WJEC A LEVEL GEOLOGY
EXTENSION UNIT 1 : ROCK FORMING PROCESSES
METAMORPHIC PROCESSES AND PRODUCTS
1
Metamorphism
Define:
a) Contact Metamorphism.
b) 'Buchan type' Regional Metamorphism
c) Burial Regional Metamorphism.
d) Dynamic Metamorphism.
2
Factors controlling metamorphism
What factors control the type and degree of metamorphism?
3
Stability Fields
Copy; Igneous and sedimentary rocks contain minerals that are stable or
metastable at the temperature of their formation. Changes in temperature
and/or
pressure during metamorphism lead to the growth of new minerals with
different
stability fields.
Why are sedimentary rocks more susceptible to metamorphism than igneous
rocks?
4
The relationship between temperature, pressure type of metamorphism.
Copy and describe graph 17.14 P+S
5
2.13
Copy the phase diagram showing the stability fields of aluminium silicates fig
p18 McLeish.
6
Metamorphic Facies
Define Metamorphic Facies.
Copy and describe fig 7.5 McLeish; refer to the previous graph and different
metamorphic environments.
7
Copy the table fig 7.2 p146 McLeish.
8
Contact metamorphism of Mudstone
Complete the table below to describe i) the mineralogical changes ii) the
textural
changes that occur during contact metamorphism of mudstone at
a)low b)medium c)high grade.
Rock type +
Metamorphic
Grade
Mineralogical
changes
Textural change
Diagram
Spotted Rock
Low Grade
Andalusite
Hornfels
Medium Grade
Hornfels
High Grade
9
Explain, using examples, how Index Minerals can be used to determine the
grade of contact metamorphism.
10
Regional metamorphism of Mudstone
Complete the table below to describe i) the mineralogical changes ii) the
textural
changes that occur during regional metamorphism of mudstone at
a)low b)medium c)high grade.
Rock type +
Metamorphic
Grade
Mineralogical
changes
Textural change
Diagram
Slate
Low Grade
Phyllite
Low Grade
Chlorite Schist
Medium Grade
Mica Schist
Medium Grade
Gneiss
High Grade
11
Explain, using examples, how Index Minerals can be used to determine the
metamorphic grade of regionally metamorphosed rocks (include Buchan and
Barrovian zoning).
12
Explain the mineralogical changes that occur during metamorphism of basic
igneous rocks.
13
Explain the mineralogical changes that occur during metamorphism of pure and
impure limestones.
14
Using examples, explain the processes of:
a) Metasomatism (nb Limestones)
b) Pneumatolysis (nb Tourmalinisation)
15
Metamorphic textures
Using diagrams, explain the origin of the following:
i)
Granular texture of Metaquartzite.
ii)
Slaty Cleavage
iii)
Mylonite
iv)
Migmatite
ESTA GEOTREX The Geology Teachers Resource Exchange
Contributor: Ben Church Establishment: Monmouth Comprehensive School Date:24:05:05