agents of metamorphism

1
Ch 8 Metamorphism

• agents of metamorphism
• foliation (lab)
• types of metamorphic rock and resources (lab)
• metamorphic environments
• metamorphic zones and index minerals
• shield

2

• Metamorphic Rock
• Heat
• Pressure
• Confining pressure
• Differential pressure
• Chemically Active Fluid

3

• Metamorphism changes rocks by
• Flattening crystals and lining them up in single
  direction
• Forcing crystals together reducing pore size
• Forming larger crystals of existing minerals
• Recombining elements into different minerals
  (note water and gasses may form and escape)

4

• Metamorphic environments
• contact metamorphism
• Aureole -zone
• Isograd - line

Produces index minerals AND marble and quartzite
5
2. Burial Metamorphism

• Increasing pressure
• Increasing temperature

6

• 3. Regional metamorphism
• Produces
• Foliated rocks
• Non-foliated rocks
• Index minerals

Ancient metamorphic rock of Canadian Shield,
Northwest Territories, Canada
7
4. Hydrothermal alteration
8
(No Transcript)
9
Shield Canadian Shield