The existence of mantle plumes was first proposed in the 1970s to explain intra-plate,
hotspot volcanism, yet owing to difficulties in resolving mantle upwellings with geophysical …

Basaltic volcanism'samples' the Earth's mantle to great depths, because solid-state
convection transports deep material into the (shallow) melting region. The isotopic and trace …

Crustal recycling at convergent plate boundaries is essential to mantle heterogeneity.
However, crustal signatures in the mantle source of basaltic rocks above subduction zones …

The lower plate is the dominant agent in modern convergent margins characterized by
active subduction, as negatively buoyant oceanic lithosphere sinks into the asthenosphere …

We report analyses of the 176Hf 177Hf ratio for 25 chondrites from different classes of
meteorites (C, O, and E) and the 176Lu 177Hf ratio for 23 of these as measured by plasma …

Carbonate, the major carbon reservoir on Earth's surface, can enter into the mantle by
subduction. However, evidence for recycled surficial carbonates in the deep mantle is still …

A mantle value of∼ 17.5 for Nb/Ta appears well established; less well established are
crustal values of∼ 11–12, although it appears that Nb/Ta for crustal-derived melts is less …

Ubiquitous heterogeneity in the Earth's mantle has been documented by numerous
chemical and isotopic analyses of oceanic basalts. Despite the ever-increasing amount of …

We report new Hf (and Nd) data for more than 100 sedimentary samples, recent to Archean
in age, from a wide range of depositional environments. These data document the behavior …

Abstract Early History of Mantle GeochemistryUntil the arrival of the theories of plate
tectonics and seafloor spreading in the 1960s, the Earth's mantle was generally believed to …