Question 1
What is the relationship of the dense oceanic crust that is produced at a divergent plate boundary to the convergence or collision of an oceanic plate and a continental plate, such as the western margin of South America in the diagram below?

Question 2
Below is a picture of water striking rocks at a coastline.

Describe which of Earth's "spheres" are interacting here, and some of the effects that may be caused by this interaction.