Isotope anomaly, mass-independent-fractionation, organic matter, photochemistry, self-shielding, solar composition, water
Oxygen has three stable isotopes, oxygen-16, -17, and -18. In most studies on terrestrial samples, only the 18O/16O ratio is usually measured and discussed, where the mass-dependent fractionation law, expressed by δ17O ≈ 0.52 × δ18O, can be safely assumed. The δ17O values among extraterrestrial samples significantly deviate from the above shown relationship. This deviation bears the top-class importance in cosmochemistry, and naturally, in astrobiology.
References and Further Reading
- Clayton RN (2005) Oxygen isotopes in meteorites. In: Davis AM (ed) Meteorites, comets and planets, vol 1, Treatise on geochemistry. Elesevier-Pergamon, Oxford, pp 129–142Google Scholar
- Hashizume K, Takahata N, Naraoka H, Sano Y (2011) Extreme oxygen isotope anomaly with a solar origin detected in meteoritic organics. Nat Geosci (in press)Google Scholar