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
   • Q, on the inside bend, where sand piles up in a bar
   • Neither; banks change just in big floods
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
   • R, the straight stretch, where the water speeds up
   • Q, the inside bend, where slow water drops sand
   • P, the outside bend, where fast water drops sand
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?

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

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

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

   Steep, narrow, dark rock walls with the river at the bottom. Noah's cousin says a canyon as deep as the Black Canyon of the Gunnison could form within one person's lifetime. Which response is best?

   • Disagree: canyons form by deposition
   • Agree: one strong flood could carve it
   • Agree: rivers carve that deep in about a century
   • Disagree: the river began cutting it about 2 million years ago
7. 6.

   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
   • It dissolves into the water there
   • The water picks up even more sand from the bottom there
   • It is weathered into clay there
8. 7.

   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?

   • Deposition of sugar dust
   • Erosion by wind in the jar
   • Mechanical weathering by pieces rubbing together
   • The sugar dissolving in water
9. 8.

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

   • Nothing; rain cannot move soil
   • Plant grass and shrubs whose roots hold the soil
   • Pile loose sand on top
   • Leave the slope bare so the rain can run off faster
10. 9.

    Waves keep carrying sand away from a town beach. Ari looks for an idea that works by slowing the water near shore. Which one?

    • A line of rocks offshore that breaks the waves
    • Removing the dune plants so sand can move freely
    • Digging the beach deeper
    • Speeding up the waves so sand settles
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
    • Water the field once a year
    • Nothing; wind cannot move soil
    • Plant rows of trees as a windbreak