A mesa is an isolated geological landform characterized by a flat top and steep escarpments on all sides. These elevations stand out distinctly above the surrounding plains, creating a plateau-like appearance.
The structure of a mesa is formed by layers of soft sedimentary rocks, such as shales, which are covered by a resistant layer of harder rock like sandstone or limestone. This upper layer acts as a caprock that protects the flat summit from erosion. In some instances, the caprock may also consist of eroded duricrust or dissected lava flows.