Mass-independent fractionation of oxygen isotopes during thermal decomposition of carbonates

摘要

Nearly all chemical processes fractionate ~17O and ~18O in a mass- dependent way relative to ~16O, a major exception being the formation of ozone from diatomic oxygen in the presence of UV radiation or electrical discharge. Investigation of oxygen three isotope behavior during thermal decomposition of naturally oc- curring carbonates of calcium and magnesium in vacuo has re- vealed that, surprisingly, anomalous isotopic compositions are also generated during this process.