The word extrusive means that the magma was forced onto the earth's surface and cooled in a matter of hours. Granite is an example of intrusive igneous rock.

Marble. Chalk. The Giant’s Causeway. All made of rock but all different. Learn all about the three different types of rock found on Earth with BBC Bitesize.

Igneous rocks close igneous rockIgneous rocks are those which have been formed by the cooling and solidification of molten rock (magma) from underneath the earth’s crust. are formed by magma ...

Igneous rocks are among the oldest types of rocks found on Earth. They form when hot, melted rock– known as magma (underground) or lava (on the surface) – cools and hardens.

Article citations More>> Le Maitre, R.W., Bateman, P., Dudek, A.J. and Keller, M.J. (1989) A Classification of Igneous Rocks and Glossary of Terms, Blackwell, Oxford, 193. has been cited by the ...

Article citations More>> Lu Muller, D. and Groves, D.I. (1997) Potassic Igneous Rocks and Associated Gold-copper Mineralization, Second Updated. Springer Vrelag, Berlin, 242 p. has been cited by the ...

The Quaternary Tarosero volcano is situated in the East African Rift of northern Tanzania and mainly consists of trachyte lavas and some trachytic tuffs. In addition, there are minor occurrences of ...