What causes the melting that provides the basalt lava extruded at mid-ocean ridges and along rifts?  A. Circulation of superheated oceanic water travels through the subsurface, melting the surrounding crust. B. Melting is due to hot mantle rock rising to shallow depths beneath the ridge, which subsequently undergoes decompression melting. C. Melting is the result of adjacent volcanoes that are at higher melting temperatures than the mid-ocean ridges. D. Flux melting of the asthenosphere creates basaltic magma. Part 2 (1 point) Unlike mid-ocean ridges, some continental rift volcanoes also produce felsic pyroclastic debris. Why? Choose one: A. Because as basalt rises through continental crust, heat transfer partially melts the continental crust, creating a felsic magma. B. Because the material is directly from the lower mantle. C. Because felsic magma rises from the mantle into the continental crust. D. Because there is no basalt beneath the continent.