Weathering Flashcards
Denudation
Any process that wears away or rearranges landforms. Weathering, Erosion, Transportation, Deposition
Weathering
Weakening of rock… Decomposition of rock. First step in erosion process. Both physical and chemical.
Erosion
Detachment of sediment
Transportation
Movement of sediment
Deposition
Sediment coming to rest
Mechanical weathering
Rock is disintegrated, makes pieces of rock. Blistering, scaling, flaking.
Root Wedging
Mechanical. As roots grow larger in cracks they exert force
Biological
Mechanical. Roots/anchors (thallus) of plants on rocks, some bacteria and fungus eat rock and increases acidity
Thermal Expansion
Mechanical. All substances expand when heated, contract on cooling. Heats water in crack, reach boiling point, turn into water vapor, expands dramatically in phase change
Exfoliation
Mechanical. Layers peeling off a rock, like onion, most common in granite. Pressure release.
Chemical Weathering
Chemical changes within a rock, weakening rock structure as materials are removed, makes mechanical weathering and all other geomorphological processes easier.
Spheroidal Weathering
Inside-out chemical weathering process… Leads to rounding of edges of rocks and cracks that lead to expansion and a round rock.
Staining
Chemical. As weathering product is washed away.
Pitting
Chemical. Micro-erosion
Oxidation
Chemical. Removal of an electron, addition of oxygen atom, rusting… Increase volume and releasing new minerals
