Oxygen isotopes in calcium¯aluminum-rich inclusions from enstatite chondrites: new evidence for a single CAI source in the solar nebula

Calcium¯aluminum-rich inclusions (CAIs) from enstatite chondrites have large 16O excesses, similar to CAIs in carbonaceous and ordinary chondrites, and are also similar in morphology, mineralogy and Al¯Mg isotopic systematics. These similarities provide new evidence that most CAIs might have formed in a single, restricted nebular locale and were then distributed unevenly throughout the various chondrite accretion regions.