Types of Metamorphism in brief ideas to understand

Types of Metamorphism is

1. Types of Metamorphism

2. INTRODUCTION There are several approaches to classifying metamorphic processes, and geologists also disagree on the categories pertaining to any single approach. One approach is to classify metamorphism on the basis of the principal agent or process involved. Thermal metamorphism results when heat transfer is the dominant agent (such as near plutons). Dynamic Metamorphism occurs when Deviatoric stress results in deformation and recrystallization . Dynamo-thermal metamorphism results when temperature and stresses are combined, as in orogenic belts. Metasomatism because fluid-enhanced infiltration and alteration is a process distinct from the above three.

3. IUGS/SCMR RECOMMENDED CLASSIFICATION A)Contact Metamorphism 1) Pyrometamorphism B) Regional Metamorphism 1)Orogenic Metamorphism

2) Burial Metamorphism

3) Ocean Floor Metamorphism C) Hydrothermal Metamorphism
D) Fault-Zone Metamorphism
E) Impact or Shock Metamorphis m The IUGS/SCMR recommendations also include Hot-slab, Combustion, and Lightning Metamorphism, all of which occur in rare and localized occurrences (Fettes and Desmons , 2007).

4. CONTACT METAMORPHISM It is a metamorphism of local extent. Intrusion of magma bodies into host/country rocks. Contact aureole is the zone where effect of Contact Metamorphism is seen. Width may range from several metres to few kilometres. A common metamorphic rock is Hornfels (Hard Rock). This is also known as Thermal Metamorphism. Most obvious of their effect is seen in contact of Sedimentary bodies with Igneous intrusions. Rocks exhibiting them are fine grained and lack schistosity . Eg : Marble, Quartzite, Hornfels