View
234
Download
2
Tags:
Embed Size (px)
Citation preview
Rocks
The Geologic Dictionary
Rock Cycle
Magma
Igneous Rocks
Sedimentary Rocks
Metamorphic Rocks
Sediment
Crystallization Melting
Metamorphism
Lithification
Weathering
Erosion
Transport
Deposition
Metamorphic Rocks
Rocks Under Stress
Metamorphism
• Recrystalization• Solid-State Chemical
Reactions• No Melting
• Parent Rock Composition
• Temperature• Pressure• Fluids
Factors that affect Metamorphism
• Parent Rock Composition
• Temperature• Pressure• Fluids
Factors that affect Metamorphism
• Parent Rock Composition
• Temperature• Pressure• Fluids
Factors that affect Metamorphism
Lithostaticpressure
DirectionalPressure
Directed Pressure Results in:
Foliation
Foliation Under a Microscope
Metamorphic Grade
• Parent Rock Composition
• Temperature• Pressure• Fluids
Factors that affect Metamorphism
Metamorphic Rocks - Identification
Rock Identification is based on:
• Composition
What minerals make up the rock?
• Texture
What is the shape, size and orientation of the mineral grains that make up the rock?
Metamorphic Textures(All Crystalline)
Foliated
Nonfoliated
Foliation
Composition - Index Minerals
Composition - Index Minerals
Mineral Composition - Geothermometers
Rock Forms:500-550°C
Staurolite - Forms 500-750°C
Garnet - Forms 450-700°C
Muscovite - Forms 300-550°C
Foliated Metamorphic Rocks
Parent Rock - Shale
Slate (Low Grade)
Schist (Medium Grade)
Foliated Rocks (cont.)
Felsic Parent Rock
Gneiss (High Grade)
Migmatite (Very High Grade)
NonFoliated Rocks
Parent RockLimestone
Marble(Low to High Grade)
Nonfoliated Rocks (cont.)
Quartzite
Metacoglomerate
Parent Rocks
Sandstone
Conglomerate
Metamorphic Rocks - Interpretation
Metamorphic Environments=
Metamorphic Facies
Metamorphic Rock “Translations”
• Chemical Composition
• Mineral Composition
• Foliation
• Parent Rock (Protolith)
• T & P of Formation(Depth / Facies)
• T & P of Formation (Depth / Facies)