The elevation of the rock

Cosmogenic dating wiki

This can result in a complex exposure history. This varies with altitude and latitude.

Ian Hey Cosmogenic nuclide production rates vary according to latitude and elevation. Dating just one boulder from a moraine may therefore be an unreliable method to rely on. The lower limit for application of the method seems to be about ten years, because of practical limits on the accuracy with which we can measure the quantities of the relevant isotopes. Once exposed to the atmosphere, the boulder will begin to accumulate cosmogenic nuclides. Each of these nuclides is produced at a different rate.

These factors must be measured by the scientist, and are accounted for in the calculation of the exposure age. Cosmogenic nuclides such as these are produced by chains of spallation reactions.

They use a hammer and chisel to sample the upper few centimetres of the rock. These spallation reactions decrease with depth. 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. Solifluction is common in periglacial environments, and can result in rolling, burial and movement of boulders on slopes. This is crucial data for numerical ice sheet models.

These factors must be measured by

Scientists must therefore carefully measure the horizon line all for degrees all around their boulder. Burial dating uses the radioactive decay of two elements to find the age when a sediment was buried away from cosmic rays.

Cosmogenic nuclides such as these are