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 Metamorphism
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