Resumen de Opening of Drake Passag: contourites development and paleoceanographic implications

Andrés Maldonado López, Fernando Bohoyo Muñoz, Jesús Galindo Zaldívar, Francisco Javier Hernández Molina, Francisco José Lobo Sánchez, Yasmina M. Martos Martín, Anatoly A. Schreider

• The tectonics and distribution of seismic units of the southwestern Scotia Sea are described based on multichannel seismic profiles and magnetic anomalies. Recently acquired profiles suggest that spreading of the Drake Passage was active prior to 31 Ma. Taking into consideration the timing for breakup and the tectonics of the area, a deep gateway may have developed in Drake Passage close to the Eocene-Oligocene boundary. After the initial breakup the Scotia Sea resulted from several spreading centers that developed deep oceanic basins. Seven seismic units are identified in the Cenozoic deposits. The three youngest units exhibit similar seismic facies and are correlated at regional scale. The deposits show a variety of contourite drifts that resulted from the interplay between the northeastward flows of Weddell Sea Deep Water (WSDW), the Antarctic Circumpolar Current (ACC) and thecomplex bathymetry.