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.
- 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.
Answer questions 1 through 5 with at least 3 complete sentences for each question. Be specific with your answers.
- Which type of heat transfer is thought to occur in the mantle that helps fuel plate tectonic movement?
- What happens to oceanic lithosphere over time, as it ages?
- Why are continents so much older than the ocean basins?
- Where in the world’s oceans are the oldest rocks? How old are they?
- Where does all new ocean crust form? Why?
- Enter the terms in the left column into the appropiate boxs. TermsOceanic LithosphereContinental 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
- Label each diagram (A, B, and C) as either convergent plate boundary, divergent plate boundary, or transform plate boundary.
- 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)
- 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)
- 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)