Post-rift sedimentary evolution of the Antarctic Peninsula margin (Central Bransfield Basin)

• Main Authors: García, Marga, Ercilla, Gemma, Anderson, John B., Alonso, Belén
• Format: Conference Object
• Language: English
• Published: Sociedad Geológica de España 2008
• Subjects: Antarctica; Bransfield Basin; Glacial processes; Glaciomarine processes; Estratigraphy; Antártida; Cuenca de Bransfield; Procesos glaciales; Procesos glaciomarinos; Estratigrafía; Alta; Antarctic; Antarctic Peninsula; Hielo; Las Palmas; The Antarctic; Antarc*; Antártica; Ice Sheet
• Online Access: http://hdl.handle.net/10261/86604

VII Congreso Geológico de España, 14-18 Julio 2008, Las Palmas de Gran Canaria.-- 4 pages, 3 figures [EN] The Antarctic Peninsula margin of the Central Bransfield Basin has been studied on the base of high-resolution single-channel reflection seismic profiles and swath bathymetric data. Two seismic sequences (S2 and S1, from older to younger) compose the post-rift stratigraphic section on the slope platforms, lower slope and basin. Sequences and units within them are related with cycles of glacial advance and retreat of the Antarctic Peninsula Ice Sheet (APIS) after the basin opening, about 3.3 Ma. This study reveals that the APIS grounded on the outer slope platforms on several occasions in the past. Glacial and glaciomarine related features developed during the advance and glacial maximum stages, while glaciomarine and marine features predominated during the ice sheet retreat and interglacial stages. S2 has a predominantly progradational stacking pattern, while S1 displays a progradational/aggradational pattern. This change in the stratigraphic architecture is correlated with global climatic changes that controlled the frequency of ice sheet grounding events. Also, changes in the distribution and sedimentary structure of units reveal the influence of topography and climate on glacial and glaciomarine processes [ES] El estudio sobre el margen de la Península Antártica en la Cuenca Central de Bransfield se basa en perfiles de sísmica de reflexión monocanal de alta resolución (airgun) y batimetría multihaz. El relleno sísmico post-rift está formado por dos secuencias sísmicas (S2 y S1, de más antigua a más reciente) en las plataformas de talud, talud inferior y cuenca. Estas secuencias y las unidades que las componen se relacionan con ciclos de avance y retroceso de la capa de hielo de la Península Antártica desde la apertura de la cuenca (3.3. Ma). La capa de hielo estuvo anclada en las zonas distales de las plataformas de talud en numerosas ocasiones, desarrollando depósitos glaciales y glaciomarinos ...