POD # 13 Fossil Post Test *Use the test to answer the following: 1. Explain why the correct answer for #6 is C instead of A. 2. What is the correct answer for question # 10? 3. Explain why the correct answer for # 17 is C. 4. What is the correct answer to # 19?

POD #14 Weathering 1. What is the difference between weathering and erosion? 2. What are three causes of weathering? 3. What is uniformitarianism? 4. What does permeable mean? 5. What does abrasion mean?

WEATHERING

What is weathering? Weathering is the very slow process of breaking down rocks into smaller and smaller pieces. Weathering is the very slow process of breaking down rocks into smaller and smaller pieces.

What are the two types of weathering? Mechanical Mechanical Chemical Chemical

What is mechanical weathering? Mechanical weathering is the breakdown of rock into smaller and smaller pieces by physical means. Mechanical weathering is the breakdown of rock into smaller and smaller pieces by physical means.

What causes mechanical weathering?

Temperature Extreme changes in daytime and nighttime temperatures cause rocks to crack. Extreme changes in daytime and nighttime temperatures cause rocks to crack. Heating > expands Heating > expands Cooling > contracts Cooling > contracts

Rocks crack when constantly subjected to uneven rates of temperature change. Rocks crack when constantly subjected to uneven rates of temperature change.

Stone Mountain

Water When water seeps into the cracks in rocks and freezes, it expands, making cracks larger eventually breaking the rock into pieces. When water seeps into the cracks in rocks and freezes, it expands, making cracks larger eventually breaking the rock into pieces.

Ice causes weathering

Vegetation Roots of plants can grow in cracks of rocks, breaking them down. Roots of plants can grow in cracks of rocks, breaking them down.

Tiny plants, such as moss, are usually the first to grow in small cracks. Then, after they widen the cracks, larger plants may crack the rocks even more. Tiny plants, such as moss, are usually the first to grow in small cracks. Then, after they widen the cracks, larger plants may crack the rocks even more.

Vegetation cracks rock Vegetation cracks rock

Wind The force of wind pushes against rock, but it can also carry particles of sand or soil that will wear away rocks. The force of wind pushes against rock, but it can also carry particles of sand or soil that will wear away rocks.

Wind shapes rock

Carved by blowing sand

Gravity Rocks falling on one another cause them to break and wear away. Rocks falling on one another cause them to break and wear away.

Gravity causes landslides

Animals By burrowing in the soil, animals move soil particles around exposing fresh surfaces to continue weathering. By burrowing in the soil, animals move soil particles around exposing fresh surfaces to continue weathering.

Frogs and other animals dig in the soil

What is chemical weathering? Chemical weathering is the breaking down of rocks into smaller pieces by changing the chemical composition of the rock. Chemical weathering is the breaking down of rocks into smaller pieces by changing the chemical composition of the rock.

What causes chemical weathering?

Oxidation Oxygen in the air can react with certain deposits in rocks, such as iron, weakening the rocks and causing them to crumble. Oxygen in the air can react with certain deposits in rocks, such as iron, weakening the rocks and causing them to crumble.

Arches National Park, Utah

Acid Rain Rain that comes in contact with contaminants, such as industrial exhausts and becomes acidic. Rain that comes in contact with contaminants, such as industrial exhausts and becomes acidic.

Acid rain will slowly dissolve minerals in rocks causing them to become brittle and eventually crumble. Acid rain will slowly dissolve minerals in rocks causing them to become brittle and eventually crumble.

Water Over long periods of time, water can break down hard rock like granite. Over long periods of time, water can break down hard rock like granite.

Some ground water contains weak acids. When this ground water comes in contact with limestone, the limestone breaks down. Some ground water contains weak acids. When this ground water comes in contact with limestone, the limestone breaks down.

Acid rain changes the shapes of statues

Acid Rain eats away statues

Acids in Living Things Lichens produce organic acids that can slowly break down rock. Lichens produce organic acids that can slowly break down rock.

Lichens

What is the difference in mechanical and chemical weathering? What is the difference in mechanical and chemical weathering?

POD # 15 Mechanical and Chemical Weathering 1. List three examples of mechanical weathering. 2. List three examples of chemical weathering. 3. What is the one major difference between chemical and mechanical weathering?

Mechanical or chemical? Chemical Chemical

Mechanical or chemical? Chemical Chemical

Mechanical or chemical? Mechanical Mechanical

Mechanical or chemical? Mechanical Mechanical

Mechanical or chemical? Chemical Chemical

Mechanical or chemical? Mechanical Mechanical

Mechanical or chemical? Mechanical Mechanical

Mechanical or chemical? Chemical Chemical

Mechanical or chemical? Mechanical Mechanical

POD # 16 Review