Morphosedimentary analysis of the Sloggett submarine canyon and its regional implications. NW Scotia Sea.

PALMA F.I.; ESTEBAN F. D.; ISOLA J. I.; PRINCIPI, S

Atenas

Conferencia; Regional Conference on Geomorphology; 2019

Thesouthern Argentine Continental Margin (ACM) is incised by deep andlarge canyons that belong to the canyon?s system of Tierra delFuego. The Sloggett Canyon, located in northwestern Scotia Sea, isthe longest with a total length of 142 km along the thalweg, cuttingthe continental shelf, slope and abyssal plain. In this work wepresent a morphosedimentary and structural analysis of the canyonrevealed from recently data obtained on board the R/V Austral in theYTEC-GTGM0 cruise in September 2017. It consists in the firstcomplete very-high resolution imaging (up to 20 meters) of the canyonfrom its upper part down to its distalmost reach. Swath bathymetrywith the echosounder EM-122 and sub-bottom profiler with ParasoundP70 were used for distinguish morphologies made by processes oferosion, transport and deposition. The head is affected bytributaries channels that range in size, direction and depth and actas a conduit for gravity flows and turbidity currents. They have awide expression in the east flank regarding the western flank wherepredominate wall slumping, gullies and scar. The canyon was studiedconsidering three parts of the thalweg, where the direction changesabruptly two times from NW-SE to SW-NE in an angle of approximately90 degrees. This was associated with the NW-SE lineaments of the WestScotia Ridge, where could be acted as a path for the canyon and theBeagle Channel Fault System that has a W-E direction affecting theslope. Additionally, along-processes related to the strong oceaniccurrents form contourites drifts and erode the margin to formcontourites terraces along canyon depth. The canyon has a connectionwith the Sloggett Bay (10 km north) and can be considered as acontinuation of the Sloggett Continental Tectonic Lineament. p { margin-bottom: 0.25cm; direction: ltr; line-height: 115%; text-align: left; }a:link { color: rgb(0, 0, 255); }