| Summary: | Cosmogenic nuclide exposure dating of glacial clasts is becoming a common and robust method for reconstructing the history of glaciers and ice sheets. In Antarctica, however, many samples exhibit cosmogenic nuclide ‘inheritance’ as a result of sediment recycling and exposure to cosmic radiation during previous ice free periods. In-situ cosmogenic 14 C, in combination with longer lived nuclides such as 10 Be, can be used to detect inheritance because the relatively short half-life of 14 C means that in-situ 14C acquired in exposure during previous interglacials decays away while the sample locality is covered by ice during the subsequent glacial. Measurements of in-situ 14 C in clasts from the last deglaciation of the Framnes Mountains in East Antarctica provide deglaciation ages that are concordant with existing 26 Al and 10 Be ages, suggesting that in this area, the younger population of erratics contain limited inheritance.
|
|---|