Geology 12

Unit 3 Lesson 3: Deposition

Big Idea: What is deposition and how do humans impact it?

Outcomes:

  • 4.3.1 propose a course of action on social issues related to science and technology, taking into account human and environmental needs (118-9)
  • 4.3.2 develop, present and defend a position or course of action based on findings (215-5)
  • 4.3.3 compare and contrast particle size, shape, and degree of sorting in fluvial, glacial and aeolian deposits (363-10)
  • 4.3.4 relate weathering, erosion and deposition of sediment to the rock cycle (363-5)

What will I be doing?

Activity / Date Started? / Date Finished? / Marks/ Comments
1) What is deposition?
2) Webquest on deposition
3) Sedimentary rock lab

Use the following website to help you answer the questions below:

1)What is deposition?

2)How is it related to erosion and weathering?

3)What is horizontal sorting?

4)What are the major factors that affect deposition?

5)What is the difference between a graded bed and glacial deposition?

1)Go to the animation at the website above and explain how sediments are moving in a flowing body of water.

2)Go to the animation at the website above and explain what happens to sediments when a moving body of water enters a large body of water such as a lake or harbour.

3)Go to the above website and click on ‘1: Rivers and Deltas’ and explain how sediment is deposited in these bodies of water.

4)Go the above website and click on ‘2: Glaciers’ and explain how sediment is deposited by glaciers.

5)Go to the above website and click on ‘3: Hot Deserts’ and explain how sediment is deposited here.

Procedure:

  • Take your bottle filled with sand and water, and make sure the lid is securely fastened.
  • Turn the bottle side to side to stir up the water inside, be gentle we don’t want a mess.
  • Stop shaking the bottle and place it on the table in front of you. Watch as the sand settles to the bottom.

Answer questions in complete sentences:

  1. Where are the larger particles and why?
  2. Are there just large pieces at the bottom?
  3. As you look higher in the jar what is happening to the size of the sand grains?
  4. Did all of the particles settle out right away?
  5. When a river enters the ocean, the water slows down suddenly just like when you stopped shaking the flask. Which particles would you expect to drop closest to the mouth of the river?
  6. If you were to sample the sand near a rivers mouth and then take another sample father out to sea, what would you expect to find?
  7. What would settle out even farther that the sand?

Investigate the following diagram and answer the following questions

  1. How would sedimentation be different in an environment where a very slow moving river enters the ocean? Where there was a fast current?
  2. Many of the beaches off CapeBreton have much more coarse gravel and large rock fragments, while the beaches on the south or eastern shore tend to have less gravel, and more fine sand. Explain why this happens.
  3. What property of sedimentary rocks is used to identify most of them?