Earth’s Structure, Rocks, and Magma: A Concise Overview
Earth’s Structure and Composition
Dynamic: Lithosphere-Asthenosphere-Mesosphere – endosphere
Mechanical: Lithosphere, Asthenosphere, Mesosphere, Outer Core, Inner Core
Plate Tectonics: The continents were once united.
Seismic Reconnaissance
P-waves: Longitudinal and transverse. Travel through the core, but S-waves do not.
P-waves: Pierce liquids, S-waves do not.
Earth’s Layers
Endosphere: The two cores.
Edges of lithospheric plates: Constructive, Destructive, Transform
Plate Boundaries
Divergent: One plate subducts under another.
Silicate Minerals
Amphibole: Inosilicates. Micas: Phyllosilicates
Folds
TPOs of anticline and syncline folds
Magma Evolution
Evolution of magma: Differentiation, Assimilation, and Mixing
Types of Magma
Types of Magma: Molten basalt, granite, and alkaline magma
Isosilicates
Isosilicates: (SiO4)-4, tetrahedral structure and polymerization
Nesosilicates
Nesosilicates: Isolated tetrahedra (Olivine)
Inosilicates
Inosilicates: Tetrahedra in a row
- Simple: Pyroxene
- Double: Amphiboles
Phyllosilicates
Phyllosilicates: Tetrahedra in sheets
- Micas: Muscovite, Biotite
- Clay minerals: Kaolinite, Illite, Montmorillonite
Sedimentary Deposits
Debris: Chemical and organic chemical compounds from precipitation or accumulation of remains of living organisms.
Dynamometamorphism
Dynamometamorphism: Grinding, pulverizing of the rock.
Rock Types
Igneous Rocks
R: Slow cooling = Coarse grain.
Sedimentary Rocks
Sedimentary Rocks: Materials deposited to form layers or strata. Pieces of other rocks.
Igneous Rocks Formation
Igneous Rocks: Cooling of molten rock (magma).
Magma cools either on Earth’s surface by volcanic activity or inside the Earth, forming plutonic rocks. Crystallization in bark crevices forms filonian igneous rocks.
Igneous Rock Examples
Igneous Rocks:
- Plutonic: Granite, Diorite, Peridotite, Gabbro
- Volcanic: Lava, Pyroclastic deposits, Pumice, Rhyolite, Andesite, Ballasts
Filonian Igneous Rocks
Filonian Igneous Rocks: Crystallized in bark crevices.
Igneous Silicates
Igneous Silicates: Solidification of magma. Porphyritic texture.
Intrusive Igneous Rocks
Intrusive Igneous Rocks: Granites
Extrusive Igneous Rocks
Extrusive Igneous Rocks: Basalts
Metamorphic Rocks
Metamorphic Rocks: Formed from other rocks under pressure and high temperatures. (Slate, Schist)
Metamorphic Rocks: Formed from other rocks under great pressures and temperatures.
Volcanic Rocks
Volcanic Rocks: Rapid Cooling = Fine Grain.
Metamorphism
Metamorphism: Change of state of minerals due to pressure and temperature.
Metamorphic effects: Texture, structure, and mineral composition.
Contact Metamorphism
Contact Metamorphism: Occurs around magma intrusions.
Rock Transformations
Argillite to shale, limonite
Mineral Properties
Mineral properties: Color, Weight, Luster
Magmatic Differentiation
Magmatic Differentiation: Physical-chemical separation of magmas.
Calcite Formation
Calcites: Chemical precipitation and accumulation of skeletons.
Diagenesis
Sediment to sedimentary rock diagenesis. Sedimentary mineral halite
Lithification
Lithification: Sediment becomes rock.
Basalt
Basalt: Volcanic rock of Earth’s crust.
Plate Tectonics and Lithosphere
Divergent: Creates lithosphere. Convergent: Destroys lithosphere.
Regional Metamorphism
Regional metamorphism: Kilometers deep and at high altitudes.
Tectosilicates
Tectosilicates: Tetrahedra in three-dimensional networks
- Feldspars: Orthoclase, Albite, Anorthite
Plagioclase
Plagioclase: Solid solution of Albite – Anorthite. Quartz: Silicon and oxygen at 100%
Igneous Dams
Igneous Dam: Carries Quartz
Hydrothermal Deposits
Hydrothermal deposits: Exit fracture with waste water.
Basaltic Magma
Basaltic magma: Upper mantle
Obsidian
Obsidian: Rapid magma cooling