The answer is subduction. In locations around the world, ocean crust subducts, or slides under, other pieces of Earth's crust. The boundary where the two plates meet is called a convergent boundary.

"This shows that the margin is not passive anymore but is now being reactivated, i.e. a new convergent plate boundary is forming," Duarte said. "If you were looking for an embryonic subduction ...

For more on divergent boundary, go to The Sea Floor Spread. Also known as subduction boundary, a convergent boundary occurs where one plate slides under another as the two are pushed together.

The deep subduction of continental crust is traditionally ... (4) Can we constrain the geometrical and geological structure of paleo-convergent continental margins and then precisely reveal ...

"This shows that the margin is not passive anymore but is now being reactivated, i.e. a new convergent plate boundary is forming," Duarte said. "If you were looking for an embryonic subduction ...