GLACIER FLUCTUATIONS IN THE EASTERN ANDES OF COLOMBIA (SOUTH-AMERICA)DURING THE LAST 45,000 RADIOCARBON YEARS

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 depos its and strongly subdued morainic ramparts. Three glacial advances dur ing 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 wit h the period 18.0 to 15.5 ka BP are most distinct. The arcuate, multip le morainic ridge system of up to tens of meters of height can be trac ed 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 glac iations affected only the highest areas of the Eastern Cordillera, whe re morainic complexes associated with at least three glacial events oc cur but remain poorly dated. The glacial record of the Colombian Easte rn Cordillera registers high climatic variability in the tropical Ande s during the Late Quaternary period. Copyright (C) 1996 INQUA/Elsevier Science Ltd.