Lubricating plate tectonics with sediments

An understanding of how plate tectonics began on Earth and which factors controlled its evolution remains debated. Stephan Sobolev and Michael Brown propose that the rise of continents and the accumulation of sediments at continental edges and in trenches, since about three billion years ago, provided lubrication for the stabilization of subduction, and so played a crucial role in the emergence and evolution of plate tectonics on Earth. The authors conclude that the largest surface erosion and subduction lubrication events occurred after the Palaeoproterozoic Huronian global glaciations, leading to the formation of the Columbia supercontinent, and again after the Neoproterozoic ‘snowball’ Earth glaciations. Following the ‘boring billion’, about 1.7 to 0.7 billion years ago—a period of reduced plate tectonic activity, probably due to a low supply of continental sediments to the trenches—the ‘snowball’ Earth event kick-started the modern episode of active plate tectonics.