The building blocks of continental crust: Evidence for a major change in the tectonic setting of continental growth at the end of the Archean

Abstract Oceanic arcs are commonly cited as primary building blocks of continents, yet modern oceanic arcs are mostly subducted. Also, lithosphere buoyancy considerations show that oceanic arcs (even those with a felsic component) should readily subduct. With the exception of the Arabian–Nubian orogen, terranes in post-Archean accretionary orogens comprise  50%) produced in continental arcs. Felsic igneous rocks in oceanic arcs are depleted in incompatible elements compared to average continental crust and to felsic igneous rocks from continental arcs. They have lower Th/Yb, Nb/Yb, Sr/Y and La/Yb ratios, reflecting shallow mantle sources in which garnet did not exist in the restite during m…

Penrose Conference Report: When Did Plate Tectonics Begin?

When did plate tectonics begin? Evidence from the geologic record

When Did Plate Tectonics Begin on Earth? Theoretical and Empirical Constraints