Lava
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Lava moves across the ground as a pahoehoe flow, Kilauea Volcano, Hawai`i
Lava is the term for magma from the Earth's mantle when it erupts onto the Earth's surface. Geologists also use the word to describe the solidified deposits of lava flows and fragments hurled into the air by explosive eruptions (for example, lava bombs or blocks). Lavas differ in chemical composition, but most forms of lava average 3000-4000 degrees Fahrenheit. Lavas are classified into the following categories based on their chemical composition: Basalt (Hawaiian volcanoes), Andesite (Andes Mountains), Dacite (Mt. St. Helens), or Rhyolite (Yellowstone Caldera).