Question

material from the mantle could reach the surface and then be reburied until it became molten again describe how this could happen

Answer 1

Weathering and erosion at the earth's surface can break down rocks into small bits. ... old crust through subduction, not all the rock cycling goes back into the mantle. ... continental crust that we commonly describe as mountain ranges or orogens. .... The materials on the channel bottom stay in place until the velocity is large ...