GEO 1111 Lecture Notes - Lecture 14: Spheroidal Weathering, Granite Dome, Silicate Minerals

• School: University of Ottawa
• Department: Geology
• Course: GEO 1111
• Professor: Robert Jack Cornett

Document Summary

*** know how to use formulas, no need to memorize. Involves physical breakdown and chemical alterations of rock: mechanical, chemical. Both types work simultaneously and reinforce each other. Diffusion through a cell membrane, rust on a car, absorption are all proportional to area. Water works its way in cracks of rocks. As water freezes, it expands and moves rocks: sheeting or unloading. Masses of igneous rocks exposed by erosion and glaciation and slabs break loose. An exfoliation dome is formed after continuous weathering. Plant roots grow into fractures and expand them. Burrowing animals break down rocks: salt crystal growth. Most important agent is water: responsible for transport of ions. Ex : carbonic acid is created when carbon dioxide dissolves in raindrops. Oxygen combines with iron to form iron oxide (rust) Important in decomposing minerals (stable at a different regime) Silicates decompose by hydrolysis (clay minerals are the most abundant product of weathering only stale at surface of earth)