Earth Science: Exogenic & Endogenic Processes Overview for Students

Exogenic processes

Processes on Earth's surface caused by external forces (weathering, mass wasting, erosion).

Weathering

Mechanical and chemical breakdown of rocks into sediments.

Types of weathering

Physical, Chemical, Biotic.

Agents of physical weathering

Temperature, Frost action, Abrasion.

Block disintegration

Rocks break from repeated heating and cooling.

Exfoliation

Stripping off rock layers due to intense heating.

Frost action

Freezing and thawing of water in rock cracks causing breakage.

Abrasion

Rock surfaces scraped by friction with moving particles.

Main agents of chemical weathering

Oxygen (oxidation), Carbon dioxide (carbonation), Sulfur oxides (sulfuric acid), Water (hydration).

Biotic weathering

Weathering caused by plants, animals, and humans.

Mass wasting

Downslope movement of rock/soil due to gravity.

Types of slow mass wasting

Creep, Solifluction.

Types of fast mass wasting

Fall, Landslide (rockslide, slump, flow, mudflow).

Erosion

Wearing away and transport of soil/rock by natural forces.

Types of soil erosion

Wind, Sheet, Rill, Gully erosion.

Endogenic processes

Processes inside the Earth (magmatism, volcanism, plutonism, metamorphism).

Main heat sources of Earth's interior

Heat from Earth's formation, radioactive decay of isotopes.

Estimated Earth's core temperature

~6000°C.

How is Earth's heat redistributed

Conduction, convection, radiation.

Magmatism

Formation of magma beneath Earth's surface.

Ways magma forms

Decompression melting, Heat transfer.

Where does magma form

Mid-ocean ridges, Mantle plumes (hotspots), Subduction zones.

Volcanism

Eruption of magma, gases, and fluids through vents (mostly at plate boundaries).

Plutonism

Formation of intrusive igneous rocks (plutons) beneath Earth's crust.

Metamorphism

Change in rock composition/texture due to high temperature and pressure.

Types of metamorphism

Contact (near magma intrusions), Regional (large-scale, high-grade).

Common metamorphic processes

Recrystallization (new crystal structures), Neometamorphism (new minerals).