste, Italy
author

Rebesco, Michele
Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Italy
author

Identification:
Glacial contourites on the Antarctic Peninsula margin; insight for palaeoenvironmental and palaeoclimatic conditions
2007
In: Viana, Adriano R. (editor), Rebesco, Michele (editor), Economic and palaeoceanographic significance of contourite deposits
Geological Society of London, London, United Kingdom
276
111-127
Deep-sea finely laminated and barren glacial sediments occur in the sediment drift field offshore the Pacific margin of the Antarctic Peninsula where a weak contour current flows at present to the SW. Atypical sedimentary facies were related to the coexistence and interaction of different sedimentary processes. Three "end-members" of radiograph facies were defined to represent the sedimentary sequences controlled by a dominant process, as follows. (1) Direct influence of turbidity currents on sedimentation is observed in the area surrounding the Alexander Channel system with silty layers interbedded with laminated mud free of ice-rafted debris (IRD). (2) Distal meltwater turbid flows dominate the more proximal area of the top plateau with structureless and coarser-grained sediments containing IRD. (3) Along the crest of the drift, persistent weak bottom currents control the deposition of fine-grained sediments conveyed into the system through other processes. These laminated sediments contain IRD and are, atypically, not bioturbated, because of unusual, climatically related, environmental conditions of suppressed primary productivity and oxygen-reduced deep waters. These glacial contourites were observed on most of the Antarctic margin with the exception of the areas in which polynyas were maintained during the glacial stages. Glacial contourites can be used as a proxy to define temporal and spatial extension of the Antarctic sea-ice.
English
Serial
Coverage:Geographic coordinates:
North:-64.0000
West:-80.0000East: -70.0000
South:-70.0000

Quaternary geology; Antarctic Peninsula; Antarctica; Cenozoic; clastic sediments; continental margin; contour currents; contourite; currents; deep-sea sedimentation; drift; Drift 7; geophysical methods; geophysical profiles; geophysical surveys; glacial environment; ice; laminations; Leg 178; lithofacies; marine sedimentation; mud; ocean currents; Ocean Drilling Program; ODP Site 1096; ODP Site 1097; ODP Site 1101; paleoclimatology; paleoenvironment; planar bedding structures; polynyas; progradation; Quaternary; sea ice; sedimentary structures; sedimentation; sediments; seismic methods; seismic profiles; silt; Southern Ocean; surveys; thickness; turbidite; turbidity currents;

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