Ava Altmann
1/6/13
Magalloway
Rock Abrasion Science Report

Purpose: What effect does the length of time of abrasion have on the way rock particles weather? Rocks are constantly changing their size because of the weathering process. Weathering is when rocks are broken down by physical or chemical means. An example of physical weathering is abrasion. Wind, water, and gravity can cause abrasion to happen. For example, in a stream, the current pushes rocks forward, causing them to hit and rub against other rocks. This causes the rocks to abrade. The more time being abraded, the more rock mass lost.

Materials:
-Plastic container with a lid
-Presoaked rock chips
-Electronic scale
-Screen
-Clock or timer
-Paper towels
-Coffee filter
-Goggles

Procedure: *taken from Prentice Hall Earth Science Rock Abrasion Lab
1. Obtain a sample of presoaked rock chips and drain the to remove excess water. Note: place the rocks on the screen so that they do not get lost
2. Use the balance to measure out 100g of rock from your sample. Return the extra pieces to supply the container.
3. Place 100g of chips in the container provided
4. Add water to the container until it is about half full. Close the lid tightly over the container. Shake container at a constant rate for 3 minutes
5. Carefully pour the water from the container into a sink. Use the screen to make sure not even the smallest rock piece is lost.
6. Measure the mass of the chips again and record your result into a Data Table
7. Return the rock chips to the container, close the container, and repeat steps 4 through 6 four more times. Record the results after each 3 minutes of shaking, for a total of 15 minutes.
8. Graph the results, comparing mass