Question

Oceanic lithosphere thickens away from the mid-ocean ridge primarily due to ________. A. the addition of new crust due to hot-spot volcanism B. the addition of new crust due to sedimentation C. the addition of new lithospheric mantle as a result of cooling D. reasons that geologists cannot determine at present

Answer 1

Answer:

C. the addition of new lithospheric mantle as a result of cooling

Explanation:

• The oceanic lithosphere is a part of the asthenosphere and the upper mantle and its thickness depend on the distance away for the mid-oceanic ridges.

• This is evident from the studies of the seafloor spreading and the cooling of the plates and rocks masses. As the hot magma upwells and then cools at a certain degree and the cooled plates move away from the center.