Tiny minerals may have shaped Earth’s first plate boundaries

Weakened rock may explain the origin of plate tectonics, a simulation finds

CRACKING EARTH’S SKIN  Intermittent weakening of corridors of crust on early Earth could have created plate boundaries through proto-subduction, a new simulation finds. Once weak zones became established plate boundaries, a plate could move and rotate, something like the present-day Pacific plate. The plate’s movement is evidenced by the sharp bend in the Emperor-Hawaiian island chain, a series of volcanoes that includes the Hawaiian Islands. The warm colors mark the plate boundaries.

D. Bercovici

The first ruptures in early Earth’s skin formed because of the weakness of rock minerals merely a millimeter wide, two scientists propose.