Cosmogenic surface exposure dating
It is particularly useful in Antarctica, because of a number of factors: Cosmogenic nuclide dating is effective over short to long timescales (1,000-10,000,000 years), depending on which isotope you are dating.
Different isotopes are used for different lengths of times.
Trimlines can therefore also be used to reconstruct past ice sheet thickness.
However, this can be difficult, as thermal boundaries within the ice sheet may mean that it is more erosive lower down than higher up, and that cold, non-erosive ice on the tops of mountains may leave in tact older landscapes.
Glacial geologists use this phenomenon to date glacial landforms, such as erratics or glacially transported boulders on moraines or glacially eroded bedrock.Once exposed to the atmosphere, the boulder will begin to accumulate cosmogenic nuclides.Assuming that the boulder remains in a stable position, and does not roll or move after deposition, this boulder will give an excellent As well as using cosmogenic nuclide dating to work out the past extent of ice sheets and the rate at which they shrank back, we can use it to work out ice-sheet thicknesses and rates of thinning[5, 6].Cosmogenic nuclide dating can also be used in this context to understand past ice-sheet thicknesses and changes in subglacial thermal regime.Sampling strategy is the most important factor in generating a reliable exposure age.