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.
The process of mitosis in an animal cell.
Simplified diagram of the fractional distillation process
Confirming an Extinction-Level Impact Site
Five step nursing process
Communication throughout the nursing process
Acute Stress, Glucocorticoid Level, Synaptic Plasticity, and Learning