Middle slope contourite deposits and associated sedimentary facies off NE Argentina
The Argentine continental margin is characterised by a large contourite depositional system driven by southern-sourced water masses flowing at different water depths. Interest in contourite deposits is increasing in geoscience and related fields, though knowledge of the Argentine contourite system i...
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2011
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paper:paper_02760460_v31_n5-6_p495_Bozzano2023-06-08T15:25:53Z Middle slope contourite deposits and associated sedimentary facies off NE Argentina Cerredo, Maria Elena Argentina Climate condition Continental margin Contourite depositional systems Depth range Geosciences Key factors Late Pleistocene-Holocene Patagonia Sediment source areas Sedimentary facies Sedimentary process Water depth Water mass Anoxic sediments Deposits Gravel Magnetic susceptibility Sea level Sedimentology Process control continental margin deposition facies grain size petrography Pleistocene-Holocene boundary sea level slope water depth water mass Argentina The Argentine continental margin is characterised by a large contourite depositional system driven by southern-sourced water masses flowing at different water depths. Interest in contourite deposits is increasing in geoscience and related fields, though knowledge of the Argentine contourite system is still limited. In particular, studies based on core data providing detailed descriptions of sedimentary facies are lacking, as are investigations of principal sediment source areas and of key factors controlling sedimentary processes. This study combines visual core description and downcore grain-size analyses as well as petrographic thin-section and magnetic susceptibility analyses of 14 cores from intermediate water depths of 616-1,208 m to characterise contourite deposits on the north-eastern Argentinean slope. Gravel-rich, sandy-silty and muddy contourites as well as hemipelagic facies were identified. The deposition of these contourites was presumably controlled by sea level, the depth range of the Antarctic water mass, climate conditions and windborne terrigenous supply. It is proposed that, during glacial lowstands, muddy contourites were deposited at depths <900 m, whereas sandy-silty sequences dominated at deeper depths. During the late Pleistocene-Holocene transition, sandy-silty contourites covered the entire middle slope. Hemipelagic facies draped limited sectors of the middle slope when the sea level reached the present-day position and gravel-rich contourites became restricted to contouritic channels and moats. Northern Patagonia and the southern Pampa are the most plausible sources for sediments deposited via along-slope processes, whereas the Tandilia Range is the best candidate for sediments deposited via down-slope processes. © 2011 Springer-Verlag. Fil:Cerredo, M.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2011 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02760460_v31_n5-6_p495_Bozzano http://hdl.handle.net/20.500.12110/paper_02760460_v31_n5-6_p495_Bozzano |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Argentina Climate condition Continental margin Contourite depositional systems Depth range Geosciences Key factors Late Pleistocene-Holocene Patagonia Sediment source areas Sedimentary facies Sedimentary process Water depth Water mass Anoxic sediments Deposits Gravel Magnetic susceptibility Sea level Sedimentology Process control continental margin deposition facies grain size petrography Pleistocene-Holocene boundary sea level slope water depth water mass Argentina |
| spellingShingle |
Argentina Climate condition Continental margin Contourite depositional systems Depth range Geosciences Key factors Late Pleistocene-Holocene Patagonia Sediment source areas Sedimentary facies Sedimentary process Water depth Water mass Anoxic sediments Deposits Gravel Magnetic susceptibility Sea level Sedimentology Process control continental margin deposition facies grain size petrography Pleistocene-Holocene boundary sea level slope water depth water mass Argentina Cerredo, Maria Elena Middle slope contourite deposits and associated sedimentary facies off NE Argentina |
| topic_facet |
Argentina Climate condition Continental margin Contourite depositional systems Depth range Geosciences Key factors Late Pleistocene-Holocene Patagonia Sediment source areas Sedimentary facies Sedimentary process Water depth Water mass Anoxic sediments Deposits Gravel Magnetic susceptibility Sea level Sedimentology Process control continental margin deposition facies grain size petrography Pleistocene-Holocene boundary sea level slope water depth water mass Argentina |
| description |
The Argentine continental margin is characterised by a large contourite depositional system driven by southern-sourced water masses flowing at different water depths. Interest in contourite deposits is increasing in geoscience and related fields, though knowledge of the Argentine contourite system is still limited. In particular, studies based on core data providing detailed descriptions of sedimentary facies are lacking, as are investigations of principal sediment source areas and of key factors controlling sedimentary processes. This study combines visual core description and downcore grain-size analyses as well as petrographic thin-section and magnetic susceptibility analyses of 14 cores from intermediate water depths of 616-1,208 m to characterise contourite deposits on the north-eastern Argentinean slope. Gravel-rich, sandy-silty and muddy contourites as well as hemipelagic facies were identified. The deposition of these contourites was presumably controlled by sea level, the depth range of the Antarctic water mass, climate conditions and windborne terrigenous supply. It is proposed that, during glacial lowstands, muddy contourites were deposited at depths <900 m, whereas sandy-silty sequences dominated at deeper depths. During the late Pleistocene-Holocene transition, sandy-silty contourites covered the entire middle slope. Hemipelagic facies draped limited sectors of the middle slope when the sea level reached the present-day position and gravel-rich contourites became restricted to contouritic channels and moats. Northern Patagonia and the southern Pampa are the most plausible sources for sediments deposited via along-slope processes, whereas the Tandilia Range is the best candidate for sediments deposited via down-slope processes. © 2011 Springer-Verlag. |
| author |
Cerredo, Maria Elena |
| author_facet |
Cerredo, Maria Elena |
| author_sort |
Cerredo, Maria Elena |
| title |
Middle slope contourite deposits and associated sedimentary facies off NE Argentina |
| title_short |
Middle slope contourite deposits and associated sedimentary facies off NE Argentina |
| title_full |
Middle slope contourite deposits and associated sedimentary facies off NE Argentina |
| title_fullStr |
Middle slope contourite deposits and associated sedimentary facies off NE Argentina |
| title_full_unstemmed |
Middle slope contourite deposits and associated sedimentary facies off NE Argentina |
| title_sort |
middle slope contourite deposits and associated sedimentary facies off ne argentina |
| publishDate |
2011 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02760460_v31_n5-6_p495_Bozzano http://hdl.handle.net/20.500.12110/paper_02760460_v31_n5-6_p495_Bozzano |
| work_keys_str_mv |
AT cerredomariaelena middleslopecontouritedepositsandassociatedsedimentaryfaciesoffneargentina |
| _version_ |
1768542313636691968 |