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THE PARSA ENSTATITE CHONDRITE
Author(s) -
Bhandari N.,
Shah V.B.,
Wasson John T.
Publication year - 1980
Publication title -
meteoritics
Language(s) - English
Resource type - Journals
eISSN - 1945-5100
pISSN - 0026-1114
DOI - 10.1111/j.1945-5100.1980.tb00526.x
Subject(s) - chondrite , enstatite , meteorite , geology , chondrule , mineralogy , geochemistry , chemistry , analytical chemistry (journal) , astrobiology , environmental chemistry , physics
Two meteoritic stones weighing roughly 600 and 200 g fell on 14 April 1942 near Parsa, Bihar, India. The meteorite is a high‐Fe (EH) enstatite chondrite on the basis of its large abundance of chondrules, its low concentrations of refractory elements, the Si content of its metal (25–30 mg/g), and its enstatite composition Mg 0.975 Ca 0.007 Fe 0.018 . The high contents of Zn, Cd and In suggest that Parsa is petrologic type 4. A unique feature is an irregular nodule of coarse enstatite, several cm long which is chemically different in its Ca and Fe content compared to the matrix. We have increased the elemental concentrations by 10% to allow for terrestrial oxidation and hydration. The revised siderophile and moderately volatile element concentrations fall within the range observed in EH chondrites and mostly outside the range found in EL chondrites. Terrestrial alteration is indicated by the presence of limonite and other hydrated minerals as well as the morphologies revealed by scanning electron microscopy. The 26 Al activity is 51 ± 6 dpm/kg consistent with the calculated production rate. Cosmogenic track densities combined with the 21 Ne, 38 Ar exposure age of 17 Myr indicate 4–10 cm ablation loss, or a preatmospheric mass of about 40 kg.