GGR227H5 Lecture Notes - Lecture 7: Pedogenesis, Parent Material, Mass Wasting
Document Summary
Weathering and erosion weathering (breaking down) of rocks in the earth"s crust is part of the rock cycle: mechanical weathering (e. g. , wind, freeze-thaw, roots) and chemical weathering (reactions that dissolve minerals, often involving dissolved co2) Weathering plays an important role in supplying long-term inputs of materials for: Erosion is the transport of weathered materials by air, water or ice (mass wasting is the: biogeochemical cycles, soil development, plant nutrients, etc. movement of materials by gravity; e. g. , rock fall, slumps) When weathering products accumulate (i. e. , no erosion) soil develops. Sediments are re-deposited weathered mineral/rock particles: sediments are deposited by wind (aeolian) or water (fluvial, lacustrine, soils are not deposited they form where sediments were already deposited, soil forms from parent material as a result of physical/chemical/biological processes. Solids (inorganic materials, decaying organic matter), water, air (with n2, o2, co2, Soils are capable of supporting plant growth. Parent material: geological or organic precursor to the soil.
