Cosmogenic nuclide & radiometric dating glossary

Glossary of some common terms used in optically stimulated luminescence, radiocarbon and cosmogenic nuclide dating.

AliquotA sub-sample of the material being measured.
AllochthonousRocks that have been transported & deposited (inc. erratics, alluvial fans, gelifluction, etc.
Attenuation length (Λ)Thickness of a material (rock, snow, ice) required to attenuate intensity of cosmic-ray flux due to scattering & energy absorption
AutochthonousRocks that have remained at or near site of formation
ΔRThe local variation in the marine reservoir effect from the global average of 400 years.
DipolarThe Earth’s magnetic field is dipolar, with a north and south pole.
DoseThe amount of energy stored within a crystal as a result of exposure to radiation.
Dose rateThe total radiation dose per unit time that the sample was exposed to during the burial period. Expressed as radiation dose per thousand years (Gy/ky).
Equivalent doseThe laboratory estimate of the radiation dose accumulated throughout the burial period in OSL dating of sediments.
Galactic cosmic radiationEnergetic particles, mostly of protons, originating from outer space.
GyGray, SI unit of radiation dose, used in Optically Stimulated Luminescence dating. I Gy = I J kg-1
IRSLInfra-red stimulated luminescence
InheritanceRetention of remnant cosmogenic nuclides from a previous exposure
IsotopesFamilies of nuclides with the same atomic number
Marine Reservoir Effect (MRE)The concentration of radiocarbon differs between the ocean and the atmosphere, with a ‘reservoir’ in the global oceans. This results in an offset in the radiocarbon age of a sample. The global average MRE is 400 years.
Muon (µ)-ve muons: short-lived energetic lepton particles that decay quickly. Can penetrate rocks to depth.
NuclideAtomic species characterised by a unique number of atomic number and neutron number (e.g., 10Be, which has 4 protons and 6 neutrons)
OSLOptically stimulated luminescence
Partial bleachingLuminescence signals of only a portion of the grains in a sample were fully zeroed prior to burial (typical of glaciofluvial environments)
Production rateRate at which a specific nuclide is produced from a specified element or in a mineral such as quartz. Vary spatially and temporally.
SARSingle aliquot regenerative-dose (for OSL dating)
Spallation reactionNuclear reaction resulting from collision of a highly energetic secondary cosmic ray neutron of energy with a target nucleus.
Terrestrial cosmogenic nuclideA nuclide produced by the interaction of secondary cosmic radiation with exposed target atoms in earth-surface materials.
Glossary from: Davies, B.J., 2021. Dating Glacial Landforms II: Radiometric Techniques, in: Haritashya, U. (Ed.), Cryospheric Geomorphology. Elsevier, pp. 249-280. (link)

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