ABSTRACT

Professor Jeffrey Vervoort, Washington State University: Growth of Earth’s earliest continental crust

A fundamental principle of Earth’s geochemical evolution holds that continental crust is formed by extraction of melts from the mantle, leaving part of the mantle depleted in incompatible elements. Radiogenic isotopes, specifically the Sm-Nd and Lu-Hf systems, have been essential tools in revealing this evolution, although the mechanisms and volumes of mantle depletion and crustal production through time are hotly debated. In this talk, I will review the geochemical observations, their interpretations and advance a unified theory for changes in Earth’s mantle – crust dynamics during the early Earth leading to plate tectonics as it operates today.