%0 Journal Article %T Geochemical Constraints on the Size of the Moon-Forming Giant Impact %+ Institut de Physique du Globe de Paris (IPGP (UMR_7154)) %+ Ecole Polytechnique Fédérale de Lausanne (EPFL) %+ Arizona State University [Tempe] (ASU) %A Piet, Hélène %A Badro, James %A Gillet, Philippe %< avec comité de lecture %@ 0094-8276 %J Geophysical Research Letters %I American Geophysical Union %V 44 %N 23 %P 11,770-11,777 %8 2017 %D 2017 %R 10.1002/2017GL075225 %K EARTHS CORE %K OXIDATION-STATE %K MAGMA OCEAN %K CORE FORMATION %K SOLAR-SYSTEM %K SIDEROPHILE ELEMENTS %K EARLY DIFFERENTIATION %K TERRESTRIAL PLANET FORMATION %K HF-W CHRONOMETRY %K ACCRETION %Z Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] %Z Sciences of the Universe [physics]/Earth Sciences/GeochemistryJournal articles %X Recent models involving the Moon-forming giant impact hypothesis have managed to reproduce the striking isotopic similarity between the two bodies, albeit using two extreme models: one involves a high-energy small impactor that makes the Moon out of Earth's proto-mantle; the other supposes a gigantic collision between two half-Earths creating the Earth-Moon system from both bodies. Here we modeled the geochemical influence of the giant impact on Earth's mantle and found that impactors larger than 15% of Earth mass result in mantles always violating the present-day concentrations of four refractory moderately siderophile trace elements (Ni, Co, Cr, and V). In the aftermath of the impact, our models cannot further discriminate between a fully and a partially molten bulk silicate Earth. Then, the preservation of primordial geochemical reservoirs predating the Moon remains the sole argument against a fully molten mantle after the Moon-forming impact. %G English %2 https://insu.hal.science/insu-02558677/document %2 https://insu.hal.science/insu-02558677/file/2017GL075225%281%29.pdf %L insu-02558677 %U https://insu.hal.science/insu-02558677 %~ INSU %~ AFRIQ %~ CNRS %~ IPGP %~ USPC %~ UNIV-PARIS