Ararki (L5) chondrite: The first meteorite find in Thar Desert of India

Bhandari, N.; Murty, S. V. S.; Shukla, P. N.; Mahajan, R. R.; Shukla, A. D.; Lashkari, G.; Sisodia, M. S.; Tripathi, R. P.; Parthasarathy, G.; Verma, H. C. and Franchi, I. A. (2008). Ararki (L5) chondrite: The first meteorite find in Thar Desert of India. Meteoritics and Planetary Science, 43(4) pp. 761–770.

URL: http://digitalcommons.library.arizona.edu/holdings...

Abstract

We report here a chance find of a meteorite in the sand dunes of Ararki village of Hanumangarh district in the Rajasthan desert of northwest India. Chemical and petrological evidence in conjunction with isotopic composition of oxygen indicate that it is an L5 chondrite. The fayalite content of olivines is 26.3 mol%. The meteorite has some serpentinized olivines and 0.3% carbon having a terrestrial isotopic composition, indicating that it is moderately weathered. The absence of 22Na indicate that the meteorite fell to Earth more than a decade ago. The cosmic-ray exposure age based on cosmogenic 21Ne is 7.2 Ma. Low density of cosmic-ray heavy nuclei tracks, low 26Al activity, the shielding parameter [(22Ne/21Ne)C = 1.094] and absence of neutron capture effects indicate cosmic-ray shielding in a meteoroid having radius of about 16 cm, implying a meteoroid mass of about 60 kg and ablation of about 93%. The gas retention ages, based on U/Th-4He and K 40Ar are 1.1 and 0.58 Ga, respectively, suggesting a heating and degassing event late in the history of this meteorite.

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