Apetrographic province is ageological region within which theigneous rocks reveal a relationship (so-called consanguinity) inchemical composition, which may be referred to a community of origin. This relationship may be chemically a close one, but the rocks have widely varyingmineralogical composition, or the kinship may be restricted to one or more of the chemical components in the rocks.
Petrography derives frompetra (Greek:πέτρα), meaning 'rock', andgraphein (Greek:γράφειν), 'to write'.