Chapters 7 - Erosion & Weathering Lecture notes

Erosion- removal and transport of weathered materials

Weathering - process that breaks down or changes rocks on or near Earth’s surface

Mechanical- breaks rocks and minerals into smaller pieces (physical) –Temperature, and pressure are involved in physical weathering –Frost wedging - repeated thawing and freezing of water, causes rocks to split –Exfoliation - outer rock layers stripped away

Chemical weathering - rocks and minerals undergo changes in composition –Chemical reactions –Rocks with calcite (limestone) –Warmer temperatures, increase reaction –Water can dissolve many rocks

Chemical weathering - rocks and minerals undergo changes in composition –Oxidation- chemical reaction of oxygen with other substances –Carbon Dioxide contributes –pH below 5.6 is acidic

Climate determines rate of weathering –Chemical weathering faster in warm, wet climates –Physical weathering faster in cool, dry climates Type of rock –Sedimentary weather faster

Surface area- more area, more weathering Topography- slopes have more erosion (gravity)