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The moon: Composition determined by nebular processes

The Moon and the Planets

By:
, ,
DOI: 10.1007/BF00897296

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Abstract

The bulk composition of the Moon was determined by the conditions in the solar nebula during its formation, and may be quantitatively estimated from the premise that the terrestrial planets were formed by cosmochemical processes similar to those recorded in the chondrites. The calculations are based on the Ganapathy-Anders 7-component model using trace element indicators, but incorportate improved geophysical data and petrological constraints. A model Moon with 40 ppb U, a core 2% by weight (1.8% metal with ???35% Ni and 0.2% FeS) and Mg/(Fe2++Mg)?????0.75 meets the trace element restrictions, and has acceptable density, heat flow and moment of inertia ratio. The high Ni content of the core permits low-Ti mare basalts to equilibrate with metal, yet still retain substantial Ni. The silicate resembles the Taylor-Jakes?? composition (and in some respects the waif Ganapathy-Anders Model 2a), but has lower SiO2. Minor modifications of the model composition (U=30-35 ppb) yield a 50% melt approximating Apollo 15 green glass and a residuum of olivine plus 3 to 4% spinel; the low SiO2, favors spinel formation, and, contrary to expectation, Cr is not depleted in the liquid. There may no longer be any inconsistency between the cosmochemical approach and arguments based on experimental petrology. ?? 1978 D. Reidel Publishing Company.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
The moon: Composition determined by nebular processes
Series title:
The Moon and the Planets
DOI:
10.1007/BF00897296
Volume
18
Issue:
4
Year Published:
1978
Language:
English
Publisher location:
Kluwer Academic Publishers
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
The Moon and the Planets
First page:
465
Last page:
478
Number of Pages:
14