GLGY 202 Study Guide - Final Guide: Unicef, Tephra, Simile
Document Summary
Various definitions : fine grain mineral matter and organic matter (agricultural view, sequence of layers below earth"s surface (geoscientist view, any movable mass or unconsolidated material (engineer view) Hummus: upper part of soil which is decomposed litter. Mineral matter: soils contain minerals from i) local bedrock weathering into clay pieces or ii) comes from being transported in (like being blown in or carried by rivers). Described by using the triangular diagram, which has 3 variables, sand (2mm- 1/16mm (or 0. 074mm)), silt (0. 074-0. 004) and clay (<0. 004mm) composition. Note: clay has two meanings: a size meaning and a type of silica meaning. Clay minerals are mica-like sheet minerals which expands easily when water is entered (ie ventinite and montmirilanite. A horizon: top soil organic rich matter and some mineral material. Leaching occurs here. ( e horizon: composed of light-coloured matter which is a result of the leaching of iron bearing materials from above, this only develops after some time has elapsed.