Volcanic rocks form from
A)the eruption of viscous magma.
B)partial melting of basalt.
C)solidification of lava.

Question

Quizplus · Accepted Answer

Volcanic rocks form from the solidification of lava, which is molten rock that has flowed out onto the Earth's surface. This can happen during non-explosive eruptions where lava flows out of the volcano or during explosive eruptions where pyroclastic material is ejected and cools to form volcanic rock. While the viscosity of magma can influence the style of eruption, it is not the defining factor in the formation of volcanic rocks. Basaltic magma can also solidify to form volcanic rocks, but this process still involves the solidification of lava rather than partial melting.

Volcanic Rocks Form from