Geology: Minerals and the Rock Cycle

Study Notes

Minerals

Naturally occurring, inorganic solids with a definite chemical composition and crystalline structure.
Examples: Quartz, feldspar, and mica.

Magma and Lava

Magma: Molten rock found beneath the Earth's surface.
Contains a mixture of liquid rock, crystals, and dissolved gases.
Lava: Magma that has reached the Earth's surface through volcanic eruptions.
Lava forms igneous rock when it cools and solidifies.

The Rock Cycle

Continuous process of transforming rocks from one type to another.
Involves formation, breakdown, and reformation of rocks through processes like cooling, erosion, sedimentation, and metamorphism.

Formation of Igneous Rocks

Formed from the solidification of magma or lava.
Intrusive igneous rocks: Formed from magma cooling slowly beneath the Earth's surface (thousands to million of years).
Extrusive igneous rocks: Formed from lava cooling quickly on the surface (days to weeks).

Intrusive vs. Extrusive Igneous Rocks

Intrusive: Larger crystals due to slow cooling (examples: granite and diorite).
Extrusive: Smaller crystals or may be glassy due to rapid cooling (examples: basalt and pumice).

Formation of Sedimentary Rocks

Formed through the accumulation and compaction of sediment (fragments of other rocks, minerals, and organic material).
Process can take thousands to millions of years depending on environment and conditions.
Examples: Sandstone, limestone, and shale.

Formation of Metamorphic Rocks

Formed from existing rocks (igneous, sedimentary, or other metamorphic rocks) undergoing changes due to high temperature, high pressure, or chemically active fluids.
Metamorphosis can take thousands to millions of years.
Examples: Schist, gneiss, and marble.

Classifying Rocks

Metamorphic Rocks: Formed from alteration of existing rocks, often have a foliated or banded appearance, and can contain larger crystals due to recrystallization (e.g., schist, gneiss).
Igneous Rocks: Formed from solidification of molten rock, crystal size varies depending on cooling rate (e.g., granite - intrusive, basalt - extrusive).
Sedimentary Rocks: Formed from accumulation of sediment, often have a layered appearance, may contain fossils and have varying grain sizes (e.g., sandstone, limestone).

Weathering, Erosion, and Deposition

Weathering: Breaking down rocks into smaller pieces through physical, chemical, or biological means.
Erosion: Removal and transportation of weathered material from one location to another, often by wind, water, or ice.
Deposition: Eroded material is deposited in a new location, leading to the formation of new geological features.

Ore

Naturally occurring solid material from which a metal or valuable mineral can be extracted profitably
Examples: Iron ore, copper ore, gold ore.

Types of Mineral Separation

Filtration: Separating solids from liquids by passing the mixture through a filter.

Description

This quiz explores the fundamentals of minerals, magma, and the rock cycle. You'll learn about igneous rock formation and the differences between intrusive and extrusive rocks. Test your knowledge and deepen your understanding of geological processes.