OCEAN-ATMOSPHERIC FORCING OF LATE GLACIAL AND HOLOCENE GLACIER FLUCTUATIONS IN THE EASTERN AND WESTERN CORDILLERA OF THE TROPICAL PERUVIAN ANDES

Terrestrial cosmogenic nuclide (TCN) ages on moraine boulders combined with ¹⁴C-dated clastic sediment records from alpine lakes document glacial variability in the Eastern and Western Cordillera of Peru during the last ca. 16 ka. Late Glacial ice extents culminated at the start of the Antarctic Cold Reversal (ACR) and began retracting prior to the Younger Dryas (YD). Multiple moraine crests dating to the early Holocene mark brief readvances or stillstands that punctuated overall retreat of valley glacier termini during this interval. Glaciers were less extensive during the middle Holocene before experience a complex pattern of glacial variability during the latest Holocene. These records suggest that tropical Atlantic and Pacific ocean-atmospheric processes exerted temporally variable forcing of Late Glacial and Holocene glacial changes in the Peruvian Andes.