Weathering: The Breakdown of Rocks
Mechanical vs. Chemical weathering
Mechanical Weathering
Frost wedging and crystal growth
Abrasion
Thermal Expansion
Exfoliation
Chemical Weathering
Dissolution by
Weak
Acid
Water + Carbon Dioxide = Carbonic Acid
Hydrolysis
Feldspar + Acid + Water = Clay + Dissolved components
Oxidation
Iron in silicates + Oxygen = Iron oxide
Weathering Rates
Hot, Wet Climate speed up
Organisms speed up
Unstable (high T) minerals go faster
Soils
Regolith = weathered layer (soil = organic material + regolith)
Development of Soil Horizons: O, A, E, B, C
Soil classification (e.g. mollisols; inceptisols)