Weathering* rock type/structure- minerals: quarts & granite resistant-differential weathering based on composition & structure* slope- steep =* rapid, gradual =* slow* climate- moisture and heat promote reactions (chem. react. prev. @ =* eq.) -carbonate rocks (calcite diss.) in different regions* time- hundreds/thousands years for a few mmSoils: The part of the regolith that can support rooted plants. Formed by the weathering of bedrock: mineral component mixed with organic material.* soil horizons: identifiable succession of subhorizontal weathered zones* distinct physical, chemical, and biological characteristics* collectively known as soil profile (parent material =* surface)* O- surface organic debris* A- humus, chemical leaching* E- gray/white, present in evergreen forests (acidic soil)* B- enriched in clay produced by weathering within the horizon* K- only in arid zones (rich in calcium carbonate)* C- deepest, slight weathered parent material, lacks distinct properties, yel/brn oxidation* soil forming factors: * time* climate- rain & temperature* composition of parent material* vegetation cover* soil organisms* topographySoil Types (influence the process, classified by chem/phys properties)* polar soils- well drained, lack well-developed horizons, weak oxidation-wetter env'ts: tundra causes water-logged, organic rich soil, A not B* temperature-latitude soils- well-developed horizons, unique to env't-deciduous Affisols, evergreen Spodosols, mountainous Entisols and Inceptisols, prairie Mollisols* desert soils- no leaching produces solid, impervious layer of caliche* tropical soils- heavy weathering, leaching produces iron-rich lateriteEnvironmental Aspects of Soils* rate of soil production: dependent on climate (in regolith, not bedrock (cw)* mod. T. & high R.- rapid, within 100s years* mod. T. & avg. R.- 100,000 years* low. T. & low. R.- millions of years* paleosols are ancient soils recorded in rock as unconformitiesSoil Erosion...
