Seismostratigraphy and recent sedimentary evolution of an asymmetric extensional basin at the Western arm of the Magallanes-Fagnano transform system

In 1995, in the frame of the PNRA (Progetto Nazionale di Ricerche in Antartide) the Dipartimento di Scienze Geologiche, Ambientaie e Marine (DISGAM – University of Trieste) performed a marine geological survey within the Pacific entrance of the Magellan Strait with the aim a) to verify the occurrence and effects of the Magellan Fault along the western part of the South America-Scotia plate boundary; and b) to investigate the sedimentary architecture of the sequences of this sector of the Strait, with particular interest to those recording the Pleistocene glacial events. The survey consisted of 290km of intermediate resolution multichannel seismic reflection profiles and three gravity cores. These data were acquired in a marine enlargement of the Magellan Strait north of Isla Desolacion, between Cabo Pilar and Isla Tamar with the R/V OGS Explora (Fig. 1). The analysed data were integrated by a high-resolution seismic line acquired all along the sStrait in 1991 and by other three cores collected during different surveys in 1991 and 1995. The present work summarize the previous report of Bartole et al. (2000) and provide new results obtained by recent analyses of the seismic and sampling data.