Bathymetric survey of Lago Fagnano. Tierra del Fuego Island

TASSONE, A; LODOLO E.; HORMAECHEA, J. L.; MENICHETTI, M.; FERRER, C.; CONNON, G.

Montevideo

Congreso; Congreso Latinoamericano de Geología; 2001

Asociación Geológica de Uruguay. Asociación Latinoamericana de Geología

A bathymetric survey of the Lago Fagnano, located in the central part of the Tierra del Fuego Island, has for the first time been perfomied, in order to identify the morphoslructural expression of the Magallanes-Fagnano Fault System, and to delinéate the main submerged features of the South America-Scotia píate boundary. The most important featurc comprises a prominent scarp which parallels the northern shorc of the Lago Fagnano, and aligns with a weak E-W-trending depression located onshorc to the east, which has bcen idcntified from rcniote-sensing and field data. The N-S profile shows an asymmetric shape with llic slecpest slopc in (he northern margin. The tuaximuní depth of the Lago Fagnano is 201 m. The analysis of the outcropping rocks along the northern flank of the Lago Fagnano, regionally correlated with remote-sensing data, has shown the surfacc expression of this scarp. Ucrc, Upper Cretaceous mudstones have been involved in a thrust shear zone, which has been overprinted by a slrong strike-slip E-W lefl lateral shear. The Quaternaiy sediments, mainly located along the southern and southeastern shorelines, are also affected by the E-W strike-slip defonnation.