Moving plates, and the clues that they move

Grade 6 Science Worksheet - Building Confidence

Circle the best answer.

1. 1.

   Cross-section, not to scale. Ari's cross-section shows two plates with arrows pointing away from each other and magma rising between them. Which kind of boundary is it?

   • Convergent: plates push together
   • Divergent: plates pull apart
   • Transform: plates slide past
   • No boundary; plates don't move
2. 2.

   In Bo's next cross-section, the arrows point toward each other and the crust crumples upward. Which kind of boundary is it?

   • Convergent: plates push together
   • Divergent: plates pull apart
   • Transform: plates slide past each other
   • Plates drifting on liquid lava
3. 3.

   Seen from above, Kira's map shows two plates with arrows pointing in opposite directions along their shared edge. Which kind of boundary is it?

   • No boundary; the ground is just cracked
   • Transform: plates slide past each other
   • Convergent: plates push together
   • Divergent: plates pull apart
4. 4.

   The coasts of South America and Africa fit together like puzzle pieces. What does Jun conclude?

   • They are rushing toward each other right now
   • Sea water carved them to match
   • They were once joined and have moved apart
   • It is just a coincidence
5. 5.

   Map of South America and Africa today, with matching fossil marks on the two coasts across the Atlantic Ocean. Fossils of Mesosaurus, a small freshwater reptile, turn up in both South America and southern Africa. What explains this, by Luz's reasoning?

   • The continents were joined when it lived
   • Its fossils floated over on pieces of driftwood
   • It walked across a long land bridge
   • It swam across the Atlantic Ocean
6. 6.

   Fossils of the same ancient plant, Glossopteris, appear in South America, Africa, India, Antarctica and Australia. What does Milo conclude?

   • Those lands were once joined together
   • Each land grew it separately by chance
   • Those lands are still joined today
   • Its seeds blew across the oceans
7. 7.

   Noah reads the USGS page on plates. About how fast do plates move?

   • A few meters a day
   • A few kilometers a year
   • They don't move
   • A few centimeters a year
8. 8.

   USGS compares the speed of plates with something that grows on Pia's own hands. What is it?

   • Nothing; plates are fixed
   • A car on a highway
   • A snail crawling
   • Fingernails growing
9. 9.

   Ren wonders why nobody notices the continents moving. Which answer is right?

   • They move too fast to see
   • They don't move
   • They move just at night
   • They move just a few centimeters a year
10. 10.

    Where two plates grind sideways past each other, what does Esme expect to find?

    • Nothing, since plates are fixed
    • Earthquakes along a long fault
    • A new ridge
    • A deep trench