Earth's crust today has a surprisingly similar composition to the planet's first outer shell, or "protocrust," new research ...

At the initial stage of subduction, the seafloor had just finished spreading ... These interpreted deformation profiles were utilized in the inversion process for determining the best-fitting flexural ...

"They are evolving by themselves, simply through the process of subduction of oceanic crust." That doesn't mean there isn't dense material from Earth's youth at the bottom of the mantle ...

Giant regions of the mantle where seismic waves slow down may have formed from subducted ocean crust, a new study finds.