Mesa: Definition, Formation and the Famous Types

Photo of Mesa: Definition, Formation and the Famous Types

A mesa is a Spanish word which means table, the word mesa describes a hill or a mountain with a flat top, this table-like land is characterised by a flat surface, wide and steep walls and it is wider than its height, hence it can be called a table hill or table mountain. These Table Mountains are found at different places in the world and are called by different names such as mesa, butte, tuya, amba or it is simply called Table Mountain. At the top of these table mountains, various plants and animals species exist which are not common in any other places in the world.

Mesa definition

A mesa with steep sides
A mesa with steep sides

 

A mesa is a flat tabular landform with steep walls. A mesa looks like the top of a table, or may resemble a butte, but it is larger than a butte in size and less extensive than a plateau, mesas are found commonly in the arid and semi-arid environments; hence, very few are found in the tropics. Mesas are commonly found in drier regions where rock layers appearhorizontal in shape. For instance, they are found in South-western United State, California, Dakotas, Texas, Utah and in sprain. Other parts of the World that mesas can be found are Plateau State Nigeria (West Africa), South Africa and India Australia, among other parts of the World. The top layer of a mesa is called the cap rock, it is hardened and can withstand erosion, but beneath the cap rock are horizontal layers of softer sedimentary rock, which to some extent are not resistant to erosion. This less resistant rock layers are made upofshale, they are softer in nature and can easily weathered and erode over time.

How are mesas formed?

Mesas are formed by weathering and erosion activities; when flowing water on the top of a hill or ground water moves through permeable overlying layers, it gradually washes smaller and softer parts of the rock away; the hard and durablerocks are left standing on their own, looking taller than their physical surroundings which is thecap rock. Such resistant rocks types include quartzite, chert, limestone, sill, sandstone and conglomerate, while shale is the less resistant rock type. The base of a mesa is often gently sloped, contrasting with the vertical sides leading down from the top. Rock materials that have been eroded from the sides are carried downward and they form the sloping base. However, the more resistant layers are what form the cliffs, or stair steps, while the less resistant layers form the gentle slopes or benches between the cliffs.

Mesas are mostly found in dry regions of the world where there are horizontal rocks that have been lifted by tectonic process. Mesa distinctive shapes are formed as a result of different rock layers and this different rock layers give rise to rugged sides of mesas called the cliff and bench topography which are broken into a staircase patterns.

Famous mesas

Picture showing Grand mesa
Picture showing Grand mesa

 

Grand mesa is considered as the largest and the famous mesa in the world, it is located in western Colorado in the Southwest United States. This mesa is said to be the most resistant rock types and it has an area of about 1,300km2 (500 square miles) and stretches out to 64 km (40 miles). However, this mesa rises to about 1,800m (6,000 feet) above the surrounding river valleys, including the Grand valley and to the west reaching an elevation of about 3,400m (11,000 ft.), with a maximum elevation of 3,454m (11,333 ft.) atCrater peak.

Grand mesa lies between the Colorado River and Gunnison River and extends its tributaries to the south. Largely a smaller tributary of Colorado -Plateau Creek, drains the north side of the mesa while the west side is emptied into Kannah Creek. Over millions of years, erosion has carved out the sides of the mesa and overhangs and alcoves have developed where sections of softer sandstone layers have broken away.
In 1505, a European man named Antonio de Saldanha was the first to land on this high mountain and he named it Table Mountain. However, a cable car is now used to carry passengers to the top of the mountain with views overlooking Cape Town and Table Bay to the north, and the Atlantic seaboard to the west and south.

Other famous mesas of the world are:

  • Mount Conner (Artilla) – it is located Central Australia, It is in the southwest corner of the Northern Territory.
  • Heroubreio- it is located on the Highlands ofIceland.
  • Mount Roraima- it is located in Venezuela.
  • Debre Damo- it is located in Northern Ethiopia.
  • Brown Bluff it is located in the northern tip of the Antarctic Peninsula.
  • Canyonlands- it is located in eastern Utah
  • Auyantepui (Devils mountain) – it is found in Venezuela.
  • KukenanIt is located near the most famous tepui Mount Roraima.
  • Mount Asgard -It is located in Auyuittuq National Park in Baffin Island.

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