Introduction -
After a triumphant return from the deep rain forests, the Captain emerges with a colorful parrot perched on the Captain's shoulder. With a proud smile, the Captain summons everyone around to see it. With the Captain in a good mood and the weather clear and quiet, it should be smooth sailing the rest of the way home.
As the ship approaches the Carribean, it's time to learn about a thing about how the ocean floor moves and ocean basins. The Captain mentioned something about Wilson and a plate tectonic cycle.
The Captain's Orders
Read the log book The Changing of the Ocean Basins to learn about sea-floor spreading and plate tectonics. You will need a calculator for this task and you may need external resources to help you answer some of the questions below. Make sure you make a note where you got your information. Answer the questions in complete sentences and complete the following tasks using the log book, a calculator, and your internet ready computer.
Objective -
Acquire and analyze data relating to the theory of Plate Tectonics and sea floor evolution.
Assess the development of the oceans and ocean basins throughout geologic time.
Questions -
Answer questions 1 through 5 with at least 3 complete sentences for each question. Be specific with your answers.
1. Which type of heat transfer is thought to occur in the mantle that helps fuel plate tectonic movement?
2. What happens to oceanic lithosphere over time, as it ages?
3. Why are continents so much older than the ocean basins?
4. Where in the world's oceans are the oldest rocks? How old are they?
5. Where does all new ocean crust form? Why?
6. Enter the terms in the left column into the appropiate boxs.
|
Terms
|
Oceanic Lithosphere
|
Continental Lithosphere
|
|
§ New rocks forming
§ Old rocks melting
§ Contains oldest rocks
§ Contains youngest rocks
§ Less than 250 million years
§ Older than 250 million years
§ High Density
§ Low Density
|
|
|
7. Label each diagram (A, B, and C) as either convergent plate boundary, divergent plate boundary, or transform plate boundary.
8. You find a 10,000,000 year old rock 2,500 km away from the nearest seafloor spreading center, how fast has the plate been moving since its formation? Give answer in cm/yr. (Hint: 1 km = 100,000 cm)
9. You find a rock 7,500 km away from the nearest seafloor spreading center. The plate is spreading at 5 cm/year, how old is the rock? Give answer in years. (Hint: 100,000 cm = 1 km)
10. You find a 2,400,000 year old rock formation on a plate that is spreading at 12 cm/year, how far is the rock formation from the spreading center? Give answer in kilometers. (Hint: 100,000 cm = 1 km).