Volcanic Rock
Volcano Terms and Definition


Fire Mountain: The Eruption and Rebirth of Mount St. Helens
Two hundred and thirty square miles leveled in moments Five hundred and forty million tons of ash and volcanic rock exploded twelve miles high One cubic mile of earth blasted from the crest of one of the world's most beautiful snowcapped domes Captured in rare and spectacular aerial photography and survivor's own words and pictures, witness the terrifying fury of the worst volcanic disaster in American history
Rock

Rocks are naturally occurring mixtures of minerals, mineral matter, or organic materials. Three main types occur: sedimentary rocks, formed by weathering and mechanical sorting on the Earth's surface; metamorphic rocks, which are rocks that have been transformed by the effects of high temperature and pressure; and igneous rocks, derived from magma (for example, volcanic rocks ).


  • Common sedimentary rocks include sandstone, limestone, and shale. These rocks often start as sediments carried in rivers and deposited in lakes and oceans. When buried, the sediments lose water and become cemented to form rock.
  • Common metamorphic rocks include schist, marble, and gneiss. The sedimentary rock shale (formed mostly of clay sediments) when buried and heated to high temperatures (300-500°C) becomes transformed or metamorphosed into schist.
  • Common volcanic (igneous rocks) are basalt, andesite, and rhyolite. When magmas crystallize deep underground they look different from volcanic rocks because they cool more slowly and, therefore, have larger crystals. Igneous rocks cooled beneath the Earth's surface are called intrusive rocks. The intrusive equivalents of basalt, andesite, and rhyolite are gabbro, diorite, and granite, respectively.


Lava Flows and Lava Tubes
40-minute video uses spectacular and unusual footage of erupting volcanoes from Hawaii and around the world to explain the features found in many of our volcanic national parks and monuments, and to show how they form. It presents up-to-date scientific ideas about lava flows: how they move, how they change, and how they create lava tubes

Volcano Glossary



NOVA - In the Path of a Killer Volcano
The scientists who remain behind- and see some astonishing footage of the world's largest volcanic eruption in 80 years. Local tribes people were the first to see the signs. "There was a flash of light from the sky"

National Geographic - Volcano
The most dazzling but destructive natural force on earth. Massive volcanic eruption can turn day into night, releasing the power of an atomic blast, spewing toxic avalanches of lava, gas, and ash. National Geographic Video transports you to some of the world's most notorious volcanoes

National Geographic's Restless Earth Collection
Asteroids Deadly Impact Volcano Nature's Fury. The devastating powers of earthquakes, hurricanes, tornadoes, volcanoes and other earth-shattering forces of nature in dramatic scenes of destruction and inspiring human courage captured by the acclaimed filmmakers of National Geographic

Super volcano - It's Under Yellowstone. And It's Overdue

A subterranean sea of molten lava that scientists are sure will burst through the Earth's crust it's just a question of when. And if the resulting super-volcanic eruption is anything like the last one on earth which plunged the world into darkness for six years, tipped us into the last Ice Age and reduced the human population to just 2,000 people we're in for one explosive ride


Baby Einstein Play Gyms
Let the Baby Einstein Seek and Discover Activity Gyms stimulate and inspire your baby. The soft mat provides a comfortable place for baby to rest, while bright colors, fun characters and a variety of toys provide an enriched environment for baby to explore.

Young Learners Microscopes
Expose your child to the fascinating world of natural specimens as you examine an arachnid, a crustacean and other insects up-close. Grades K & up. Fully functioning microscope makes learning fun!

Elenco Electronics
Electronic Snap Circuits by Elenco is an award-winning toy for budding engineers eight years old and above. For students who are already learning about electronics in school, this set creates a hands-on experience that makes for more fun than reading about how these things work in a textbook.



Source:
U.S. Department of the Interior