Weathering, erosion and deposition: how land is worn down and built up

Grade 6 Science Worksheet - Challenge Me

Circle the best answer.

2. 1.

   On Esme's river map, P is the outside bank of a bend, Q the inside bank, and R a straight stretch. Over many years, which bank wears away most?

   • Both banks wear away equally
   • P, on the outside bend, where water is fastest
   • Neither; banks change just in big floods
   • Q, on the inside bend, where sand piles up in a bar
3. 2.

   On the same map, which spot does Jun predict will grow new land over the years?

   Use the picture in question 1.

   • P, since erosion builds land there
   • Q, the inside bend, where slow water drops sand
   • P, the outside bend, where fast water drops sand
   • R, the straight stretch, where the water speeds up
4. 3.

   Side view, not to scale. A dam slows a river into a long lake. Over many years, what does Kira predict builds up on the lake floor behind the dam?

   • Weathered rock from the dam itself
   • Sediment, dropped where the water slows
   • Less sand, since the water there moves faster
   • Nothing; the dam stops erosion entirely
5. 4.

   Luz's friend says weathering and erosion are two words for the same thing. Which response is best?

   • Agree: and water is the one agent for both
   • Agree: both words mean rock slowly wearing down over time
   • Disagree: weathering breaks rock; erosion moves the pieces
   • Disagree: erosion is when pieces are dropped
6. 5.

   A post claims only water shapes land, because wind is too weak to move rock. Milo checks it. Which response is best?

   • Agree: wind can weather rock but cannot move it
   • Agree: water does the shaping
   • Disagree: wind melts rock in deserts
   • Disagree: wind carries sand and builds dunes
7. 6.

   Gentle slope, 20 g of sand moved; medium slope, 45 g; steep slope, 80 g. Pia's class read about a stream-table test: the same water poured for 1 minute down sand at three slopes. What does the data show?

   • The sand was weathered, not moved
   • Slope makes no difference
   • Steeper slopes mean faster water and more erosion
   • Steeper slopes make the water drop more of its sand
8. 7.

   At the bottom of the stream table, the water spreads out and slows. What does Ren predict happens to the sand there?

   • It settles into a fan, like a small delta
   • The water picks up even more sand from the bottom there
   • It dissolves into the water there
   • It is weathered into clay there
9. 8.

   Tala's class shook sugar cubes in a closed, dry jar for 1, 3 and 5 minutes. The cubes got smaller and rounder each time. What does this model?

   • Erosion by wind in the jar
   • Mechanical weathering by pieces rubbing together
   • The sugar dissolving in water
   • Deposition of sugar dust
10. 9.

    Rain keeps washing soil off a bare slope beside Zee's school. Which plan would slow the erosion most?

    • Leave the slope bare so the rain can run off faster
    • Plant grass and shrubs whose roots hold the soil
    • Nothing; rain cannot move soil
    • Pile loose sand on top
11. 10.

    Wind blows dry topsoil off a flat, bare farm field. Which plan does Bo pick to help most?

    • Plow the field bare and smooth so the dust settles
    • Nothing; wind cannot move soil
    • Plant rows of trees as a windbreak
    • Water the field once a year