Cosmogenic isotope dating
Yet, children born when the first paper using cosmogenic nuclides to date such erratics was published (Phillips et al., 1990) are still not old enough to vote. took a simple and oft-used approach for characterizing the vertical extent of now-vanished ice.
They used protruding mountains as chronometric dipsticks (e.g., Stone et al., 2003), analyzing the Al content of submeter erratics left behind as the East Antarctic Ice Sheet lowered.
The former age, although implying early deglaciation for this area of the British ice sheet, is not incompatible with minimum deglaciation ages from other contexts and locations in northwest England.Until just 20 years ago, when pioneering work in accelerator mass spectrometry (Elmore and Phillips, 1987), cosmogenic isotope systematics (Lal, 1988), and geologic applications (Craig and Poreda, 1986; Kurz, 1986) hit the presses, such conclusions were unreachable because many hypotheses regarding rates and dates of glacial processes were simply unfalsifiable.In two short decades, we have learned so much about when glaciers and ice sheets retreated that it's hard to imagine a world where glacial boulders were not targets for dating.Using cosmogenic isotopic analyses of less than two dozen samples, Mackintosh et al. 551–554]) lift the veil of suspicion that has hung over the East Antarctic Ice Sheet.No longer should it be considered a major player in postglacial sea-level rise.