Question

which process forms mid-ocean ridges?
earthquakes create long fractures in oceanic crust.
the weight of ocean floor sediments crumples oceanic crust.
the oceanic crust separates and allows mantle material to surface.
plumes of thermal energy cause the oceanic crust to heat and swell.

Explanation:

Mid - ocean ridges are formed at divergent plate boundaries. At these boundaries, the oceanic crust moves apart (separates). This separation creates a gap through which mantle material (magma) can rise to the surface.

• Option 1: Earthquakes are more associated with plate movements (like at transform or convergent boundaries) and don't form mid - ocean ridges.
• Option 2: The weight of ocean floor sediments does not crumple the oceanic crust to form mid - ocean ridges.
• Option 4: Plumes of thermal energy causing the oceanic crust to heat and swell is related to hotspots (like island formation) rather than mid - ocean ridge formation.

Answer:

C. The oceanic crust separates and allows mantle material to surface.