title: Mineralogic and petrologic implications of viking geochemical results from Mars: interim report.
abstract: Chemical results from four samples of martian fines delivered to Viking landers 1 and 2 are remarkably similar in that they all have high iron; moderate magnesium, calcium, and sulfur; low aluminum; and apparently very low alkalies and trace elements. This composition is best interpreted as representing the weathering products of mafic igneous rocks. A mineralogic model, derived from computer mixing studies and laboratory analog preparations, suggests that Mars fines could be an intimate mixture of about 80 percent iron-rich clay, about 10 percent magnesium sulfate (kieserite?), about 5 percent carbonate (calcite), and about 5 percent iron oxides (hematite, magnetite, maghemite, goethite?). The mafic nature of the present fines (distributed globally) and their probable source rocks seems to preclude large-scale planetary differentiation of a terrestrial nature.
authors.forename: A K
authors.initials: AK
authors.lastname: Baird
authors.forename: P
authors.initials: P
authors.lastname: Toulmin
authors.forename: B C
authors.initials: BC
authors.lastname: Clark
authors.forename: H J
authors.initials: HJ
authors.lastname: Rose
authors.forename: K
authors.initials: K
authors.lastname: Keil
authors.forename: R P
authors.initials: RP
authors.lastname: Christian
authors.forename: J L
authors.initials: JL
authors.lastname: Gooding