Weathering and Soil Formation Bell Ringer: In your HSN, After the Unit 2 Title Page, label: Chapter 10: Weathering and Soil Formation Then, glue in your new standards And study guide if you haven’t!

Describe how water, acids, and air cause chemical weathering of rocks. Chap 10, Sec 1 (Weathering) Objectives: Please copy in your HSN! Describe how ice, water, wind, gravity, plants, and animals cause mechanical weathering. Describe how water, acids, and air cause chemical weathering of rocks. Does size make a difference?

When you go on a walk, have you ever seen small rocks laying along the side of the path or on the side of a creek? **Where did they come from? **Why do you think they are they there?

Two hundred years ago, a forest grew where these barren canyons are now. Today, the towering walls of Providence Canyon in southwestern Georgia stand as a testament to the power of rushing water. In the early 1800s, farmers cleared the land to make room for crops. In less than 200 years, rains and flash floods eroded the soil to form the canyons. What went wrong?

There are 2 Types of Weathering= Mechanical and Chemical Copy your numbered techterms! 1. Mechanical Weathering: the breakdown of rock into smaller pieces by physical means. Agents of mechanical weathering include ice, wind, water, gravity, plants, and even animals.

Examples of Mechanical Weathering:

Examples of Mechanical Weathering: 2 Examples of Mechanical Weathering: 2. ice wedging – a type of frost action (weathering from ice) occurs when wedges of ice in rock widen and deepen the existing cracks.

3. Abrasion- the grinding away/rubbing of rock by rock particles carried by water, ice, wind, or gravity. As you scrape a piece of chalk against a board, particles of the chalk rub off to make a line on the board and the piece of chalk wears down and becomes smaller. The same process, called abrasion, happens with rocks.

3 Abrasion Examples in Nature: Water: When rocks and pebbles roll along the bottom of swiftly flowing rivers, they bump into and scrape against each other. The weathering that occurs eventually causes these rocks to become rounded and smooth. Wind : When wind blows sand and silt against exposed rock, the sand eventually wears away the rock’s surface to a smooth sheet. Gravity : Avalanches; rocks fall on one another. You can imagine the forces rocks exert on each other as they tumble down a mountainside, jagged in appearance.

Other factors of Weathering in Nature? Plants & Animals

4. Plants: Plants often send their roots into existing cracks in rocks. As the plant grows, the force of the expanding root becomes so strong that the crack widens. You may not think of plants as being strong, but some plants can easily break rocks. Have you ever seen sidewalks and streets that are cracked because of tree roots? Roots don’t grow fast, but they certainly are powerful!

5. Animals: Believe it or not, earthworms cause a lot of weathering! They burrow through the soil and move soil particles around. This exposes fresh surfaces to continued weathering. Would you believe that some kinds of tropical worms move an estimated 100 metric tons of soil per acre every year? Ants, worms, mice, coyotes, and rabbits are just some of the other animals that contribute to weathering.

6. Chemical Weathering- The process by which rocks break down as a result of chemical reactions. Common agents of chemical weathering are water, weak acids, and air.

“DIRTY WORDS” Basics Due ______________ 3-5 minute presentation minimum Creative, Innovative, Visual Aid No power point Rubric Included Examples?

In Summary: weathering brainpop

Ice Wedging & Charcoal

Ice Weathering & Erosion

In this chapter, you will learn about the processes and rates of weathering. Complete this activity to learn about how the size and surface area of a substance affects how quickly the substance breaks down. Procedure 1. Fill three small cups about half full with water. 2. Add one sugar cube to one container. 3. Add 1 tsp of granulated sugar to the other container. 4. Try 1 tsp of brown sugar as well! 5. Using one spoon for each container, take turns with your partner and stir the water and sugar in each container at the same rate. 6. Using a stopwatch, measure how long it takes for the sugar to dissolve in each container.

Analysis 1. Did the sugar dissolve at the same rate in both containers? Explain why or why not. 2. Do you think one large rock or several smaller rocks would wear away faster? Explain your answer.