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Volcanoes. Cinder Cone Volcano Shield Volcano Composite Volcano. Cinder Cones. A type of volcano made of many layers of broken rocks and ash. Wizard Island found in Crater Lake and Lava Butte in Oregon are examples. Simplest type of volcano.
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Volcanoes • Cinder Cone Volcano • Shield Volcano • Composite Volcano
Cinder Cones A type of volcano made of many layers of broken rocks and ash. Wizard Island found in Crater Lake and Lava Butte in Oregon are examples.
Simplest type of volcano. • Built from particles and blobs of congealed lava ejected from a single vent • Breaks into small fragments that solidify and fall as cinders around the vent to form a circular or oval cone • Cinder cones are numerous in western North America
Shield Volcanoes This volcano is made from many layers of lava. This lava was very fluid when it flowed out of the volcano. These volcanoes have very large bases. Most Hawaiian volcanoes are this type.
Built almost entirely of fluid lava flows. • Profile much like that of a warrior's shield. • Lava pours out in all directions from a central summit vent, or group of vents, building a broad, gently sloping cone of flat, domical shape. • Some of the largest volcanoes in the world are shield volcanoes.
Composite Volcanoes This volcano is made of alternating layers of ash and lava. They are very explosive volcanoes. Mt. St. Helens and Mt. Rainier is this type.
Some of the Earth's grandest mountains are composite volcanoes--sometimes called stratovolcanoes. • Typically steep-sided, symmetrical cones of large dimension built of alternating layers of lava flows, volcanic ash, cinders, blocks. • Mount Fuji in Japan, Mount Hood in Oregon, and Mount St. Helens and Mount Rainier in Washington. • Most composite volcanoes have a crater at the summit which contains a central vent or a clustered group of vents. • Lavas either flow through breaks in the crater wall or issue from fissures on the flanks of the cone.
Crater Lake is a caldera, the remains of an ancient Pleistocene volcano named Mt. Mazama. The caldera was formed when Mt. Mazama violently erupted some 7600 years ago, causing the entire top of the mountain to fall in on its self. Once it collapsed and sealed, snow melt and rain filled the caldera, and formed what we know now as Crater Lake.
Earthquake: A sudden violent movement of the earth's crust caused by the release of stress faults or by volcanic activity.