Activity 4 - Graded sediment

Learning intention:

  • We are learning to understand how sediment settles out in water, and how we can use that to undertand how sedimentary rocks are formed.

Language

Graded - this means sorting from big to little. In school, students test marks are graded - they are sorted from highest to lowest. Fruit is graded - from biggest to smallest, or from best quality to fruit just for juice.

Sediment - usually pebbles, sand, mud, grit etc - that settles out from water.

Sedimentary rock - rock that is hardened pebbles, sand, mud, grit ...

Materials

  1. Glass jar

  2. Sand, mud, pebbles

  3. Water

Activity

  1. Mix up about one cup of sand, mud, and pebbles

  2. Place it into a glass jar

  3. Add enough water to nearly fill the jar

  4. Put the lid on firmly

  5. Shake for about 15 seconds

  6. Take a close-up photo of the sediment in the jar (leave the lid on)

  7. Leave the jar to settle overnight

  8. Take a photo of the sediment the next morning

  9. Look at some of the rock samples in th room - do any of them show grading of the sediment.

Follow up

Check out the photos of some of the graded sedimentary rocks: