Glacier fluctuations in the Eastern Andes of Colombia (south America) during the last 45,000 radiocarbon years

Abstract

Abstract Major glacial advances in the Eastern Cordillera of Colombia preceded the global ice volume maximum at ca. 20 ka BP. Two glacial events are recognized for Isotope Stage 3, dated between probably 43 and 38 ka BP and between 36 and 31 ka BP. The events are recorded in glacial deposits and strongly subdued morainic ramparts. Three glacial advances during Isotope Stage 2 are dated between 23.5 and 19.5 ka BP, 18.0 and 15.5 ka BP and 13.5 and 12.5 ka BP. The glacial landforms associated with the period 18.0 to 15.5 ka BP are most distinct. The arcuate, multiple morainic ridge system of up to tens of meters of height can be traced throughout the region. The moraines that formed during the earlier Isotope Stage 2 advance are more subdued. The youngest Isotope Stage 2 morainic complex consists of low winding ridges. Isotope Stage 1 glaciations affected only the highest areas of the Eastern Cordillera, where morainic complexes associated with at least three glacial events occur but remain poorly dated. The glacial record of the Colombian Eastern Cordillera registers high climatic variability in the tropical Andes during the Late Quaternary period.