Question

Molten rock produced in the mantle and extruded at a divergent boundary (mid-ocean ridge) is most likely ______ in composition and will produce the extrusive igneous rock ______.

A)

felsic, granite

B)

intermediate, diorite

C)

mafic, basalt

Answer 1

C. mafic, basalt

Step-by-step explanation:

The molten rock produced in the mantle and extruded at a divergent boundary, i.e., mid-ocean ridge, is most likely mafic in composition and will have the extrusive igneous rock basalt. Mid-ocean ridges are divergent boundaries where plates move away from each other, resulting in the upwelling of magma from the mantle. The magma that is produced in the mantle is mafic in composition. Mafic magma is low in silica content and rich in magnesium and iron, which gives it a darker color and a higher density. When mafic lava cools down rapidly on the ocean floor, it forms extrusive igneous rock basalt. Basalt is the most common extrusive igneous rock found at mid-ocean ridges. It has a fine-grained texture, dark color, and high density.