Late Pleistocene to Holocene glacial, periglacial, and paraglacial geomorphology of the upper Río Limarí basin (30–31° S) in the Andes of central Chile

Abstract

ABSTRACT We present a field-based reconstruction of the geomorphology in the Subtropical Andean mountains of the Limarí basin, semiarid central Chile (30–31° S). Fieldwork campaigns and remote-sensing analysis served for detailed geomorphological mapping at four formerly glaciated valleys in the heads of the Combarbalá and Río Hurtado sub-basins. We identify a mosaic of glacial, periglacial, and paraglacial landforms. Glacial landforms include a massive dead-ice moraine complex, with thermokarst and debris-filled fractures suggesting former ice-cored moraine degradation. This landform is superimposed by transversal and arcuate ridges suggesting active-ice processes. Periglacial landforms such as rock glaciers, gelifluction, and protalus lobes occur in cirques and U-shaped valleys, but also on moraine deposits. Paraglacial processes are indicated by talus accumulation in those formerly glaciated slopes. The geomorphological imprint is evidence for the interaction and succession between glacial, periglacial, and paraglacial dynamics from the Late Pleistocene to the present.