GEG 1301 Lecture Notes - Lecture 12: Dune, Landform

• School: University of Ottawa
• Department: Geography
• Course: GEG 1301
• Professor: Denis Lacelle

Document Summary

Similar to weathering, but the material is removed after breakdown. Occurs at all scales (from cm to km) and all landscapes (glacial, coastal, karst, aeolian) Erosional energy comes from potential and kinetic energy caused by. Uplifting: increases potential energy (what goes up must come down) Water and ice: move under the action of gravity, converts potential kinetic. Detachment: detachment forces (weathering, quarrying/plucking, abrasion, raindrop impact/rainsplash effects) must overcome all resistant forces (friction, cohesion, cementation, interlocking crystals) to release the material. Entrainment: the sediments are incorporated into the fluid flow (air, water, ice) Critical entrainment velocity varies with fluid type and particle size. Transport: 4 methods of transportation (suspension, saltation, traction & in solution/dissolved) Sorted: sorting of grain sizes due to settling out at different velocities. Coarser material is deposited first finer material. Unsorted deposits have a wide range of grain sizes in one place. Landform: a single, visible feature (mountain, sinkhole, sand dune, water feature)