Abstract

Moraines in the Taurus Mountains of south-central Turkey, dated to latest Pleistocene or earliest Holocene, show that glaciers were extraordinarily large, typical of the Last Glacial Maximum (21 ka), and that rates of glacier retreat and temperature rise exceeded those of the past century. Surface exposure ages of 7 moraines in a valley at altitudes between 1100 m and 3100 m above sea level range from 10.2 ± 0.2 ka to 8.6 ± 0.3 ka, computed using our own production rates and spatiotemporal scaling factors. Hitherto unresolved differences in cosmogenic 36Cl production-rate estimates can make these ages significantly older, and therefore the analysis presented here focuses on the rate of change and not on the absolute chronology. During deglaciation, the equilibrium line altitude ascended 1430 m and the air temperature rose by 9 °C. Deglaciation occurred in two phases. During the second, faster phase, which lasted 500 yr, the glacier length decreased at an average rate of 1700 m/100 yr, implying a warming rate of 1.44 °C/100 yr, indicating a rapid climate shift marking the onset of the Holocene in Turkey.

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