The mantle is composed mainly of metallic iron with small amounts of magnesium silicate minerals.

________ destroyed the city of St. Pierre, Martinique in 1902.

The large mineral grains in a porphyritic igneous rock are called ________.

Which statement concerning sedimentary rocks is NOT true?

Parallel, straight, linear imperfections visible on the cleavage surfaces of plagioclase feldspar are called ________.

Basaltic lavas are generally hotter and more viscous than andesite lavas.

Peat is thought to be the original material from which coals are formed.

Which of the following shoreline features forms only in tectonically active areas?

Which was the most powerful, explosive volcanic eruption of historic time?

Aa flows are generally thinner and have smoother surfaces than pahoehoe flows.