Late accretion on the earliest planetesimals revealed by the highly siderophile elements

Dale, C.W.; Burton, K.W.; Greenwood, R.C.; Gannoun, A.; Wade, J.; Wood, B.J.; Pearson, D.G.

Abstract

Late accretion of primitive chondritic material to Earth, the Moon, and Mars, after core formation had ceased, can account for the absolute and relative abundances of highly siderophile elements (HSEs) in their silicate mantles. Here we show that smaller planetesimals also possess elevated HSE abundances in chondritic proportions. This demonstrates that late addition of chondritic material was a common feature of all differentiated planets and planetesimals, irrespective of when they accreted; occurring ≤5 to ≥150 million years after the formation of the solar system. Parent-body size played a role in producing variations in absolute HSE abundances among these bodies; however, the oxidation state of the body exerted the major control by influencing the extent to which late-accreted material was mixed into the silicate mantle rather than removed to the core.

Citation

Dale, C., Burton, K., Greenwood, R., Gannoun, A., Wade, J., Wood, B., & Pearson, D. (2012). Late accretion on the earliest planetesimals revealed by the highly siderophile elements. Science, 336(6077), 72-75. https://doi.org/10.1126/science.1214967

• Journal Article Type: Article
• Publication Date: Apr 1, 2012
• Deposit Date: Mar 14, 2012
• Publicly Available Date: Apr 26, 2013
• Journal: Science
• Print ISSN: 0036-8075
• Electronic ISSN: 1095-9203
• Publisher: American Association for the Advancement of Science
• Peer Reviewed: Peer Reviewed
• Volume: 336
• Issue: 6077
• Pages: 72-75
• DOI: https://doi.org/10.1126/science.1214967
• Public URL: https://durham-repository.worktribe.com/output/1502457