GLG 111 Lecture Notes - Lecture 9: Pedogenesis, Basalt, Parent Material
Document Summary
Weathering two types the chemical and physical disintegration, decomposition and dissolution of rocks at or near the earths surface. Mechanical physical the destruction/breaking of rocks into smaller pieces (scratch, crush, etc. ) Chemical the decomposition/dissolution of a rock by chemical agents (mainly water) Mechanical weathering breaks rocks into smaller pieces thereby increasing the surface area. Frost wedging the repeated cycle of water freezing and thawing, results in the physical breakup of the rock into smaller pieces (ex. potholes) Unloading the process of removing the overlying pressure from a body of rock. Thermal expansion materials will expand when they are cooled. Biological activity the activity of plants or animals that result in the physical breakup of rocks (ex. trees growing in between rock) Chemical weathering decomposition/dissolution of a rock by chemical agents (mainly water) Water is the most important agent involved in chemical weathering at the earths surface. Carbonic acid is also a major agent in chemical weathering processes.
