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

Grade 6 Science Worksheet

Circle the best answer.

1. 1.

   Drawing of a closed jar of cloudy water with gravel, sand and clay mixed through it. Esme shakes a closed jar of water, gravel, sand and clay, then sets it down to settle. Which layers form, from the bottom up?

   • Clay, then sand, then gravel on top
   • Gravel, then sand, then clay on top
   • Sand, then clay, then gravel on top
   • One mixed layer with no order
2. 2.

   Jun's map shows a river bend. Water flows fastest along the outside bank, X, and slowest along the inside bank, Y. Where does sand pile up into a sandbar?

   • Y, on the inside bend, where water is slow
   • Both banks equally
   • X, because erosion piles sand up
   • X, on the outside bend, where water is fast
3. 3.

   After days of heavy rain, a hillside slides down in a few minutes. Kira reads about it. Which agent moved the soil, and how fast?

   • Running water, over many centuries
   • Gravity, in minutes
   • Wind, over many years
   • Gravity, over millions of years
4. 4.

   Luz reads that the Colorado River carved the Grand Canyon. About how long did that take, according to the National Park Service?

   • About 50 years
   • One big flood, over a few days
   • About 5 to 6 million years
   • About 5,000 years
5. 5.

   Milo sorts changes to the land into fast and slow. Which change usually happens fast?

   • A flash flood moving boulders in an afternoon
   • Rain dissolving a limestone cave
   • A glacier carving a valley
   • A river carving a canyon
6. 6.

   Noah visits a limestone cave. Rainwater carrying a weak acid seeped through the rock for ages and dissolved it. Which process made the hollow space?

   • Erosion by wind
   • Deposition of new rock
   • Mechanical weathering by ice
   • Chemical weathering, dissolving the limestone
7. 7.

   Rock A cracked into sharp pieces of the same gray stone. Rock B turned rusty and crumbly. Which shows mechanical weathering, by Pia's clues?

   • Rock A, broken but still the same stone
   • Rock B, since its color changed
   • Neither; this is deposition
   • Both, since both weathered the same way
8. 8.

   Water expands by about 9% when it freezes. Ren reads about a rock crack that fills with water and freezes each winter night. What happens to the crack?

   • The water dissolves the rock into a new mineral
   • Freezing water pushes it wider, bit by bit
   • The ice carries the rock downhill right away
   • Nothing; ice is softer than rock
9. 9.

   A beach loses sand in winter storms and slowly gains it back in calm weather. Which pair names the two processes, says Zee?

   • Storms: erosion; calm weather: deposition
   • Storms: deposition; calm weather: erosion
   • Both seasons: weathering
   • Storms: weathering; calm weather: erosion
10. 10.

    A muddy stream flows into a quiet pond, and by the next day the pond water is clear. What happened to the mud, by Ari's thinking?

    • It dissolved and vanished
    • It was weathered into nothing
    • The stream's fast water kept it moving through
    • It settled to the bottom as the water slowed