GEOL 1001 : Geol Exam 2 Study Guide
Document Summary
Mechanical weathering: processes, frost action: water freezes and thaws repeatedly in cracks and pores in rocks. Important in cooler climates: ex. frost wedging, pressure release: exposed rocks release contained energy by expansion. Joints are parallel to exposed surface: easy for slabs to slide off, thermal expansion and contraction, volume of rocks change as they heat and cool. More prominent in areas with varying temps desert environment: rocks are poor conductors, differential heating between outside and inside, dark mineral color attracts more heat, others: Chemical weathering: *chemical alteration of parent material. Ions of a substance separate in a liquid, substance dissolves: water is a common solvent. It is a polar molecule: water will not dissolve all minerals. If water is slightly acidic it may dissolve formerly insoluble minerals. Form reddish or yellow iron oxides from iron rich minerals. Slow process that alters ferromagnesian silicates: hydrolysis.
