Evolution of the deep Earth mantle : message from the hottest melts- komatiites
Laboratoire(s)/équipe(s) du LabEx OSUG impliqué(e.s) : ISTerre, IPAG
Porteur du projet : Alexander SOBOLEV
Komatiites are the hottest and deepest mantle-derived melts. The current project is based on our recent discovery of a deep Earth hydrous reservoir in the Archean, made by deciphering the composition of melt included in olivine in komatiites from the 2.7 Ga Abitibi belt in Canada (Sobolev et al, Nature, 2016). The project addresses the origin and evolution of this deep Earth hydrous reservoir and its connection to the onset of plate tectonics early in Earth history. To constrain the long-term evolution of mantle composition and temperature, we will extend our approach in time and space by studying komatiites with ages from 3.6 Ga to 90 Ma. We will follow two lines of research : (1) analysis of olivine phenocrysts and their spinel and melt inclusions from type localities of komatiites of different ages and (2) experimental development of geothermometers and oxybarometers for high-temperature and high magnesian melts.
Soutien attribué en 2017 : 20 000 €