info:eu-repo/semantics/article
Extensive early deglaciation and paleolake history of the Río Cisnes Ice Lobe, Patagonian Ice Sheet 44°S
Fecha
2019-01Registro en:
García, Juan Luis; Maldonado, Antonio J.; de Porras, Maria Eugenia; Nuevo Delaunay, Amalia; Reyes, Omar; et al.; Extensive early deglaciation and paleolake history of the Río Cisnes Ice Lobe, Patagonian Ice Sheet 44°S; Academic Press Inc Elsevier Science; Quaternary Research; 91; 1; 1-2019; 194-217
0033-5894
CONICET Digital
CONICET
Autor
García, Juan Luis
Maldonado, Antonio J.
de Porras, Maria Eugenia
Nuevo Delaunay, Amalia
Reyes, Omar
Ebensperger, Claudia A
Binnie, Steven A.
Lüthgens Christopher
Mendez, Cesar
Resumen
The timing, structure, and landscape change during the Patagonian Ice Sheet deglaciation remains unresolved. In this article, we provide a geomorphic, stratigraphic, and geochronological deglacial record of Río Cisnes Glacier at 44°S and also from the nearby Río Ñirehuao and Río El Toqui valleys (45°S) in Chilean Patagonia. Our 14C, 10Be, and optically stimulated luminescence data indicate that after the last glacial maximum, Río Cisnes Glacier experienced ∼100 km deglaciation between >19.0 and 12.3 ka, accompanied by the formation of large glacial paleolakes. Deglaciation was interrupted by several ice readvances, and by 16.9±0.3 ka, Río Cisnes Glacier extended only ∼40% of its full glacial extent. The deglaciation of Río Cisnes Glacier and other sensitive Patagonian glaciers occurred at least 1 ka earlier than the ca. 17.8 ka normally assumed for the local termination, coincident with West Antarctic isotope records. This early deglaciation can be linked to an orbital forcing-driven decline of Southern Ocean sea ice associated with a distinct atmospheric warming that is apparent for West Antarctica through Patagonia.