Geology Unit L3
This document was uploaded by user and they confirmed that they have the permission to share it. If you are author or own the copyright of this book, please report to us by using this DMCA report form. Report DMCA
Overview
Download & View Geology Unit L3 as PDF for free.
More details
- Words: 326
- Pages: 9
Geology Unit Lesson 3: Earth’s Weathered Crust
09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
1
Weathering is • the process in which rocks are exposed to the elements (wind, water, temperature) and gradually break down. • Two types of Weathering: – Chemical Weathering – Mechanical Weathering 09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
2
Chemical Weathering • Breakdown of rocks caused by chemical reactions with other substances. • Result is a change in the chemical composition of the rocks. Canyon de Chelly, National Monument, Arizona
09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
3
Chemical Weathering Oxygen Iron in rocks rusts due to Oxygen in air.
Acid Rain Made these rocks jagged.
Rain water Plant Acids Break down rock. 09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
Weathered Badlands National park In South Dakota 4
Mechanical Weathering •
The physical breakdown of rocks into smaller pieces. • Gradually reduces the rocks to tiny particles that make up soil. 3. Wind produces
09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
5
Mechanical Weathering 3. Ice Wedging - Water freezes in the rock’s cracks.
2. Roots of plants wedge into rocks. Rocks break into smaller pieces.
4. Temperature changesCauses rock to expand and contract then break apart. 09/30/08
Rocks break apart.
5. Pressure breaks apart rock
Mrs. S. Iannacci - DSM Earth's Processes
6
Examples of Mechanical Weathering • The Grand Canyon • 4 heads – Washington, Jefferson, Roosevelt and Lincoln – patched every year due to wind. • Weeds on Jefferson’s cheeks are mowed to prevent acids from plant roots 09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
7
Soil • Type of soil that is produced by weathering depends on the type of rock that is broken down. – Sandstone and quartz breaks down into sand. – Feldspar produces clay. 09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
8
Review of Weathering
• http:// www.geography.ndo.co.uk/animationsweather
09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
9
09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
1
Weathering is • the process in which rocks are exposed to the elements (wind, water, temperature) and gradually break down. • Two types of Weathering: – Chemical Weathering – Mechanical Weathering 09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
2
Chemical Weathering • Breakdown of rocks caused by chemical reactions with other substances. • Result is a change in the chemical composition of the rocks. Canyon de Chelly, National Monument, Arizona
09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
3
Chemical Weathering Oxygen Iron in rocks rusts due to Oxygen in air.
Acid Rain Made these rocks jagged.
Rain water Plant Acids Break down rock. 09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
Weathered Badlands National park In South Dakota 4
Mechanical Weathering •
The physical breakdown of rocks into smaller pieces. • Gradually reduces the rocks to tiny particles that make up soil. 3. Wind produces
09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
5
Mechanical Weathering 3. Ice Wedging - Water freezes in the rock’s cracks.
2. Roots of plants wedge into rocks. Rocks break into smaller pieces.
4. Temperature changesCauses rock to expand and contract then break apart. 09/30/08
Rocks break apart.
5. Pressure breaks apart rock
Mrs. S. Iannacci - DSM Earth's Processes
6
Examples of Mechanical Weathering • The Grand Canyon • 4 heads – Washington, Jefferson, Roosevelt and Lincoln – patched every year due to wind. • Weeds on Jefferson’s cheeks are mowed to prevent acids from plant roots 09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
7
Soil • Type of soil that is produced by weathering depends on the type of rock that is broken down. – Sandstone and quartz breaks down into sand. – Feldspar produces clay. 09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
8
Review of Weathering
• http:// www.geography.ndo.co.uk/animationsweather
09/30/08
Mrs. S. Iannacci - DSM Earth's Processes
9
