igneous rock

Table of Contents

Introduction
Composition
- Chemical components
- Mineralogical components
Textural features
- Crystallinity
- Granularity
  - Grain size
  - Fabric
  - Important textural types
Structural features
- Small-scale structural features
- Large-scale structural features
  - Clastic structures
  - Flow structures
  - Fractures
  - Inclusions
  - Pillow structures
  - Segregations
  - Zonal structures
Classification of igneous rocks
- Classification of plutonic rocks
- Classification of volcanic and hypabyssal rocks
Origin and distribution
- Origin of magmas
- Nature of magmas
- Crystallization from magmas
  - The forsterite-cristobalite system
  - The albite-anorthite system
  - Bowen’s reaction series
  - Assimilation
- Volatile constituents and late magmatic processes
  - Effects of water and other volatiles
  - Pegmatites and late-stage mineralization
Forms of occurrence
- Extrusive igneous rocks
- Intrusive igneous rocks
- Distribution of igneous rocks on Earth’s surface
  - Divergent plate boundaries
  - Convergent plate boundaries
  - Flood basalts
  - Other terrestrial occurrences
  - Extraterrestrial occurrences

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temperature of Earth

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intrusive igneous rock

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rock textural terms

igneous rock: pumice and obsidian

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Topics

felsic and mafic rocks pegmatite spherulite dike micropegmatite colour index sill alkaline rock laccolith crystallite sedimentary rock metamorphic rock cryoseism stratification regolith exfoliation bedrock aquifer bulging crystalline rock

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Key People

Norman L. Bowen

Canadian petrologist

Nicolas Desmarest

French geologist

Johan Vogt

Johan Herman Lie Vogt

Norwegian geologist

Joseph Paxson Iddings

American geologist

Brøgger, Waldemar Christofer

Waldemar Christofer Brøgger

Norwegian geologist

Louis Valentine Pirsson

American geologist

Arie Poldervaart

American geologist and petrologist

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