TEM-EELS STUDY OF TITANIUM OXIDATION STATE IN METEORITIC HIBONITES.

Three CAIs within two petrographic thin sections of chondrites Acfer 182 (CH; PL01036) and one of Dar al Gani (DAG) 203 (CO3; PL96274) were analyzed with a JEOL JXA-8200 electron microprobe. Electron-transparent sections of one hibonite grain from each CAI have been prepared using a FEI Quanta 3D FEG focused ion beam. Hibonites with the same compositions as the selected meteoritic crystals were also synthesized from oxide mixtures at 1430°C for 12 h both in air and under controlled