Formation of mesas with deep canyons in between

 
Flowing water can cut sharply through layers of rock. The area shown on the photo above is the Colorado River in Marble Canyon, about 20 miles downstream from Page, AZ. The view is to southeast. This photo was taken on April 12, 1966.

At this stage of erosion, the topography is mostly flat with a few incised rivers and streams. To cut such sharp canyons into he ground, special conditions are required - the climate must be arid so that little rain falls on the area itself, while a source of water outside the area must supply water that flows across. The area must be elevated relative to sea level for canyons to cut down. Rivers and streams are very rarely configured to cut downward below sea level so the base of this canyon is still well above sea level.

Over time, the relative proportion of canyon to flat area increase (flat area becomes less and canyon area widens). Depending on the size of the elevated areas that remain, these structures are called plateuas, mesas or buttes, depending on the size of the flat area from largest to smallest. However, these terms aren't defined very specifically so the buttes in one area might be larger than the mesas in another. These terms are often used to describe flat-topped structures made up of sediments, but that is not always true either. For example, Sutter Buttes in northern California are volcanic in origin. The term plateau is also used to refer to elevated parts of the seafloor which are often volcanic in origin.

Stuctures such as mesas are most often found in arid places where it rains very little, although water passes through rivers and streams. Where it rains more, the flat areas are destroyed by erosion, forming the hills and valleys of a more dendritic drainage pattern.