Detailed thin-section petrographic description relative to three diagnostic rock types from the Argentine Continental Margin, Mar del Plata Canyon area

This data set include (1) the detailed petrographic description of the diagnostic rock types used to infer the source areas of the material recovered from the Mar del Plata Canyon area (Western South Atlantic at 38° S) at Sites GeoB13830, GeoB22712, GeoB22717 and L45; and (2) the Acoustic Doppler Current Profiler (ADCP) data obtained from Sites GeoB22716, GeoB22717 and GeoB22732. A variety of gravel- to cobble-sized rocks, recovered from the Mar del Plata Canyon area and interpreted as ice-rafted debris, represents the first evidence that large icebergs have floated in the Falkland (Malvinas) Current from the southern polar high latitudes far northward. Detailed petrographic analyses identified the Antarctic Peninsula, sub-Antarctic islands in the Scotia Sea, and Tierra del Fuego as plausible source areas. In the Mar del Plata Canyon, a combination of local slope instability and strong and persistent contouritic bottom currents, favored local enrichment in dropstones in the form of a loose, coarse sediment drape inside morphological depressions. The bottom current velocity would be locally strong enough to rework this sediment, leaving coarse rafted debris as a lag deposit. Microscopic petrograohic determinations were done on thin sections to identify the mineralogical composition of the rocks. During cruise SONNE SO260-1, the hull mounted Ocean Surveyor Teledyne RDI Acoustic Doppler Current Profiler (ADCP) with a doppler shift of 38 kHz provided real-time current velocity profiles over a range from 38 to 1,200 m water depth. ADCP data from the lowest 10-15 % of the water column have been removed due to possible scattering caused by strong seafloor echo. Doppler shifts were converted into current velocities using real water sound velocities by means of Conductivity-Temperature-Depth (CTD) and Expendable Sound Velocimeter (XSV) profile calibration. Detailed petrographic analysis on specific rock samples from the Mar del Plata Canyon area (SW Atlantic): sites GeoB13830, GeoB22712; GeoB22717 and L45

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Cite this as

Bozzano, Graziella, Cerredo, Maria Elena, Remesal, Marcela, Schwenk, Tilmann, Kasten, Sabine (2020). Dataset: Detailed thin-section petrographic description relative to three diagnostic rock types from the Argentine Continental Margin, Mar del Plata Canyon area. https://doi.org/10.1594/PANGAEA.925566

DOI retrieved: 2020

Additional Info

Field Value
Imported on November 29, 2024
Last update November 29, 2024
License CC-BY-4.0
Source https://doi.org/10.1594/PANGAEA.925566
Author Bozzano, Graziella
Given Name Graziella
Family Name Bozzano
More Authors
Cerredo, Maria Elena
Remesal, Marcela
Schwenk, Tilmann
Kasten, Sabine
Source Creation 2020
Publication Year 2020
Resource Type text/tab-separated-values - filename: Rock_description
Subject Areas
Name: Chemistry

Name: Geophysics

Name: Lithosphere

Related Identifiers
Title: Dropstones in the Mar del Plata Canyon Area (SW Atlantic): Evidence for Provenance, Transport, Distribution, and Oceanographic Implications
Identifier: https://doi.org/10.1029/2020GC009333
Type: DOI
Relation: References
Year: 2020
Source: Geochemistry, Geophysics, Geosystems
Authors: Bozzano Graziella , Cerredo Maria Elena , Remesal Marcela , Steinmann Lena , Hanebuth Till J J , Schwenk Tilmann , Baqués Michele , Hebbeln Dierk , Spoltore Daniela , Silvestri Ornella , Acevedo R D , Spieß Volkhard , Violante R A , Kasten Sabine .