What is metasomatism and explain?
Answers
Metasomatism (from the Greek μετά (change) and σῶμα (body)) is the chemical alteration of a rock by hydrothermal and other fluids. [1] It is the replacement of one rock by another of different mineralogical and chemical composition. ... Synonyms to the word metasomatism are metasomatose and metasomatic process
Metasomatism is a metamorphic process by which the chemical composition of a rock or rock portion is altered this involves the introduction and/or removal of chemical components as a result of the interaction of the rock with aqueous fluids (solutions). During metasomatism the rock remains in a solid state. Metasomatic rocks, in general, have a granofelsic or granoblastic structure. They may be coarse- or fine-grained and may sometimes exhibit banding which may be rhythmic. They may demonstrably overprint earlier structures.
There are 2 types of Metasomatism :
1. Diffusional Metasomatism – which takes place by the diffusion of a solute through a stagnant solution (fluid). The driving force of diffusion is the chemical potential (or chemical activity) gradients in the rock-pore solution.
2. Infiltrational Metasomatism – which takes place by the transfer of material in solution, infiltrating through the host rocks. The driving force is the pressure and concentration gradients between the infiltrating and rock-pore solutions.