Earth Science
Surface Processes and Landforms
Influences on Weathering
Study Tip
To help remember how climate affects weathering, remember the letter “w.” Wetter, warmer climates have greater weathering.
Rock and Mineral Type
- Different rock types weather at different rates
- Certain types of rocks are very resistant to weathering
- Igneous rocks, especially intrusive igneous rocks such as granite, weather slowly because water cannot easily penetrate them
Study Tip
Study Tip
The same way a person may cast a shadow over another person when they stand under the sun, planets or celestial bodies that have aligned themselves cast shadows over one another as well.
To help remember how climate affects weathering, remember the letter “w.” Wetter, warmer climates have greater weathering.
- Other types of rocks, such as limestone, are easily weathered because they dissolve in weak acids
- Rocks that resist weathering remain at the surface and form ridges or hills
- Different minerals also weather at different rates
- Some minerals in a rock might completely dissolve in water, but the more resistant minerals remain
- When a less resistant mineral dissolves, more resistant mineral grains are released from the rock
The Shiprock formation in northwest New Mexico is the central plug of resistant lava from which the surrounding rock weathered and eroded away.
Climate
- Climate of a region strongly influences weathering
- Determined by the temperature of a region plus the amount of precipitation it receives
- Weather averaged over a long period of time
- Chemical weathering increases as…
- Temperature increases: chemical reactions proceed more rapidly at higher temperatures
- Precipitation increases: more water allows more chemical reactions
- Cold, dry climate produces lowest rate of weathering
- The warmer a climate is, the more types of vegetation it will have and the greater the rate of biological weathering
Resources from Weathering
- Some resources are concentrated by weathering processes
- In tropical climates, intense chemical weathering carries away all soluble minerals, leaving behind just the least soluble components
Wet, warm climates have the most weathering
Concept Check
- What types of rocks weather most readily? What types weather least readily?
- What climate types cause more intense weathering? What climate types cause less intense weathering?
- How does bauxite form?
