Moving plates, and the clues that they move
Grade 6 Science Worksheet - Building Confidence
Circle the best answer.
In Bo's next cross-section, the arrows point toward each other and the crust crumples upward. Which kind of boundary is it?
- Divergent: plates pull apart
- Transform: plates slide past each other
- Convergent: plates push together
- Plates drifting on liquid lava
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
- Convergent: plates push together
- Divergent: plates pull apart
- Transform: plates slide past each other
The coasts of South America and Africa fit together like puzzle pieces. What does Jun conclude?
- They were once joined and have moved apart
- It is just a coincidence
- Sea water carved them to match
- They are rushing toward each other right now
Fossils of the same ancient plant, Glossopteris, appear in South America, Africa, India, Antarctica and Australia. What does Milo conclude?
- Each land grew it separately by chance
- Those lands are still joined today
- Its seeds blew across the oceans
- Those lands were once joined together
Noah reads the USGS page on plates. About how fast do plates move?
- A few kilometers a year
- A few meters a day
- A few centimeters a year
- They don't move
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
Ren wonders why nobody notices the continents moving. Which answer is right?
- They move just a few centimeters a year
- They move just at night
- They don't move
- They move too fast to see
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 deep trench, with volcanoes nearby
- A long sliding fault
- A lava ocean opening up
- A tall ridge of brand-new seafloor rock
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 ridge, where magma makes new crust
- Tall mountains pushed up by crashing plates
- A trench, where crust sinks
- An open gap down to liquid lava
Where two plates grind sideways past each other, what does Esme expect to find?
- Nothing, since plates are fixed
- A new ridge
- Earthquakes along a long fault
- A deep trench