Extrusive igneous rocks form when magma reaches the Earth's surface a volcano and cools quickly. Most extrusive (volcanic) rocks have small crystals. Examples include basalt, rhyolite, and andesite. Basalt Rhyolite Andesite

Volcano Cams

Take a peek at these active volcanoes! Ruapehu Volcano, New Zealand Popocatepetl, Mexico Mt. St. Helens, Washington

Volcano Cartoons from the Michigan Technological University Volcanoes Page Outland by Berkeley Breathed B.C. by Johnny Hart Marvin by Tom Armstrong Sketch by "elan" Differing views by S. Harris

Volcano Web Links Volcano World The Web's Premier Source of Volcano Info Volcanoes An on-line book about volcanoes from the U.S. Geological Survey Terrestrial Volcanoes View movies, satellite images, animations, and discover more about current and ancient volcanoes.

Igneous Rocks

Rock Cycle