GEOLOGICAL AND GEOPHYSICAL INVESTIGATIONS OF THE MAIN MORPHOSEDIMENTARY FEATURES OF THE PATAGONIAN CONTINENTAL MARGIN: NEW DATA ACQUIRED ON BOARD OF THE AUSTRAL R/V

PRINCIPI, S.; TASSONE, A.A.; ISOLA, J.I.; ORMAZABAL, J.P.; PALMA, F.I.; BOZZANO, G.; SPOLTORE, D.

Atenas

Congreso; Regional Conference on Geomorphology (IAG); 2019

The Patagonian Continental Margin (PCM) corresponds to the portion of the Argentinecontinental margin located southwards the outlet of the Río Colorado and its continuationalong the Colorado Fracture Zone; it includes the northern Scotia Ridge, and the shelf andcontinental slope adjacent to continental Patagonia, Tierra del Fuego, and Malvinas Islands.Just a small part of this huge territory has been surveyed with high resolution multi-beambathymetry, and most of its morphology remains unknown. In the years 2017 and 2018 threecruises were performed on board of the R/V Austral - framed on collaboration betweenPAMPA AZUL, CONICET, Y-TEC and YPF - where three key areas of the PCM weresurveyed: Tierra del Fuego, Malvinas shelf, and the slope adjacent to continental Patagonia.During these cruises, hydro-acoustic data was acquired with the hull-mounded systems:multi-beam echo-sounders Kongsberg EM 122 and EM Kongsberg 2040, and parametric subbottom profiler PARASOUND P70. Along with the hydro-acoustic data, 33 sediment coreswere obtained in water depths spanning from 130 m to 3480 m. This new set of data revealedthe geomorphology of the surveyed areas with unprecedented detail, and a plethora ofseafloor features -such as sub-marine canyons, ploughmarks and pockmarks- were imagedfor the first time. This contribution aims to introduce the main discoveries of these cruises aswell as to discuss the influence that the different processes had in shaping each of the areas.The morphometrical study of the bathymetric data, along with the shallow seismic structureand the sedimentological analysis of the cores provides evidence of a dynamic interplaybetween gravitational and contouritic processes.