Séminaire Alberto Saal

Salle des séminaires Mardi 20 juin à 14h.

« Magmatic Degassing and the Volatile Budget of the Moon »

Abstract

Establishing the origin of water and other volatiles, and how and when the budgets of these elements were set in planetary bodies during the earliest stages of Solar System evolution has important implications for understanding the genesis and evolution of the terrestrial planets and the origin of life. The Moon provides a frozen record of the first few hundred million years of Solar System evolution and, thus, offers a unique opportunity to establish the origin, budget and timing of the water, and other volatiles, delivery to the terrestrial planets. Presently, there are two distinct views: one, suggesting that the Moon is “bone-dry”, 100 to 1000 times more depleted in highly volatile elements (e.g., water) than Earth. The second view suggests that the Moon is only 5 to 10 times more depleted in highly volatile elements than Earth. Therefore, the estimated extent of the Moon’s volatile depletion differs between the two views by a factor of 20 to 200. We show that  the 20 to 200 factor in the estimated Moon’s volatile depletion might originate from the fact that the degassing of volatile elements during lunar magmatic processes has not been carefully considered.  We have to account for the effect of magmatic degassing  before we can  estimate the extent of volatile depletion of the Moon.