GEOL 101 Lecture Notes - Lecture 9: Silicate Minerals, Weathering, Clay Minerals
Document Summary
Compare and contrast mechanical and chemical weathering. Define oxidation and explain how it breaks down minerals. Discuss the factors that are important to weathering rates. Define soils and explain the controls on soil formation. Identify the different layers found with a soil. Surface processes are responsible for the movement and transport of earth"s material. Weathering: physical breakdown/chemical alteration of rock at/near the earth"s surface. Mechanical (physical): destruction/breaking of rock into smaller pieces. Increase surface area makes rock more susceptible to further weathering. Repeated cycle of water freezing/thawing, results in break up of rock into smaller pieces. Removing overlying weight (pressure) from body of rock. Consequence: rock expands, begins to break apart. Material expansion when heated, contract when cooled. Activity of plants/animals results in physical break up of rock. Chemical: decomposition/dissolution of a rock by chemical agents (mainly water) Water is the most important agent involved in chemical weathering at the earth"s surface.