Geology (2013)

Crustal recycling probably peaked about 1.1–1.2 billion years ago, according to geochemical analyses of magmatic rocks from across the globe.

Martin J. Van Kranendonk at the University of New South Wales, Australia, and Christopher Kirkland at the Geological Survey of Western Australia assessed the concentrations of the elements zirconium and thorium from rocks in Western Australia. They combined their results with a database of elemental abundances and oxygen isotope values of grains of the mineral zircon from around the world. The data show that the concentration of these elements and oxygen isotope values — geochemical markers of crustal recycling — began to rise about 3 billion years ago. The indicators peaked around 1.1–1.2 billion years ago, coincident with the assembly of the supercontinent Rodinia. At that time, tectonic plates were already large, but the mantle was warmer and convection was probably faster. The plates drifted across the Earth at faster rates, leading to unprecedented rates of crustal recycling and a climax in continental collisions.

The subsequent cooling of the Earth's mantle slowed the drift of the plates, limiting rates of plate collision and crustal recycling.