Sedimentary Rocks make how much part of earth? A) 50% B) 40% C) 75% D) None of these Related MCQs: Volcanic eruptions occur due to the conversion of rocks in the deeper layers of the earth’s crust to a molten state of? These rocks are rich in fossils? What is the name given to molten rocks that are erupted by a volcano? Rocks that contain fossils are: