Deep underground, zones of metamorphism form around the hot
magma of batholiths. Rocks that are in contact with hot magma or
lava often become metamorphosed. This is called contact
metamorphism. Contact metamorphism can either happen deep
underground or at the Earth's surface. Underground, hot magma,
fills areas within the crust; large areas are called batholiths.
The hot magma alters the surrounding rocks. The amount of rock
that is changed depends on how much magma there is producing
heat. The zone of altered rock around a batholith is called an
aureole and it may cover more than 100 square kilometers of
land. Above ground, lava erupting from a volcano alters the rock
that it erupts onto. Metamorphism of rocks that happens over
larger areas is called regional metamorphism. Shop Windows to
the Universe Science Store! The Fall 2010 issue of The Earth
Scientist , focuses on rocks and minerals, including articles on
minerals and mining, the use of minerals in society, and rare
earth minerals, and includes 3 pos