Abstract
ABSTRACTThis paper presents a glacial geomorphological map of landforms produced by the Lago General Carrera–Buenos Aires and Lago Cochrane–Pueyrredón ice lobes of the former Patagonian Ice Sheet. Over 35,000 landforms were digitized into a Geographical Information System from high-resolution (<15 m) satellite imagery, supported by field mapping. The map illustrates a rich suite of ice-marginal glacigenic, subglacial, glaciofluvial and glaciolacustrine landforms, many of which have not been mapped previously (e.g. hummocky terrain, till eskers, eskers). The map reveals two principal landform assemblages in the central Patagonian landscape: (i) an assemblage of nested latero-frontal moraine arcs, outwash plains or corridors, and inset hummocky terrain, till eskers and eskers, which formed when major ice lobes occupied positions on the Argentine steppe; and (ii) a lake-terminating system, dominated by the formation of glaciolacustrine landforms (deltas, shorelines) and localized ice-contact glaciofluvial features (e.g. outwash fans), which prevailed during deglaciation.
Highlights
The Patagonian Ice Sheet (PIS) has episodically expanded across the southern Andes of South America (38–56°S) throughout the Quaternary (Figure 1; Caldenius, 1932; Rabassa, 2008)
This paper presents a glacial geomorphological map of landforms produced by the Lago General Carrera–Buenos Aires and Lago Cochrane–Pueyrredón ice lobes of the former Patagonian Ice Sheet
The map reveals two principal landform assemblages in the central Patagonian landscape: (i) an assemblage of nested latero-frontal moraine arcs, outwash plains or corridors, and inset hummocky terrain, till eskers and eskers, which formed when major ice lobes occupied positions on the Argentine steppe; and (ii) a lake-terminating system, dominated by the formation of glaciolacustrine landforms and localized ice-contact glaciofluvial features, which prevailed during deglaciation
Summary
The Patagonian Ice Sheet (PIS) has episodically expanded across the southern Andes of South America (38–56°S) throughout the Quaternary (Figure 1; Caldenius, 1932; Rabassa, 2008) During such times, substantial ice lobes advanced along major valleys constructing nested terminal moraine sequences and extensive outwash plains on the extra-Andean steppe (Caldenius, 1932). Geomorphological studies, including glacial land-system approaches, have enabled detailed reconstructions of former ice dynamics (Bentley, Sugden, Hulton, & McCulloch, 2005; Darvill, Stokes, Bentley, Evans, & Lovell, 2016; Lovell, Stokes, Bentley, & Benn, 2012) Whilst such methods have been applied in southernmost Patagonia, around central Patagonia and the North Patagonian Icefield (NPI) (∼46–48°S) previous work has focused on constraining the timing of glacial fluctuations, with less attention given to the detailed nature of landform-sediment assemblages (Glasser, Harrison, & Jansson, 2009). The map will provide the foundation for new reconstructions of ice lobe and palaeolake dynamics through the application of glacial inversion methods (Kleman et al, 2006) and land-system analysis (Evans, 2003), and will underpin future chronological investigations
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
