title: 10Be evidence for the Matuyama-Brunhes geomagnetic reversal in the EPICA Dome C ice core.
abstract: An ice core drilled at Dome C, Antarctica, is the oldest ice core so far retrieved. On the basis of ice flow modelling and a comparison between the deuterium signal in the ice with climate records from marine sediment cores, the ice at a depth of 3,190 m in the Dome C core is believed to have been deposited around 800,000 years ago, offering a rare opportunity to study climatic and environmental conditions over this time period. However, an independent determination of this age is important because the deuterium profile below a depth of 3,190 m depth does not show the expected correlation with the marine record. Here we present evidence for enhanced 10Be deposition in the ice at 3,160-3,170 m, which we interpret as a result of the low dipole field strength during the Matuyama-Brunhes geomagnetic reversal, which occurred about 780,000 years ago. If correct, this provides a crucial tie point between ice cores, marine cores and a radiometric timescale.
authors.affiliation: Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse, IN2P3-CNRS-Université de Paris-Sud, Bât. 108, 91405 Orsay, France. raisbeck@csnsm.in2p3.fr
authors.forename: G M
authors.initials: GM
authors.lastname: Raisbeck
authors.forename: F
authors.initials: F
authors.lastname: Yiou
authors.forename: O
authors.initials: O
authors.lastname: Cattani
authors.forename: J
authors.initials: J
authors.lastname: Jouzel