in a way, they are both part of the process called sea floor spreading. the trench is where the ocean floor is subducted and the rift valley is where the molten material comes up and cools.
This iis a trench.Also ocean basin is the deepest part of the ocean.
mariana's trench/ the valley of death in Ireland
great rift valley
glimpse
ocan
trench
trench
a plateau
This is known as a trench in a subduction zone.
marina trench
That is a subduction trench.