Under pressure, right mix of rocks and water mimics origins of landmasses
New experiments have re-created the genesis of Earth’s first continents.
By putting the squeeze on water and oceanic rocks under intense heat, researchers produced material that closely resembles the first continental crust, created around 4 billion years ago. The work suggests that thick slabs of oceanic crust helped build the first continents: After plate tectonics pushed the thick slabs underground, the rocks melted, transformed and then erupted to the surface to make continents, the researchers report online August 31 in Geology.
This continental origin story relies on two characteristics that make Earth unlike other rocky planets in the solar system, says study coauthor Alan Hastie, a geologist at the University of Birmingham in England. Earth has both oceans and a network of shifting tectonic plates that can force sections of the planet’s exterior underground, a