FOSSIL TRACK STUDIES OF THE OMOLON PALLASITE CRYSTALS

The olivine and stanfildite crystals from Omolon pallasite meteorite w ere selected from some residue and from locations of an about 150 g fr agment of that meteorite in the Meteoritic Committee, Moscow, Russia. The radiation age of Amnion pallasite was determined to be about 78 MY The olivine crystals were mounted in epoxy resin, polished and etched in Krishnaswami solution, modified by adding 30 g per liter oxalic ac id. The etching of the olivine crystals was performed in hermetically closed vessels during 36-72 hours at T = 100 degrees C. The measured F e-group track density varies from 3 x 10 (4) up to 2.6 x 10(5) track. cm(-2). The measure in 12 Fe-group track rich olivine 43 track due to VVH nuclei were found. It means that the depth of ablation of Omolon m eteorite does not exceed (8.2 +/- 2.1) cm out of preatmospheric surfac e for the most favourable locations.