Aregional, social, or ethnic variation of a language is known as a(n)

Dialect

A dialect is defined as the social, ethnic or a regional variation in a language that is different from the standard use in terms of idiom, pronunciation and in vocabulary.

It is most often applied to local or regional speech patterns. A dialect which is associated with the particular ethnic group is called as ethnolect and the regional is termed as regiolect.

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

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