Mesa

A mesa is an isolated, flat-topped elevation, ridge or hill, which is bounded from all sides by steep escarpments and stands distinctly above a surrounding plain.

The caprock can consist of either sedimentary rocks such as sandstone and limestone; dissected lava flows; or a deeply eroded duricrust.

For example, the flat-topped mountains which are known as mesas in the Cockburn Range of North Western Australia have areas as large as 350 km2 (140 sq mi).

In contrast, flat topped hills with areas as small as 0.1 km2 (0.039 sq mi) in the Elbe Sandstone Mountains, Germany, are described as mesas.

[1][2][3] Less strictly, a very broad, flat-topped, usually isolated hill or mountain of moderate height bounded on at least one side by a steep cliff or slope and representing an erosion remnant also have been called mesas.

[10] Mesas form by weathering and erosion of horizontally layered rocks that have been uplifted by tectonic activity.

The most resistant rock types include sandstone, conglomerate, quartzite, basalt, chert, limestone, lava flows and sills.

[11] Lava flows and sills, in particular, are very resistant to weathering and erosion, and often form the flat top, or caprock, of a mesa.