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Meteorite ALHA81005: Petrology of a new lunar highland sample
Author(s) -
Kurat Gero,
Brandstätter Franz
Publication year - 1983
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl010i009p00795
Subject(s) - anorthosite , basalt , geology , breccia , geochemistry , meteorite , plagioclase , regolith , geology of the moon , achondrite , chondrule , lunar mare , mafic , olivine , pyroxene , petrology , astrobiology , chondrite , paleontology , quartz , physics
Meteorite ALHA81005 is a shock‐compacted lunar highland regolith breccia. Besides glasses (fragments, spherules, matrix glass), chondrules (of ANT composition), and mineral fragments this new lunar sample contains principally three lithologies: 1) A pristine ferroan anorthosite suite consisting of anorthosites, norites, and one plagioclase peridotite. 2) A high‐Mg granulitic breccia suite representing variable mixtures of troctolitic and noritic precursor rocks. 3) A melt‐rock suite consisting of feld‐spathic basalts and metabasalts of a composition intermediate between (1) and (2). Most glass compositions and the chondrule compositions also project into this group. All lithologies and their derivatives are characteristically poor in alkalis. Neither a KREEP nor a mare basalt composition could be identified with certainty. ALHA81005 apparently comes from a highland area far from any mare basalt and KREEP source.