An extrusive rock is a rock that has been deposited at the earths surface as a liquid/fluid, coming to the surface form a depth through a fissure in the earth as a liquid/fluid. The most common type of liquid rock is a magma and magmas erupting at the surface are called "volcanoes" and thus the rocks are called "volcanic" rocks. However there are also volcanoes to be found that have nothing to do with molten rock magmas. These are called "Mud" volcanoes and they are caused by de-watering processes in rocks. The muds brought to the surface are also technically extrusive and these are NOT volcanic rocks.
The major process of surface rock formation on volcanoes is volcanic eruptions. When molten rock (magma) from the Earth's mantle reaches the surface, it solidifies to form igneous rocks like basalt or rhyolite. Over time, repeated eruptions build up layers of volcanic rocks that contribute to the formation of the volcano.
Volcanoes are typically associated with igneous rocks, which are formed from the solidification of magma or lava. Igneous rocks such as basalt and andesite are commonly found in and around volcanic areas.
Hot spot volcanoes are called mantle plumes. These volcanic features occur when molten rock rises from deep within the Earth's mantle, creating localized volcanic activity on the surface. Examples include the Hawaiian Islands and Yellowstone National Park.
The rocks that come out of volcanoes are called volcanic rocks. These rocks are formed from lava that has cooled and solidified either within the volcano or on the Earth's surface. Examples include basalt, andesite, and rhyolite.
Volcanic islands are formed by volcanoes and are therefore composed of volcanic rock.
There are many kinds of volcanic rock. http://en.wikipedia.org/wiki/Volcanic_rock
Yes. Pumice is a volcanic rock.
Granite is an igneous rock. It is not considered a volcanic rock, but a plutonic rock.
volcanic rock
Certain species of elephants have been known to climb to volcanoes and consume lumps of volcanic rock. This volcanic rock is rich in sodium, important for the elephants diet.
not all are made of volcanic rock but those that are close to active volcanoes will most prob be built of volcanic rock :-)
by undersea volcanoes by dried up volcanic rock
AAA is nothing in relation to volcanoes. A'a is a variety of volcanic rock, formed from a basaltic lava flow with a jagged surface.
Tobago is volcanic in origin, but there are no volcanoes on Trinidad or Tobago.Tobago is volcanic in origin, but there are no volcanoes on Trinidad or Tobago.Tobago is volcanic in origin, but there are no volcanoes on Trinidad or Tobago.Tobago is volcanic in origin, but there are no volcanoes on Trinidad or Tobago.Tobago is volcanic in origin, but there are no volcanoes on Trinidad or Tobago.Tobago is volcanic in origin, but there are no volcanoes on Trinidad or Tobago.Tobago is volcanic in origin, but there are no volcanoes on Trinidad or Tobago.Tobago is volcanic in origin, but there are no volcanoes on Trinidad or Tobago.Tobago is volcanic in origin, but there are no volcanoes on Trinidad or Tobago.Tobago is volcanic in origin, but there are no volcanoes on Trinidad or Tobago.Tobago is volcanic in origin, but there are no volcanoes on Trinidad or Tobago.
Virgina did have volcanoes in the ancient times. Scientists have found traces of volcanic rock in the ground.
Explosive volcanoes can produce pumice and tuff.