Introduction to Geology

Geology

Definition and Scope

• Geology is the scientific study of the Earth's physical structure, composition, and processes
• Encompasses the study of rocks, minerals, landforms, and natural phenomena such as earthquakes and volcanoes

Branches of Geology

• Petrology: study of rocks and their composition
• Mineralogy: study of minerals and their properties
• Structural Geology: study of the three-dimensional distribution of rocks and their relationships
• Geomorphology: study of the shape and features of the Earth's surface
• Geophysics: study of the Earth's internal and external physical processes
• Geochemistry: study of the chemical composition of the Earth and its processes

Rock Types

• Igneous: formed from molten magma or lava
  • Intrusive: forms below the Earth's surface
  • Extrusive: forms above the Earth's surface
• Sedimentary: formed from compressed and cemented sediments
• Metamorphic: formed from altered existing rocks under high pressure and temperature

Geological Processes

• Plate Tectonics: movement of the Earth's lithosphere (outer layer) leading to the creation of mountains, volcanoes, and earthquakes
• Weathering: breakdown of rocks into smaller particles
• Erosion: removal of rocks and soil through natural forces such as wind and water
• Deposition: settling of sediments and rocks in a new location

Geological Time Scale

• Eons: largest unit of time, divided into:
  • Phanerozoic: visible life present
  • Proterozoic: complex life present
  • Archean: early life present
  • Hadean: primordial Earth
• Eras: subdivisions of eons, divided into:
  • Periods: further subdivisions of eras
  • Epochs: smallest unit of time, used to date specific events

Geology

Definition and Scope

• Scientific study of the Earth's physical structure, composition, and processes
• Includes the study of rocks, minerals, landforms, and natural phenomena like earthquakes and volcanoes

Branches of Geology

Petrology

• Study of rocks and their composition

Mineralogy

• Study of minerals and their properties

Structural Geology

• Study of the three-dimensional distribution of rocks and their relationships

Geomorphology

• Study of the shape and features of the Earth's surface

Geophysics

• Study of the Earth's internal and external physical processes

Geochemistry

• Study of the chemical composition of the Earth and its processes

Rock Types

Igneous Rocks

• Formed from molten magma or lava
• Divided into:
  • Intrusive: forms below the Earth's surface
  • Extrusive: forms above the Earth's surface

Sedimentary Rocks

• Formed from compressed and cemented sediments

Metamorphic Rocks

• Formed from altered existing rocks under high pressure and temperature

Geological Processes

Plate Tectonics

• Movement of the Earth's lithosphere leading to the creation of mountains, volcanoes, and earthquakes

Weathering

• Breakdown of rocks into smaller particles

Erosion

• Removal of rocks and soil through natural forces like wind and water

Deposition

• Settling of sediments and rocks in a new location

Geological Time Scale

Eons

• Largest unit of time, divided into:
  • Phanerozoic: visible life present
  • Proterozoic: complex life present
  • Archean: early life present
  • Hadean: primordial Earth

Eras

• Subdivisions of eons, divided into:
  • Periods: further subdivisions of eras
  • Epochs: smallest unit of time, used to date specific events

Learn about the scientific study of the Earth's physical structure, composition, and processes. Explore branches of geology including petrology, mineralogy, and structural geology.