The mantle is Earth’s largest silicate reservoir and one of its fundamental characteristics is the chemical and isotopic heterogeneity that extends down to the mineral scale. These various-sized mantle domains reflect different proportions of multiple, superimposed depletion and enrichment events that affected the mantle in time and space. As such, each of these domains may therefore retain different and potentially unique information regarding the extent of mantle depletion as well as the role and nature of enrichment by crustal recycling. Owing to the reaction with other surface reservoirs before subduction, mantle domains that were enriched by recycled crust may additionally record ancient ocean-atmospheric conditions. The sustainable mantle thus maintains a certain rate of exchange between Earth’s interior and exterior, stores compositional heterogeneities that relate to this exchange and partly mirror global conditions of ancient Earth’s surface. This session welcomes contributions that address different scales, features and implications of the chemical and isotopic heterogeneity of the mantle, its role for geological resources and the perspective of mantle and mantle-derived components to elucidate ancient surface conditions that shaped a habitable planet over time.
Kirchenbaur, Maria (1); König, Stephan (2)
1: Institute of Mineralogy, Geochemistry, Leibniz University Hannover; 2: Department of Geosciences, University of Tuebingen, Germany