Question

Spreading centers are where new ______ lithosphere is created, and ______ zones are where older oceanic crust descends into the mantle and is recycled.

Answer 1

The correct answer is oceanic; subduction

The lithosphere layer is above the asthenosphere, a layer that presents the rocks in a more pasty state, due to the high temperatures present inside the planet. The meeting zone between the lithosphere and the asthenosphere has an isotherm, that is, a constant temperature, which is approximately 1,200ºC. Thus, everything above this point of contact has sufficient temperatures to make the rocks remain rigid.