title: Heterogeneous accretion and the moderately volatile element budget of Earth.
abstract: Several models exist to describe the growth and evolution of Earth; however, variables such as the type of precursor materials, extent of mixing, and material loss during accretion are poorly constrained. High-precision palladium-silver isotope data show that Earth's mantle is similar in 107Ag/109Ag to primitive, volatile-rich chondrites, suggesting that Earth accreted a considerable amount of material with high contents of moderately volatile elements. Contradictory evidence from terrestrial chromium and strontium isotope data are reconciled by heterogeneous accretion, which includes a transition from dominantly volatile-depleted to volatile-rich materials with possibly high water contents. The Moon-forming giant impact probably involved the collision with a Mars-like protoplanet that had an oxidized mantle, enriched in moderately volatile elements.
authors.affiliation: School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Manchester M13 9PL, UK. maria.schonbachler@manchester.ac.uk
authors.forename: M
authors.initials: M
authors.lastname: Schönbächler
authors.forename: R W
authors.initials: RW
authors.lastname: Carlson
authors.forename: M F
authors.initials: MF
authors.lastname: Horan
authors.forename: T D
authors.initials: TD
authors.lastname: Mock
authors.forename: E H
authors.initials: EH
authors.lastname: Hauri