reservoir
reservoir
reservoir
reservoir
reservoir
A crater.
A crater.
No
Deposition by erosion , could fill a depression , the same erosion creates depressions.
lakes
craters from hits by meteors.
Ocean Basin
a sulcus is a depression or a groove found on the surface of an organ or tissue,as on the surface of the brain separating adjacent convultion. While a gyrus is one of the prominent rounded elevations between the sulci or grooves on the surface of the hemispheres of the brain.