Δ13C

Measure of relative carbon-13 concentration in a sample

In geochemistry, paleoclimatology, archaeology, and paleoceanography, δ13C (pronounced "delta carbon thirteen") is a normalized ratio of the two stable isotopes of carbon—13C and 12C—reported in parts per thousand (per mille, ‰). The definition is, in per mille: δ C 13 = ( ( C 13 / C 12) s a m p l e ( C 13 / C 12) s t a n d a r d − 1) × 1000 {\displaystyle \delta {\ce {^{13}C}}=\left({\frac {({\ce {^{13}C}}/{\ce {^{12}C}})_{\mathrm {sample} }}{({\ce {^{13}C}}/{\ce {^{12}C}})_{\mathrm {standard} }}}-1\right)\times 1000} where the standard is an established reference material. The δ13C of a given compound can vary based on the sources of the precursor material and the biogeochemical processes it has undergone.

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