古老岩石揭示早期板块运动

Earth had variable tectonic plate motions and a strong, stable magnetic field 3.5 billion years ago Claire Nichols T he movement of tectonic plates—massive slabs of rock—over Earth’s surface controls the planet’s habitability by sustaining the carbon cycle that regulates the climate and stabilizes liquid wa- ter at the surface (1). It also facilitates efficient planetary heat loss, thereby maintaining convection in Earth’s core and the generation of a magnetic field. The presence of a magnetosphere—a space around Earth domi- nated by its magnetic field—provides shielding from solar and cosmic radiation and mediates the loss of atmospheric gas into space (1). …