Which explanation best describes how oceanic crust is formed?
A) Continental crust is swallowed by the sea at subduction zones.
B) Oceanic crust is extracted from the mantle by partial melting and crystallization.
C) Oceanic crust crystallizes in the core and is pushed up through volcanic pipes.
D) Oceanic crust formed when magma ocean cooled and has remained unchanged except around plate boundaries and at hot spots.

Question

Quizplus · Accepted Answer

Oceanic crust is formed through a process called seafloor spreading, where magma rises to the surface at mid-ocean ridges and cools to form new crust. This process is driven by tectonic plate movement, and as the new crust forms, older crust is pushed away and eventually subducted back into the mantle at subduction zones.

Which Explanation Best Describes How Oceanic Crust Is Formed