When your test is turned in, you may:

1) Silent read each other’s rock star stories. They are in

your blue tubs.2) Silent read your own book.

Bell Ringer: In your IAN, Make a New Unit

Title Page.

Chapter 10Weathering and Soil Formation

Chap 10, Sec 1 (Weathering)

Objectives:1. Describe how ice, water, wind, gravity,

plants, and animals cause mechanical weathering.

2. Describe how water, acids, and air cause chemical weathering of rocks.

3. Does size make a difference?4. Please take out your Standards for Unit 2

from the blue tub and glue them on page one of this Unit 2 Section!

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.

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.

Procedure1. 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.

Analysis1. 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.

Tech Terms:1. Weathering (paste the green slip here,

then paste the white slips that belong with this word, below)

2. Erosion (paste the green slip here, then paste the white slips that belong with this word, below)

3. Deposition (paste the green slip here, then paste the white slips that belong with this word, below)

When you go on a walk, have you ever seen small rocks laying along the side of the path?

**Where did they come from? **Why are they there?

4. 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.

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

6. Abrasion- the grinding away 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.

Abrasion 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 Erosion in Nature? Plants & Animals

Plants 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! 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.

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 animals that contribute to weathering.

7. Chemical Weathering-The process by which rocks break down as a result of chemical reactions is called chemical weathering.

Common agents of chemical weathering are water, weak acids, and air.

(Paste organizer from “Wacky Weathering” on opposite page

or here)

Weathering

Type of: Type of:

List at least 1 bullet to describe List at least 1 bullet to describe