Land Shaping processes

Tectonic uplift

The vertical raising of Earth’s crust due to plate collision or compression.

Subduction

When one tectonic plate moves beneath another, forming trenches and volcanic arcs.

Rifting

Crustal stretching that forms valleys and basins as plates pull apart.

Folding

Bending of rock layers under compressional forces.

Faulting

Breaking and displacement of Earth’s crust along a fracture line.

Isostatic rebound

Land rising after the removal of heavy ice or sediment weight.

Seafloor spreading

Formation of new oceanic crust as plates diverge at mid-ocean ridges.

Orogeny

Mountain-building through crustal compression and uplift.

Volcanism

Eruption of magma onto Earth’s surface forming cones, domes, or plateaus.

Caldera collapse

Formation of a large volcanic depression when a magma chamber empties.

Weathering

Breakdown of rocks into smaller pieces by physical, chemical, or biological means.

Freeze–thaw action

Repeated freezing and thawing of water in cracks that causes rock to split.

Exfoliation

Peeling of rock layers due to pressure release or thermal expansion.

Hydrolysis

Chemical weathering reaction between minerals and water.

Oxidation

Breakdown of minerals when they react with oxygen, often forming rust.

Carbonation

Dissolving of carbonate rocks like limestone by carbonic acid in rainwater.

Biological weathering

Disintegration of rock by plant roots, animals, or microbes.

Erosion

The removal and transport of rock or soil by natural agents like water, wind, or ice.

Mass wasting

Downslope movement of soil or rock due to gravity.

Landslide

Rapid movement of rock or debris down a slope.

Slumping

Curved, rotational movement of saturated soil along a concave slip plane.

Soil creep

Very slow downslope movement of soil particles under gravity.

Fluvial erosion

Wearing away of land by rivers through hydraulic action, abrasion, and solution.

Hydraulic action

Force of moving water breaking rock particles from riverbanks or beds.

Abrasion

Scraping of rock surfaces by particles carried in water, wind, or ice.

Attrition

Rocks and pebbles colliding and breaking into smaller, smoother pieces.

Solution (fluvial)

Dissolving of soluble minerals in water.

Deposition (fluvial)

Laying down of sediment when a river loses energy.

Meander formation

Development of river bends through lateral erosion and deposition.

Oxbow lake formation

Cutoff of a river meander forming a separate crescent-shaped lake.

Delta formation

Deposition of river sediment at a river mouth into standing water.

Longshore drift

Movement of sediment along a coast by wave action at an angle.

Wave refraction

Bending of waves as they approach shore, focusing energy on headlands.

Constructive waves

Gentle waves depositing sediment to build up beaches.

Destructive waves

Strong waves that erode beaches and cliffs.

Marine deposition

Accumulation of sediment transported by waves and tides.

Cliff retreat

Landward erosion of cliffs by marine and subaerial processes.

Spit formation

Deposition of sand by longshore drift extending out from the coast.

Barrier island formation

Creation of offshore sandy islands from deposited sediments.

Glacial erosion

Carving and shaping of land by moving ice.

Plucking

Ice freezes onto rocks and pulls them away as glaciers move.

Abrasion (glacial)

Grinding of rock by debris carried in glacier ice.

Freeze–thaw weathering

Repeated freezing and melting that cracks rock in cold climates.

Deposition (glacial)

Laying down of till and outwash as glaciers melt.

Moraine formation

Accumulation of unsorted debris deposited by a glacier.

Cirque formation

Bowl-shaped depression formed at the head of a glacier.

U-shaped valley formation

Erosion of a V-shaped river valley into a U-shape by glaciers.

Drumlin formation

Streamlined hills of glacial till formed beneath moving ice.

Aeolian erosion

Removal and transport of material by wind in arid regions.

Deflation

Lifting and removal of fine sediment by wind.

Abrasion (aeolian)

Sandblasting of rock surfaces by airborne particles.

Dune formation

Accumulation of sand in mounds or ridges shaped by wind.

Desert pavement formation

Surface of coarse rock fragments left after wind removes fine sediment.

Biological weathering

Rock breakdown by plant roots, burrowing animals, or microbes.

Root wedging

Roots growing into cracks and breaking rock apart.

Burrowing

Animals disturb soil and move material downslope.

Lichen growth

Lichens chemically weather rock through organic acids.

Mass movement

Downslope transport of material under gravity.

Rockfall

Sudden free fall of rock from steep cliffs.

Mudflow

Rapid downhill flow of saturated soil and debris.

Earthflow

Slow to moderate movement of wet soil down a slope.