Cosmogenic nuclides are produced when cosmic radiation bombards particles in the atmosphere, like oxygen and nitrogen. These interactions directly produce "meteoric" isotopes beryllium-10 (10Be) and beryllium-7 (7Be). These reactions in the atmosphere also produce secondary cosmic radiation in the form of neutrons and muons. These secondary particles travel down to Earth's surface where they interact with atoms in minerals like quartz. This interaction with silicon atoms produces "in situ" 10Be. When rock is first exposed at or near Earth's surface, it begins accumulating 10Be. Therefore, the concentration of 10Be in quartz is a proxy for the amount of time the rock or sediment has been sitting there.

10Be has a half-life of 1.4 million years (Chmeleff et al., 2010), so the concentration of 10Be in quartz is a balance between its production and decay. This is timescale is particularly useful for reconstructing the extent of ancient glaciers and ice sheets over now ice-free landscapes. We can also calculate the rates at which landscapes are eroding from measurements of 10Be measured in sediment and rocks.