Geology Basics

Study Notes

Igneous Rocks

Formed from the cooling and solidification of magma or lava
Can be either intrusive (plutonic) or extrusive (volcanic)
Characteristics:
- Coarse-grained texture in intrusive rocks
- Fine-grained texture in extrusive rocks
- May contain gas bubbles or mineral crystals
Examples: granite, basalt, obsidian

Metamorphic Rocks

Formed through the alteration of existing rocks under high pressure and temperature
Process involves mineral recrystallization and changes in texture and composition
Characteristics:
- Foliated texture in rocks that have been subjected to differential stress
- Non-foliated texture in rocks that have not been subjected to differential stress
- May exhibit mineral banding or layering
Examples: marble, slate, quartzite

Sedimentary Rocks

Formed through the accumulation and compression of mineral and organic particles
Can be classified into three types:
1. Clastic sedimentary rocks: formed from the cementation of clastic sediments (e.g. sandstone, conglomerate)
2. Chemical sedimentary rocks: formed through chemical precipitation (e.g. rock salt, gypsum)
3. Organic sedimentary rocks: formed from the accumulation of organic matter (e.g. coal, limestone)
Characteristics:
- May exhibit bedding planes or cross-bedding
- Can contain fossils or other sedimentary structures

Mineral Identification

Minerals can be identified through a combination of physical and chemical properties
Key properties:
- Color and streak
- Luster and transparency
- Hardness and cleavage
- Density and specific gravity
- Crystal form and habit
Techniques:
- Hand lens examination
- Streak plate analysis
- Acid testing
- X-ray fluorescence (XRF) or X-ray diffraction (XRD) analysis

Geological Processes

Plate tectonics: the movement of the Earth's lithosphere and the resulting geological activity
Weathering and erosion: the breakdown and transportation of rocks and sediments
Diagenesis: the conversion of sediment into sedimentary rock
Metamorphism: the alteration of rocks under high pressure and temperature
Magmatic activity: the formation and movement of magma and lava

Description

Test your knowledge of geology fundamentals, including types of rocks, mineral identification, and geological processes. From igneous to sedimentary rocks, and from plate tectonics to diagenesis, this quiz covers the basics of geology.