Types of Weathering

Kim BennisonKaty HoganAlex Gage

Kelly Fischer

Mechanical/Physical Weathering

• Exfoliation

• Ice Wedging

• Organic Wedging

• Abrasion

Exfoliation

When a rock has heat exerted upon it, along with pressure, it separates into layers.

Ice Wedging

When water leaks into the cracks of rocks, it freezes and causes the rock to crack.

Organic Activity

This occurs when burrowing animals, humans, or plants interfere and work their way into rocks.

Abrasion

Abrasion occurs when rocks rub against eachother and become rounded.

Chemical Weathering

• Hydrolysis

• Oxidation

• Dissolution

• Acid – Carbonation– Precipitation– Plant Acid

Hydrolysis

When rocks sit in water for extended periods of time they begin to break down and have a clay-like texture.

Oxidation

When oxygen reacts with iron in rocks, they rust, taking on a red-orange color.

Dissolution

Rocks, when in water, react with acids in the water and dissolve. A clue that this has happened to a rock is the presence of small holes.

Acid 1

• Carbonation- water absorbs carbon dioxide when rain falls or from decaying organic material. The carbon dioxide dissolved in water forms carbonic acid that reacts with many common minerals.

Acid 2

• Precipitation- Water in the atmosphere absorbs sulfur oxides and nitrogen oxides. Through a series of chemical reactions these pollutants are converted into acids that are a cause of acid precipitation.

Acid 3

• Plant Acid- When plants decay they release acids that react with the minerals in rocks.