Volcanic rock - Wikipedia
WEBVolcanic rocks (often shortened to volcanics in scientific contexts) are rocks formed from lava erupted from a volcano. Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into hypabyssal and metamorphic rocks and constitute an important element of some sediments and sedimentary rocks.
Types of volcanic rock — Science Learning Hub
WEBNew Zealand has three main types of volcanoes, and each has been formed from a different type of magma. Once the lava has erupted, it cools and solidifies into rock: Basalt magma often forms shield volcanoes. Andesite magma often forms cone volcanoes. Rhyolite magma often forms calderas.
Igneous and Volcanic Rock Features - Geology.com
WEBVolcanic cones are steep-sided hills or mountains built of layers of erupted lava flows and fragments of volcanic rocks that have piled up around a central vent. As the name suggests, these features tend to be conical in shape and can be light- or dark-colored. There are three types of volcanic cones: 1) cinder cones, composite cones, and ...
Volcano facts and information - National Geographic
WEBJan 15, 2018 · Volcanoes, explained. These fiery peaks have belched up molten rock, hot ash, and gas since Earth formed billions of years ago. Volcanoes are Earth's geologic architects. They've created more than ...
Volcano | Definition, Types, & Facts | Britannica
WEBApr 23, 2024 · volcano, vent in the crust of Earth or another planet or satellite, from which issue eruptions of molten rock, hot rock fragments, and hot gases. A volcanic eruption is an awesome display of Earth’s power. Yet, while eruptions are spectacular to watch, they can cause disastrous loss of life and property, especially in densely populated ...
How volcanoes shaped our planet — and why we need to be
WEBApr 22, 2024 · Each rock tells a story. Mather describes human experiences of volcanic eruptions, including her own time spent staring into churning lakes of molten rock, a “roiling, red and restless” fiery sea.
About Volcanoes | U.S. Geological Survey - USGS.gov
WEBBy Volcano Hazards Program. Volcanoes are openings, or vents where lava, tephra (small rocks), and steam erupt onto the Earth's surface. Volcanic eruptions can last days, months, or even years.
Volcanoes - National Geographic Society
WEBOct 19, 2023 · A volcano is an opening in a planet or moon’s crust through which molten rock, hot gases, and other materials erupt. Volcanoes often form a hill or mountain as layers of rock and ash build up from repeated eruptions. Volcanoes are classified as active, dormant, or extinct.
Igneous Rocks - National Geographic Society
WEBOct 19, 2023 · When lava comes out of a volcano and solidifies into extrusive igneous rock, also called volcanic, the rock cools very quickly. Crystals inside solid volcanic rocks are small because they do not have much time to form until the rock cools all the way, which stops the crystal growth.
Lava | Types, Composition, Temperature, & Facts | Britannica
WEBApr 29, 2024 · lava, magma (molten rock) emerging as a liquid onto Earth’s surface. The term lava is also used for the solidified rock formed by the cooling of a molten lava flow. The temperatures of molten lava range from about 700 to 1,200 °C (1,300 to 2,200 °F).
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