Quantitative estimates of impact induced crustal erosion during accretion and its influence on the Sm/Nd ratio of the Earth
Résumé
Dynamical scenarios of terrestrial planets formation involve strong perturbations of the inner part of the solar system by the giant-planets, leading to enhanced impact velocities and subsequent collisional erosion. We quantitatively estimate the effect of collisional erosion on the resulting composition of Earth, and estimate how it may provide information on the dynamical context of its formation. The composition of the Bulk Silicate Earth (BSE, Earth's primitive mantle) for refractory and lithophile elements (RLE) should be strictly chondritic as these elements are not affected by volatile loss nor by core formation. However, an excess in 142 Nd compared to the 144 Nd has been emphasized in terrestrial samples compared to most measurements in chondrites.
Domaines
Planète et Univers [physics]
Origine : Fichiers produits par l'(les) auteur(s)