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