A Volcano is an opening in the Earth's surface or crust,
which allows hot, molten rock, ash and gases to escape from
deep below the surface. Volcanic activity involving the extrusion of rock tends
to form mountains or features like mountains over a period of time.
The most common perception of a volcano is of a conical mountain, spewing lava
and poisonous gases from a crater in its top. This describes just one of many
types of volcano and the features of volcanoes are much more complicated. The
structure and behaviour of volcanoes depends on a number of factors. Some
volcanoes have rugged peaks formed by lava domes rather than a summit crater,
whereas others present landscape features such as massive plateaus.
The animation on this page schematically illustrates the eruption mechanism of
a generic volcano. Rocks from the lowermantle melt and become liquid
rocks, or magma and, rising the denser rock layers toward
Earth's surface, it gathers in a huge pool, called a magma chamber.
High pressure, in a magma chamber, pushes the magma towards the above through
the conduit or weak spots in the crust and the magma reaches the surface: so
there is an eruption! The volcano erupt different types of products and,
however, there are different types of volcanoes associated to
different eruption styles.
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