1. Post-activity answers.
Seafloor Spreading
Post-activity answers.

2. 1. What is happening at Slit B
1. What is happening at Slit B? What feature occurs at the corresponding location on the seafloor/
Magma erupting; seafloor spreading

3. 2. What is happening at slits A and C
2. What is happening at slits A and C? What features occur at corresponding locations on the seafloor?
Subduction. Trenches.

4. 3. If you were to sample and date the rocks along the colored strip starting at slip B and moving toward slip A, what change, if any would you see in the age of the rock?
Younger rocks are near B; older rocks toward A

5. 4. If you were to sample and date the rocks along the colored strip starting at slip B and moving toward slip C, what change, if any would you see in the age of the rock?
Younger rocks are near B; older rocks toward C

6. 5. In this new model, what do the strips represent
5. In this new model, what do the strips represent? What do the colors represent?
Strips = new ocean floor
Colors = age of floor

7. New sealoor rock is continually being formed at mid-ocean ridges and old seafloor rock is continually removed at ocean trenches. If the rock on the continents is continually formed but not removed, how would the age of the oldest rocks on the continents compare with the age of the oldest rocks on the seafloor?
Oldest rocks on continents older than oldest rocks on seafloor

8. Easy to see convector belt effect. Hard to see recycling at trenches.
7. What are the strengths and weaknesses of this model for demonstrating seafloor spreading?
Easy to see convector belt effect.
Hard to see recycling at trenches.

9. 8. What causes the plates to be pulled apart?
Magma pushing up at divergent boundary

10. Plates are pulling apart at divergent boundaries.
9. Look at the map on the right showing some of Earth’s plates and the direction of their motion. What is happening to the Atlantic and Pacific Oceans.
Plates are pulling apart at divergent boundaries.