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?

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

   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?

   • Convergent: plates push together
   • Transform: plates slide past each other
   • No boundary; the ground is just cracked
   • Divergent: plates pull apart
3. 3.

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

   • Sea water carved them to match
   • They are rushing toward each other right now
   • It is just a coincidence
   • They were once joined and have moved apart
4. 4.

   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
   • Its seeds blew across the oceans
   • Those lands are still joined today
5. 5.

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

   • A few kilometers a year
   • They don't move
   • A few centimeters a year
   • A few meters a day
6. 6.

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

   • A car on a highway
   • Nothing; plates are fixed
   • Fingernails growing
   • A snail crawling
7. 7.

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

   • They move just at night
   • They don't move
   • They move too fast to see
   • They move just a few centimeters a year
8. 8.

   An ocean plate bending down under another plate, with the place where they meet unlabeled. Where an ocean plate sinks under another plate, what forms? Tala checks the cross-section.

   • A lava ocean opening up
   • A long sliding fault
   • A tall ridge of brand-new seafloor rock
   • A deep trench, with volcanoes nearby
9. 9.

   Cross-section, not to scale: two ocean plates moving apart, with magma rising between them under the sea floor. Where two ocean plates pull apart, what forms on the sea floor, according to Zee's book?

   • A trench, where crust sinks
   • A ridge, where magma makes new crust
   • Tall mountains pushed up by crashing plates
   • An open gap down to liquid lava
10. 10.

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

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