* Astronomy

Blobrana · L

RE: Omolon meteorite

Blobrana · L

Title: Mineralogy of Olivine-hosted Inclusions from the Omolon Pallasite
Authors: V. V. Sharygin, S. V. Kovyazin and N. M. Podgornykh

The Omolon meteorite (250 kg) was found in 1982 (it fell in 1981) near the Omolon river (Magadan district, Russia). This meteorite belongs to the main group of the pallasite family. It contains rounded olivine grains (about 60 vol. %, sizes - up to 3 cm, Fa content - 12.3 mole %) in nickeloan iron matrix consisting of kamacite, taenite and plessite. In addition, troilite, chromite, schreibersite, nikelphosphide (former rhabdite) and stanfieldite were found in the meteorite. The irradiation time of this meteorite was determined to at 78±7 Ma (by noble gases); the K-Ar age for olivine crystallisation was assessed as 4.6 Ga, i.e., close to the starting time for formation of protoplanetary system. The calculation of atmospheric trajectory and orbit showed that the Omolon meteorite was probably a fragment of an Apollo M-type asteroid and its preatmospheric mass was approximately 390-490 kg. According to fossil track studies the depth of ablation for the Omolon pallasite does not exceed 8.2±2.1 cm out of the preatmospheric surface. It is suggested that glass of the forsteritic composition is present in melting rim of the meteorite.

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Blobrana · L

The Omolon (Pallasite) meteorite fell in Magadanskaya oblast', Russia, on the 16th May, 1981.
A total mass of 250 kg was recovered.

64° 1' 12"N, 161° 48' 30"E

On May 16, 1981 at 5:10 there was a report from a meteorological station of a bright fireball. A mass of 250 kg was found in 1983 by I. Tynavie, who had observed the fall on May 16, 1981. The meteorite was recovered in June 1990.
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