1. Mechanical Weathering

2. What is Mechanical Weathering? Weathering where the chemical make up of the rock is not changed, but the rock is broken into smaller pieces

3. What are the different types of mechanical weathering? Root Action Rapid Temperature Change Ice Wedging

4. Root Action Root Action is the breaking of rock as tree roots grow through the cracks in rocks As the root grows bigger, it forces the rock apart Where is a common place around us to find examples of root action?

5. Root Action Sidewalks are often broken as tree roots grow This happens when trees are planted too close to sidewalks or roads

6. Ice Wedging Ice Wedging is when water gets into cracks in a rock and freezes. When water freezes, it expands and makes the crack bigger A few rounds or this will make the rock weak and it will break apart

8. Where might I find an example of ice wedging? Broken Curbs and Potholes in the Road are often caused by the repeated freezing and thawing of water in cracks.

9. Repeated Freezing and Thawing This occurs in places where temperatures change drastically between day and night

10. Temperature Changes During the daytime when it is very hot rocks expand slightly At night when temperatures drop drastically the rock contracts slightly Repeated expanding and contracting causes the rock to crumble. Where is there a place where temperatures change greatly?

11. The Desert!!! During the day temperatures can reach 115 degrees! At night temperatures can drop to 50 degrees! That’s a change of 65 degrees!

12. Abrasion Abrasion is the scraping away of tiny pieces of rock material as other pieces of sediment are being moved This can be caused by the: –Wind –Running Water –Glaciers –Avalanches

13. Abrasion Rock features like this are caused by wind abrasion Blowing wind scrapes away at the rock

14. Abrasion Rocks that have been in a river for a long time are often smooth and rounded because of abrasion Smaller rocks bang and scrape into other rocks as they move along.

15. The End!!!