Premium
Itqiy: A metal‐rich enstatite meteorite with achondritic texture
Author(s) -
Patzer Andrea,
Hill Dolores H.,
Boynton William V.
Publication year - 2001
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.1945-5100.2001.tb01841.x
Subject(s) - enstatite , chondrite , chondrule , kamacite , meteorite , geology , achondrite , pyroxene , geochemistry , feldspar , mineralogy , olivine , astrobiology , quartz , physics , paleontology
— Itqiy is a unique coarse‐grained, metal‐rich enstatite meteorite that was found in the Western Sahara and consists of two rocks together weighing 4.72 kg, which are both completely coated with fusion crust. We report results from our electron microprobe and instrumental neutron activation analysis techniques. Itqiy consists of subhedral, equigranular, millimeter‐sized enstatite, −25 vol% of millimeter‐sized kamacite and a few tiny intergrowths of sulfides and kamacite. Relic chondrules are absent. Pyroxene (Fs 0.2 ) is chemically similar to enstatite in EL chondrites, but the metal is closer in composition to that in EH chondrites. Sulfides resemble those in E chondrites but their compositions are distinct from those in both EL and EH chondrites. Itqiy clearly formed under very reducing conditions, but it does not appear to have formed from EH or EL chondrites. Two thermal events can be distinguished. Silicate compositions including rare earth element abundances indicate loss of partial melt and slow cooling. Heterogeneous sulfides indicate a subsequent reheating and quenching event, which may have been due to shock as many enstatite grains show shock stage S3 features.