Systematics of Ti isotopes in carbonaceous chondrite whole‐rock samples

Titanium isotopic compositions in whole‐rock samples are reported for meteorites from all four carbonaceous chondrite classes. Characteristic isotopic patterns are derived for each class, since meteorites in a given class usually, though not always, give the same pattern. No anomalies are resolved at the 47/46 and 48/46 ratios, but small 50 excesses are prevalent [ε(50/46) mean values are CI=+1.0±0.8; CM=+2.4±0.6; CO=+3.0±0.5; CV=+3.3±0.5]. Among the three classes where Ti anomalies are clearly present, the mean values for the 50 excesses are the same within the uncertainties. In contrast, the CI class gives just a hint of a 50 excess. Available data, including analyses of Murchison (CM) density separates, suggest that anomalous Ti is not confined to phases in refractory inclusions. Kakangari, a petrologically and chemically peculiar meteorite, shows a clear deficit of 50, thereby supporting a previous suggestion that it is a unique carbonaceous chondrite.