What is the magma source for mid-ocean ridge basalt?
A)decompression melting in the shallowest part of the asthenosphere beneath the ridge
B)by spontaneous melting in mafic magma chambers within oceanic crust
C)along block faults by frictional heating deep in the oceanic lithosphere
D)It all comes from Hawaii then flows out laterally along the ridge system.

Question

Quizplus · Accepted Answer

Mid-ocean ridge basalt is generated by decompression melting in the shallowest part of the asthenosphere beneath the ridge. As mantle rises to shallower depths beneath a mid-ocean ridge due to tectonic spreading, pressure and temperature conditions change, leading to partial melting and the formation of magma. This magma then rises to the surface, solidifies as basalt, and contributes to the growth of the oceanic crust.

What Is the Magma Source for Mid-Ocean Ridge Basalt