| Few natural fources are as spectacular and threatening, or have played such a dominant role in shaping the face of the Earth, as erupting volcanoes. Volcanism has built some of the world's greatest mountain ranges, covered vast regions with lava (molten rock at the Earth's surface), and triggered explosive eruptions whose size and power are nearly impossible for us to imagine today. Though few people in the United States may actually experience an erupting volcano, the evidence for earlier volcanism is preserved in many rocks of North America. -- Brantley, 1994 |
