Transcript Slide 1

Rock Cycle
http://www.uwgb.edu/dutchs/Earth
SC-202VisualsIndex.HTM
View From Space - Klyuchevskaya, Russia
Igneous Rocks Cool from the
Molten State
• Extrusive -- Erupted on Surface (volcanic)
• Intrusive -- Solidify Within Earth (Plutonic)
Large Grain Size ---> Slow Cooling
• Extrusive Rocks -- Fine Grained
• Intrusive Rocks -- Coarse Grained
Metamorphic Facies
Depth\Tem
p
300C
5 km
Zeolite Contact Metamorphism - Andalusite forms
10 km - 3
kb
Greenschist
Chlorite, Biotite
Bluesc form
•Slate
hist
•Greenstone
•Quartzite
•Marble
Amphibolite
Garnet,
Staurolite,
Kyanite form
•Schist
•Amphibolite
•Quartzite
•Marble
•Gneiss
Not Found
Eclogite (Mantle)
15 km
20 km - 6
kb
25 km
400C
30 km - 9
kb
500 C
600 C
700 C
Granulite
Sillimanite
forms
Muscovite
breaks down to
K-feldspar
Partial Melting
•Gneiss
35 km
40 km - 12
kb
800 C
Bowen's Series and Igneous
Rocks
Metamorphism
•Changes in Rock Composition or Texture
•Due to Heat, Pressure and Action of
Fluids (like magma)
Major Metamorphic Rock Types
Temp
C
Temp F
Coal
Limestone
Sandstone
Basalt
Shale
Index
Minerals
Slate
Chlorite
Phyllite
Biotite
Schist
Garnet
Lignite
Bituminous
300
500
Anthracite
600
Graphite
Marble
700
800
500
1100
1200
700
Quartzite
900
1000
600
Greenstone
Amphibolite
Staurolite
Gneiss
Kyanite
Sillimanit
e
Melting
Begins
Types of Metamorphism
Contact
• Around Intrusions
• Shallow: 0-6 Km
• Low Pressure
• Local
Regional
• Wide Areas
• 5-20 Km, Sometimes
30+
• High Pressure
• Usually Accompained
by Deformation
Sedimentary Rocks
Deposited on or Near Surface of Earth by
Mechanical or Chemical Processes
Environmental Clues in
Sedimentary Rocks
• Fossils
– Salt Water - Corals, Echinoderms
– Fresh Water - Insects, Amphibians
– Terrestrial - Leaves, Land Animals
• Color And Chemistry
– Red Beds - Often Terrestrial
– Black Shale - Oxygen Poor, Often Deep
Water
– Evaporites – Arid Climates
Sediment Sizes and Clastic
Rock Types
Rock Type
Sediment Grain Size
Shale
Clay
less than 0.001 mm
Siltstone
Silt
.001-0.1 mm
Sandstone
Sand
.01-1 mm
Conglomerate Gravel
1mm +
Sedimentary rocks made of silt- and claysized particles are collectively called
mudrocks, and are the most abundant
sedimentary rocks.
Facies Changes
Plant Fragments Are Often
Visible in Coal
Diagenesis
What Rocks Tell Us
Rock Type
Igneous
Sedimentary
How Classified
What it Tells Us
Composition
Texture
Chemical
Composition
Tectonic Setting
Cooling History
Surface
Environment
Energy of
Environment
Original Rock Type
Temperature,
Pressure
Degree of Change
Grain Size
Composition
Metamorphic
Mineral Makeup
Texture