Author Question: Which explanation best describes how oceanic crust is formed? A) Continental crust is swallowed ... (Read 123 times)

abc · **on:** Jul 16, 2018

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 2

The oceanic crust has an average age of ________ and a maximum age of ________.

A) 200 million; 400 million
B) 80 million; 200 million
C) 100 million; 180 million
D) 90 million; 300 million