Depleted mantle

Abstract

The depleted mantle forms by partial melting of the upper mantle at mid-ocean ridges and hot spots. Partial melting “depletes” the residual mantle in incompatible elements and preferentially incorporates them into the generated melt. Hence mantle from which basaltic melt has been extracted in one or multiple melting events is defined as “depleted mantle.” The large-scale plate tectonic cycle of mantle melting, ocean crust generation, and subsequent subduction at convergent margins forms the backbone of silicate Earth evolution. Knowledge of the composition and mass fraction of the depleted mantle is therefore key for assessing global geochemical cycles and for understanding the compositional evolution and differentiation of our planet.