While the ultramafic rock, peridotite, comprises the bulk of the mantle, the earth hasn't been hot enough to make much ________ (its volcanic equivalent)since the Precambrian.
A)andesite
B)gabbro
C)komatiite
D)welded tuff

Question

Quizplus · Accepted Answer

Komatiite is the volcanic equivalent of peridotite and was only produced in significant amounts during the early history of the Earth when temperatures were much hotter than they are today. Andesite, gabbro, and welded tuff are all volcanic rocks but are not directly related to peridotite or the mantle.

While the Ultramafic Rock, Peridotite, Comprises the Bulk of the Mantle