What does the Wilson cycle describe?

• A. The lifecycle of ocean basins from rifting to spreading to subduction and collision.
• B. The formation of metamorphic rocks.
• C. The cycle of erosion and deposition in deserts.
• D. The cycle of groundwater contamination.

Answer: (A)

The main idea here is how ocean basins form and disappear as Earth's tectonic plates move. The Wilson cycle maps the long-term lifecycle of an ocean basin: continental rifting breaks apart a continent to start a new ocean, seafloor spreading widens that ocean basin, and eventually subduction consumes the basin as oceanic crust sinks beneath another plate, bringing continents together in collision and mountain-building. Over very long timescales this can lead to the formation of a supercontinent, which may later rift apart again to begin a new cycle.

This isn’t about how metamorphic rocks form, nor about desert erosion processes, nor about groundwater contamination, so those choices don’t describe the cycle.