text: As seen in the table above, there are a wide variety of useful cosmogenic nuclides which can be measured in soil, rocks, groundwater, and the atmosphere. These nuclides all share the common feature of being absent in the host material at the time of formation. These nuclides are chemically distinct and fall into two categories. The nuclides of interest are either noble gases which due to their inert behavior are inherently not trapped in a crystallized mineral or has a short enough half-life such that it has decayed since nucleosynthesis, but a long enough half-life such that it has built up measurable concentrations. The former includes measuring abundances of Kr and Ar whereas the latter includes measuring abundances of Be, C, and Al.
  Three types of cosmic-ray reactions can occur once a cosmic ray strikes matter which in turn produce the measured cosmogenic nuclides.
  * cosmic ray spallation, which is the most common reaction on the near-surface (typically 0 to 60 cm below) the Earth and can create secondary particles which can cause additional reaction upon interaction with another nuclei called a collision cascade.
  * muon capture, which pervades at depths a few meters below the subsurface because muons are inherently less reactive; in some cases, high-energy muons can reach greater depths
  * neutron capture, which due to the neutron's low energy are captured into a nucleus, most commonly by water, but this process is highly dependent on snow, soil moisture and trace element concentrations.