Surface exposure dating with cosmogenic nuclides newnandating com
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].Sampling and dating boulders in a transect down a mountain will rapidly establish how thick your ice sheet was and how quickly it thinned during deglaciation.Sampling strategy is the most important factor in generating a reliable exposure age.Several factors can affect cosmogenic nuclide dating: rock type, attenuation of cosmic rays, topographic shielding, post-depositional movement, and burial and cover by snow, vegetation or earth.Glacial geologists use this phenomenon to date glacial landforms, such as erratics or glacially transported boulders on moraines or glacially eroded bedrock.
Cosmogenic nuclides are rare nuclides that form in surface rocks because of bombardment by high-energy cosmic rays.
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.
Cosmogenic nuclide dating can also be used in this context to understand past ice-sheet thicknesses and changes in subglacial thermal regime.
Different isotopes are used for different lengths of times.
This long period of applicability is an added advantage of cosmogenic nuclide dating.