The oceanic crust is composed almost entirely of ________ rocks that are underlain by ________ rocks, which makes up the lithospheric mantle.
A)felsic; sediments
B)intermediate; felsic
C)sedimentary; mafic
D)mafic; ultramafic

Question

Quizplus · Accepted Answer

The oceanic crust is primarily composed of mafic rocks, such as basalt and gabbro, which are underlain by denser ultramafic rocks in the lithospheric mantle. Choice A is incorrect because felsic rocks are not typically found in oceanic crust. Choice B is incorrect because intermediate rocks are less common in oceanic crust compared to mafic rocks. Choice C is incorrect because sedimentary rocks do not make up the majority of oceanic crust.

The Oceanic Crust Is Composed Almost Entirely of ________ Rocks