Volume 10, Issue 9 p. 795-798
A Meteorite From the Moon

Meteorite ALHA81005: Petrology of a new lunar highland sample

First published: September 1983
Citations: 8


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.