GL102 Lecture Notes - Lecture 5: Surface Runoff, Calcination, Particle Size
Document Summary
Lecture 4 - chapter 5 - weathering or soil. Soil forms on unconsolidated sediment transported from elsewhere. E. g. glacial deposits that cover much of canada. In general, longer soil has been forming, the thicker it becomes, and the less is resembles the parent material. Organisms influence a soil"s physical and chemical properties. Plants and animals supply organic matter to the soil. Microbes play a critical role in decay of plant and animal matter. Steep slopes often have poorly developed soils. Lowland, poory drained soil is typically thick, dark, and contains only partially-decayed organics. Optimum terrain is a flat-to-undulating upland surface, well drained, minimum erosion. Soil-forming processes operate from the surface downward. Horizons - vertical differences in soil - distinctive layers. Soil profile - vertical section (trench or pit) Five distinct horizons designated (surface downwards): o, a, e, b, and c. A horizon - mineral, some organic matter o and a horizons are topsoil.