3D de las cuencas de pull-apart en el margen continental atlántico de Tierra del Fuego.

ESTEBAN, F.; TASSONE A.; MENICHETTI, M.; LODOLO E.

Mendoza

Congreso; XXIV Reunión Científica de Geofísica y Geodesia; 2009

AAGG

The region of Tierra del Fuego is characterized for being cut by morphostructural lineaments oriented WNW-ESE to W-E. These structures belong to a set of left-lateral faults that distributed the deformation along the South America-Scotia plate boundary. From south to north, three main fault systems are recognized: Beagle Channel, Carbajal-Lasifashaj and Magallanes-Fagnano. The last constitute the present-day South America-Scotia plate boundary, and extend from the west extreme of the Magallanes strait to the north Scotia ridge in the Atlantic, cutting the Fagnano lake localized in the southern sector of Isla Grande de Tierra del Fuego. Along its trace numerous morphologic and topographic expressions associated to the activity of this boundary plate can be recognized. The more outstanding expression is the developed of pull-apart basins, between them the Lago Fagnano with an E-W extension of 105 Km stands out. Previous publications done by our work group, with 2D seismic offshore Tierra del Fuego propose the existence of Neogene pull-apart basins in correspondence with step overs and realising bends. These were characterized for being controlled by subverticals faults, which occasionally reach the sea-floor, and for showing a clear asymmetric filling, with the greater thickness near the subverticals faults. From the analysis of new multichannel seismic data, and jointly with gravimetric and bathymetric data, a detail description of the tectono-sedimentary evolution of these Neogene basins is presented here, as well as a 3D model, along a 350-km-long area from the shore of Tierra del Fuego to the beginning of the Malvinas Trough, located to the south of the Malvinas islands. Key words: Magallanes-Fagnano Fault System, Pull-apart basins, 3D model, SW Atlantic, Multichannel seismic, Gravimetry.