GPHY 102 Lecture 15: L15

• School: Queen's University
• Department: Geography
• Course: GPHY 102
• Professor: Ryan K Danby

Document Summary

Weathering is the physical or chemical alternation of rock, usually involving disintegration to smaller elements (breaks pre-existing rock into small fragments or new minerals) Causes the decomposition, decay or rotting of minerals. Caused by internal disruptive forces (eg. reaction of mineral to water: common forces include hydrolysis, oxidation and carbonation. Hydrolysis = occurs when minerals are moistened: causes chemical alternation, but expansion as well which contributes to breakdown of rocks, e. g feldspar hydrolysis yields clay minerals ad (bi)carbonates. Oxidation = occurs when minerals in rocks react with oxygen: causes chemical alteration, formation of oxides, e. g iron and aluminum oxides, opposite reaction is reduction" (removal of oxygen) Carbonation/ acid action- creation of weak acids when compounds such as. Stalagmites grow from the floors of caves, usually round- topped, and are commonly caco3 (calcite or aragonite) Stalactites hand from the roofs of caves, commonly caco3, usually pointed , often begin growth as a soda straw .