title: Abundance of alkali metals, alkaline and rare earths, and strontium-87/ strontium-86 ratios in lunar samples.
abstract: The variation in trace element abundance patterns indicates that lunar igneous rocks are the product of extensive igneous fractionation. Variations in the Sr(87)/ Sr(86) ratio indicate that these rocks crystallized 3.5+/-0.3 x 10(9) years ago.
authors.forename: P W
authors.initials: PW
authors.lastname: Gast
authors.forename: N J
authors.initials: NJ
authors.lastname: Hubbard