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?

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

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

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

   • One big flood, over a few days
   • About 50 years
   • About 5,000 years
   • About 5 to 6 million years
4. 4.

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

   • A river carving a canyon
   • A glacier carving a valley
   • Rain dissolving a limestone cave
   • A flash flood moving boulders in an afternoon
5. 5.

   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?

   • Chemical weathering, dissolving the limestone
   • Deposition of new rock
   • Erosion by wind
   • Mechanical weathering by ice
6. 6.

   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?

   • Both, since both weathered the same way
   • Neither; this is deposition
   • Rock B, since its color changed
   • Rock A, broken but still the same stone
7. 7.

   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
   • Nothing; ice is softer than rock
   • Freezing water pushes it wider, bit by bit
   • The ice carries the rock downhill right away
8. 8.

   “in jumbled order” Three events: a river drops sand in a lake, ice cracks a cliff, and the river carries the pieces. Which order does Tala choose?

   • Ice cracks cliff, river drops sand, river carries pieces
   • Ice cracks cliff, river carries pieces, river drops sand
   • River carries pieces, ice cracks cliff, river drops sand
   • River drops sand, river carries pieces, ice cracks cliff
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?

   • Both seasons: weathering
   • Storms: deposition; calm weather: erosion
   • Storms: erosion; calm weather: deposition
   • 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 was weathered into nothing
    • It settled to the bottom as the water slowed
    • The stream's fast water kept it moving through
    • It dissolved and vanished