Author Question: How does the process and rate seafloor spreading affect sea level? What will be an ideal ... (Read 40 times)

erika · **on:** Jul 15, 2018

How does the process and rate seafloor spreading affect sea level?

What will be an ideal response?

Question 2

Compare and contrast western and eastern North America during the Cenozoic Era.

What will be an ideal response?

shewald78 · **Reply #1 on:** Jul 15, 2018

Answer to Question 1

Answer: When new seafloor material forms, it is warm and has a lower density. As a result, the new, warm seafloor will sit higher on the mantle than old, cold seafloor. If a rift zone spreads quickly, that means there will be more low-density seafloor occupying the ocean basins. This displaces more seawater, causing shallow seas to transgress onto the continents.

Answer to Question 2

Answer: The western part of the continent was going through compression due to the Laramide Orogeny, uplifting the Rocky Mountains. After the subduction of the Farallon Plate ended (which had triggered this orogeny), the west went through extension, creating the Basin and Range Province. There were also the Tertiary Volcanic events at about the same time. The eastern part of the continent was fairly quiet, with erosion of the Appalachian Mountains and large-scale sediment deposition.