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Ararki (L5) chondrite: The first meteorite find in Thar Desert of India
Author(s) -
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.,
FRANCHI I. A.
Publication year - 2008
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/j.1945-5100.2008.tb00683.x
Subject(s) - meteorite , meteoroid , chondrite , ordinary chondrite , geology , geochemistry , parent body , cosmic ray , astrobiology , astrophysics , physics
— 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 22 Na indicate that the meteorite fell to Earth more than a decade ago. The cosmic‐ray exposure age based on cosmogenic 21 Ne is 7.2 Ma. Low density of cosmic‐ray heavy nuclei tracks, low 26 A1 activity, the shielding parameter [( 22 Ne/ 21 Ne) 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‐ 4 He and K‐ 40 Ar are 1.1 and 0.58 Ga, respectively, suggesting a heating and degassing event late in the history of this meteorite.