External Processes
Processes occurring near Earth's surface, powered by gravity or the sun
External Processes
Crack expansion due to ice crystallization
Frost wedging
Oxygen reacting with minerals, especially iron, to form rust
Oxidation
Soil classification system
Soil taxonomy
Transfer of rock downslope due to gravity
Mass movement
Transport of weathered material off-site
Erosion
Weathering due to organismal activity
Biological activity
Process where different rock parts weather at different rates, creating uneven formations
Differential weathering
Best soil texture for plant growth
Loam
Downward sliding of a coherent mass along a curved surface
Slump
Oversteepened slopes or removal of vegetation increase likelihood of this process
Mass Movement
Erosion of overlying material revealing exfoliation domes
Unloading
These two factors cause differential weathering
Rock strength, exposure to environmental factors
Removal of soluble substances from upper soil layers, often moving them downward
Leaching
Slow downslope movement of water-saturated soil, common over permafrost
Solifluction
Physical breakdown of rocks at the surface (on site)
Weathering
Removing onion-like layers, forming exfoliation domes
Sheeting
Gradual rounding of sharp edges and corners on rocks
Spheroidal weathering
Decayed organic material in soil
Humus
Angle at which loose materials remain stable
Angle of repose
Processes occurring under Earth's surface, powered by the geothermal gradient
Internal processes
Growth of this from seawater deposition and evaporation
Salt crystal
Weak acid formed from water and CO₂ that reacts with carbonates
Carbonic acid
Regolith with added organic matter, water, and air
Soil
Sudden movement of large quantities of rock downhill
Landslide