Interaction of a deep-sea current with a blind submarine canyon (Mar del Plata Canyon, Argentina)

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Autori principali: Warratz, Grit, Schwenk, Tilmann, Voigt, Ines, Bozzano, Graziella, Henrich, Rüdiger, Violante, Roberto, Lantzsch, Hendrik
Natura: Dataset Open Access
Lingua:en
Pubblicazione: PANGAEA 2019
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author Warratz, Grit
Schwenk, Tilmann
Voigt, Ines
Bozzano, Graziella
Henrich, Rüdiger
Violante, Roberto
Lantzsch, Hendrik
author_facet Warratz, Grit
Schwenk, Tilmann
Voigt, Ines
Bozzano, Graziella
Henrich, Rüdiger
Violante, Roberto
Lantzsch, Hendrik
collection Datos científicos de ciencias marinas y ambientales
contents The Mar del Plata (MdP) Canyon at the Argentine continental margin is incorporated into a major contourite depositional system, built by the incursion of southern-sourced water masses affecting the seafloor at different waters depths. The new sedimentological, morphological and hydro acoustic data provide novel insights into contour and turbidity current interactions in mid-slope (blind) canyons, which do not have a connection to the shelf or an onshore river system. Such canyons are capable to record climate-related ocean stratification changes, current variability, and slope stability. Three sediment cores were obtained along the MdP Canyon thalweg covering the last 20,000 years and compiled with two cores from the adjacent Ewing Terrace. Turbidity-current activity within the MdP Canyon was limited to the time interval from Last Glacial Maximum (LGM) to the late deglacial. During the LGM and early deglacial, turbidites reached both the proximal sector and the distal northern flank of the canyon. During the late deglacial only the proximal sector was characterized by turbidite deposition. Similarities in mineralogy and grain-size data indicate that the material transported by the turbidity currents originated from the mid-slope Ewing Terrace. Glacial turbidity-current activity was most probably favored by increased sediment supply along the Ewing Terrace from a shallowed and/or enhanced glacial Antarctic Intermediate Water (AAIW) nepheloid layer. These sediments were trapped by the MdP Canyon, in particular at the head area. During the late deglacial, a displacement or limited AAIW nepheloid layer resulted in less sediment transfer along the Ewing Terrace and immediate accumulation in the MdP Canyon head restricting turbidite deposition to the proximal sector of the canyon. In general, contourite-turbidite interactions provide valuable information on variations in thermohaline circulation such as AAIW distribution and current strength.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_904259
institution PANGAEA
language en
publishDate 2019
publisher PANGAEA
record_format pangaea
spellingShingle Interaction of a deep-sea current with a blind submarine canyon (Mar del Plata Canyon, Argentina)
Warratz, Grit
Schwenk, Tilmann
Voigt, Ines
Bozzano, Graziella
Henrich, Rüdiger
Violante, Roberto
Lantzsch, Hendrik
Argentina; Center for Marine Environmental Sciences; contourite; Mar del Plata Canyon; MARUM; turbidite
The Mar del Plata (MdP) Canyon at the Argentine continental margin is incorporated into a major contourite depositional system, built by the incursion of southern-sourced water masses affecting the seafloor at different waters depths. The new sedimentological, morphological and hydro acoustic data provide novel insights into contour and turbidity current interactions in mid-slope (blind) canyons, which do not have a connection to the shelf or an onshore river system. Such canyons are capable to record climate-related ocean stratification changes, current variability, and slope stability. Three sediment cores were obtained along the MdP Canyon thalweg covering the last 20,000 years and compiled with two cores from the adjacent Ewing Terrace. Turbidity-current activity within the MdP Canyon was limited to the time interval from Last Glacial Maximum (LGM) to the late deglacial. During the LGM and early deglacial, turbidites reached both the proximal sector and the distal northern flank of the canyon. During the late deglacial only the proximal sector was characterized by turbidite deposition. Similarities in mineralogy and grain-size data indicate that the material transported by the turbidity currents originated from the mid-slope Ewing Terrace. Glacial turbidity-current activity was most probably favored by increased sediment supply along the Ewing Terrace from a shallowed and/or enhanced glacial Antarctic Intermediate Water (AAIW) nepheloid layer. These sediments were trapped by the MdP Canyon, in particular at the head area. During the late deglacial, a displacement or limited AAIW nepheloid layer resulted in less sediment transfer along the Ewing Terrace and immediate accumulation in the MdP Canyon head restricting turbidite deposition to the proximal sector of the canyon. In general, contourite-turbidite interactions provide valuable information on variations in thermohaline circulation such as AAIW distribution and current strength.
title Interaction of a deep-sea current with a blind submarine canyon (Mar del Plata Canyon, Argentina)
topic Argentina; Center for Marine Environmental Sciences; contourite; Mar del Plata Canyon; MARUM; turbidite
url https://doi.org/10.1594/PANGAEA.904259