Author Question: The ________ is solid and very iron rich. A) crust (continental) B) crust (oceanic) C) mantle ... (Read 65 times)

EAugust · **on:** Jul 16, 2018

The ________ is solid and very iron rich.

A) crust (continental)
B) crust (oceanic)
C) mantle
D) core (outer)
E) core (inner)

Question 2

Explain the origin of oceanic crust.

What will be an ideal response?

Cnarkel · **Reply #1 on:** Jul 16, 2018

Answer to Question 1

Answer: E

Answer to Question 2

Answer: It is perhaps a bit surprising that the formation of the basaltic oceanic crust, despite its relative inaccessibility beneath the oceans, is better understood than that of continental crust. The recipe for making basaltpartial melting of mantle peridotite produces basaltic magma. The non-melted peridotite minerals remain behind to make up the mantle part of the lithosphere. Oceanic crust, therefore, simply is extracted from the mantle by partial melting and crystallization. This melting and extraction process is witnessed today at divergent plate boundaries and where mantle plumes generate accumulations of basalt at places such as Hawaii.