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 …

Well-defined constants of radioactive decay are the cornerstone of geochronology and the
use of radiogenic isotopes to constrain the time scales and mechanisms of planetary …

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 …

Continental crust forms from, and thus chemically depletes, the Earth's mantle. Evidence that
the Earth's mantle was already chemically depleted by melting before the formation of …

Following its subduction, oceanic crust either contributes to the source of island-arc volcanic
rocks or it is recycled into the mantle. Most,, but not all authors believe that recycled crust is …

The parameter μ describes the 238U/204Pb ratio of an Earth reservoir. Mantle domains
labeled HIMU (high μ) originally defined reservoirs with highly radiogenic Pb isotope ratios …

Recycled ancient oceanic crust with variable amounts of aging, or inclusion of sediments of
differing types and origins has often been invoked as a source for present‐day ocean island …

New Hf isotope and trace element data on mid-ocean ridge basalts (MORB) from the Pacific
Ocean basin are remarkably uniform (176Hf/177Hf≈ 0.28313–0.28326) and comparable to …

Recycling of oceanic crust together with different types of marine sediments has become
somewhat of a paradigm for explaining the chemical and isotopic composition of ocean …

Consideration of petrology, geochemistry, and mineral physics suggests that ancient
subducted oceanic crusts cannot be the source materials supplying ocean island basalts …