Isotopic constraints on the formation and evolution of the Earth-Moon system
Isotopes are useful probes of planet formation and evolution for at least two reasons. Some exhibit nucleosynthetic anomalies providing clues to their original location. Others undergo decay, providing age constraints. In this talk, I’ll discuss two applications of these ideas. The fact that the silicate Earth records different fractions of “carbonaceous” material in different elements implies that it experienced a change in the material it was accreting over time. The first ~95% was “non-carbonaceous”, while the last ~5% was “carbonaceous” and volatile-rich. Reconciling these constraints with existing planetary accretion scenarios is not easy. In the second part, I’ll discuss the idea that the pile-up of lunar ages around 4.35 Gyr is not the signature of magma ocean crystallization but is instead related to a tidal heating event. This story allows the Moon to be older (~4.45 Gyr or so), which is easier to reconcile with dynamical models.
Date: 28 February 2025, 13:00
Venue: Department of Earth Sciences, South Parks Road OX1 3AN
Venue Details: Seminar Rooms
Speaker: Prof Francis Nimmo (UC Santa Cruz)
Organising department: Department of Earth Sciences
Part of: Earth Sciences departmental seminars
Booking required?: Not required
Booking url: https://earth.web.ox.ac.uk/event/isotopic-constraints-on-the-formation-and-evolution-of-the-earth-moon-system
Audience: Public
Editor: Maria Petrunova