Forelesninger holdt ved Advanced Study Institute of Feldspar - Oslo 1962
Lectures held at Advanced Study Institute of Feldspar - Oslo 1962

For the purpose of this paper we shall define a metasomatic process as any process that results in a change in the bulk chemical composition of a mineral assemblage (rock) below the zone of weathering and sedimentation. Metasomatism can then be regarded as a matter of scale; that is, how much rock we include within the system we are consiclering. Metasomatism on the scale of a single thin section will not necessarily be metasomatism on the scale of a hand specimen and metasomatism of any rock unit will no longer be metasomatism when a sufficiently large volume of the earth is included in the system.