Weathering and Soil

Weathering and Soil Chapter 4

4.1 Rocks and Weathering • Erosion • Breaking down of rock ___________________ • _______________________ of rock particles by: • Wind • Water • Ice • Gravity into smaller pieces Carrying away/removal

4.1 Rocks and Weathering • _____________ • Breaking down and wearing away of rocks and other substances • Forces involved: • ______________ • ______________ • ______________ • ______________ • ______________ Weathering water ice gases heat cold

4.1 Rocks and Weathering Mechanical Chemical rock physically broken up into smaller pieces uses chemical changes to break down rock break down rocks

4.1 Rocks and Weathering • Agents of mechanical weathering • Freezing and thawing • _____________________ • Release of pressure • ________________ • Actions of animals • ________________ frost wedging plant growth abrasion

4.1 Rocks and Weathering • Freezing and Thawing (Frost Wedging) • Water seeps into crack and air pockets • Water freezes and __________ making the crack __________ • Frost wedging causes ____________ and cracks in concrete or blacktop expands bigger potholes

4.1 Rocks and Weathering • Release of pressure • Material is removed from the rock’s surface • ________________________ • The release of pressure makes the outside of the rock to _______________in layers like an onion pressure is reduced peel and flake

4.1 Rocks and Weathering • Plant Growth • __________ of plants grow into spaces or cracks • They make the cracks bigger and _____________ apart • As the roots get bigger they pry the spaces or cracks ___________ Roots spreads them wider open

4.1 Rocks and Weathering • Actions of Animals • Animals _____________ in the ground • This _____________________ up the soil • Moles, prairie dogs, gophers, some insects burrow loosens and breaks up

4.1 Rocks and Weathering • Abrasion • Small particles of ______________ wear away at exposed rocks • Wind, water, or ice carry these particles • Works like __________ sand or rocks sandpaper

4.1 Rocks and Weathering • Agents of chemical weathering • ____________ • Oxygen • ____________ • Living organisms • ____________ Water Carbon dioxide Acid rain

4.1 Rocks and Weathering • Water • ______________ • Carry substances that dissolve rocks including: • Oxygen • Carbon dioxide • Other chemicals Dissolving rocks

4.1 Rocks and Weathering • Oxygen • Combines with _________ • This is called oxidation • This forms ________ • Rust softens rock and makes it crumble and gives it a red-brown color water rust

4.1 Rocks and Weathering • Carbon Dioxide • When dissolved in water it makes a weak acid called _________________ • Carbonic acid weathers rocks like ___________ ____________ carbonic acid marble and limestone

4.1 Rocks and Weathering • Living Organisms • Plants’ roots produce ___________ • These acids slowly ______________ around the roots • _________ (plants-like organisms that grow on rocks) produce weak acids that wear away rocks weak acids dissolve rocks Lichens

4.1 Rocks and Weathering • Acid Rain • Rainwater is ______________ • Burning of fossil fuels adds ___________ into the air with sulfur, carbon, and nitrogen compounds • These make stronger acids in the rainwater • Acid rain falls and ____________ weathers rock slightly acidic pollution rapidly

4.1 Rocks and Weathering • Factors that affect rate of weathering: • ______________ • Minerals that make up the rock • Permeability of the rock Type of rock

4.1 Rocks and Weathering • Factors that affect rate of weathering: • ___________ (average weather conditions) • Chemical reactions occur ________ in warmer climates • ____________________ Climate faster Warmer = faster

4.1 Rocks and Weathering • Factors that affect rate of weathering: • Climate (average weather conditions) • Chemical reactions occur faster in warmer climates • Warmer = faster

Weathering and Soil