A volcano is an opening in the earth's surface through which lava, hot gases, and rock fragments erupt. These openings are formed when melted rock from deep in the earth build up around the opening, and form mountains. When these openings erupt they shoot out huge fiery clouds over the mountain, and spew glowing rivers of melted lava down their sides. In some eruptions, red-hot ash and cinders shoot out the mountaintop, and large chunks …showed first 75 words of 1201 total…

…showed last 75 words of 1201 total…domes. Finally, volcanoes are still one of the many amazing features on this Earth, and serve as a "window" to earth's interior. The materials that erupt help scientists learn more about the conditions within the earth. We still don't know every detail about them or the inside of the earth, but in the future we will. Works Cited http://www.nmnh.si.edu/gvp/ The World Book Multimedia Encyclopedia (C) 1999 http://members.tripod.com/volcanoesk/