This preview shows page 1. Sign up to view the full content.
Unformatted text preview: c. Foliation
Minerals Recrystallize Perpendicular to the Directed Pressure
If the minerals are flat, such as sheetlike Micas, their parallel orientation gives a layered look; layering unrelated to the original bedding in the parent rock. Main factors affecting metamorphism
3. Parent rock Metamorphic rocks typically have the
same chemical composition as the rock
they were formed from.
they Different minerals, but made of the same
atoms. Exception: when hot water is involved. Metamorphic Settings Three types of metamorphic settings: 1. Contact metamorphism – due heat from adjacent rocks 2. Hydrothermal metamorphism – chemical alterations
from hot, ion-rich water
from 3. Regional metamorphism -- Occurs in the cores of
mountain belts and subduction zones (Converging
Margins) . Makes great volumes of metamorphic rock.
– a. Burial Metamorphism – e.g. Burial of sediments
deeper than 10 km – non-foliated
– b. Dynamothermal Metamorphism – Directed pressure
in Plate Tectonic Processes - foliated
in Most is Dynamothermal 1. Contact Metamorphism
Baking due to nearby Magma
Effect strongest in rocks in immediate contact Contact metamorphism
Produced mostly by local heat source Contact Metamorphism
Aureole 2. Hydrothermal Metamorphism
Due circulation of water near Magma
Important at midocean ridge Hydrothermal Metamorphism 3. Regional Metamorhism
3. Regional Metamorhism Most Dynamothermal metamorphism
Most Dynamothermal occurs along convergent plate boundaries
Example 1: Continent-Continent Collisions Compressional stresses deforms plate edge Continents Collide Major Folded Mountain Belts: Alps...
View Full Document
This document was uploaded on 01/26/2014.
- Winter '14