Stalagmite evidence for the precise timing of North Atlantic cold events during the early last glacial

摘要

Evidence of millenniall-scale cold events following the last interglacial are well preserved in North Atlantic marine cores, Greenland ice, and pollen records from Europe. However, their timing was previously undetermined by radiometric dating. We report the first precise radiometric ages for two such events, C23 (105.1 +/- 0.9 ka to 102.6 +/- 0.8 ka) and C24 (112.0 +/- 0.8 ka and 108.8 +/- 1.0 ka), based on stable carbon and oxygen isotope measurements on a stalagmite from Italy (CC28). In addition to providing new information on the duration of these events in southern Europe, the age data provide invaluable tuning points for the Melisey I (C24) and Montaigu (C23) pollen zones identified in western Europe. The former event is of particular significance because it represents the end of the Eemian interglacial forest phase in western Europe. The new age data will also allow fine tuning of the timing and duration of Greenland stadial 24 (equivalent to C23) in the North Greenland Ice Core Project ice core and, via a common gas-age chronology, tuning of the Vostok and EPICA (European Project for Ice Coring in Antarctica) ice cores.