5.7: Plate Tectonics- Challenge 1
- Page ID
- 5385
- 1. Historically, ___ covered most of the earth, but today they form only on land and near the poles.
- glaciers
- 2. ___ of prehistoric organisms have been found on widely separated continents, suggesting that these organisms once lived in the same regions or could travel between them easily.
- Fossils
- 3. The Theory of Continental Drift states that ___.
- the earth's crust consists of several different continental plates that are constantly moving.
- 4. Scientists rejected Wegener's theory, because ___.
- no plausible mechanism to explain continental movement was known
- 5. Alfred Wegener died in ___ on an expedition to ___.
- 1930; the Greenland icecap
- 6. Magnetic crystals in older rocks of the same age on the same continent point to ___.
- the same point, but not the current magnetic pole
- 7. What line of evidence made scientists realize that Wegener was right about continental drift?
- Apparent polar wander
- 8. ___ crystallizes from fluid lava and points to the north magnetic pole as the lava cools.
- Magnetite
- 9. Flat-topped mountains in the ocean are known as ___.
- guyots
- 10. Who proposed the theory of seafloor spreading in the early 1960s?
- Harry Hess