mesa

As noted by geologist Kirk Bryan in 1922, mesas "...stand distinctly above the surrounding country, as a table stands above the floor upon which it rests".{{cite journal |last=Bryan |first=K. |date=1922 |title=Erosion and Sedimentation in the Papago Country, Arizona |journal=US Geological Survey Bulletin |issue=730 |pages=19–90 }} It is from this appearance that the term mesa was adopted from the Spanish word mesa, meaning "table".Migoń, P., 2004a. Mesa. In: Goudie, A.S. (Ed.), Encyclopedia of Geomorphology. Routledge, London, pp. 668. {{ISBN|9780415272988}}

A mesa is similar to, but has a more extensive summit area than, a butte. There is no agreed size limit that separates mesas from either buttes or plateaus. For example, the flat-topped mountains which are known as mesas in the Cockburn Range of North Western Australia have areas as large as {{convert|350|km2|mi2|abbr=on}}. In contrast, flat topped hills with areas as small as {{convert|0.1|km2|mi2|abbr=on}} in the Elbe Sandstone Mountains, Germany, are described as mesas.Duszyński, F., Migoń, P. and Strzelecki, M.C., 2019. Escarpment retreat in sedimentary tablelands and cuesta landscapes–Landforms, mechanisms and patterns. Earth-Science Reviews,' no. 102890. doi.org/10.1016/j.earscirev.2019.102890Neuendorf, Klaus K.E. Mehl, James P., Jr. Jackson, Julia A.. (2011). Glossary of Geology (5th Edition). American Geosciences Institute. {{ISBN|9781680151787}}

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.

In the English-language geomorphic and geologic literature, other terms for mesa have also been used. For example, in the Roraima region of Venezuela, the traditional name, tepui, from the local Pomón language, and the term table mountains have been used to describe local flat-topped mountains.Briceño, H.O. and Schubert, C., 1990. Geomorphology of the Gran Sabana, Guayana Shield, southeastern Venezuela. Geomorphology, 3(2), pp.125-141.

Doerr, S.H., 1999. Karst-like landforms and hydrology in quartzites of the Venezuelan Guyana shield: Pseudokarst or" real" karst?. Zeitschrift fur Geomorphologie, 43(1), pp.1-17. Similar landforms in Australia are known as tablehills, table-top hills, tent hills, or jump ups (jump-ups).Jack, R.L., 1915. The Geology and prospects of the Region to the South of the Musgrave Ranges, and the Geology of the Western Portion of the Great Australian Artesian Basin. Geol. Survey South Australia Bulletin 5, pp. 72.{{Citation|title=Macquarie dictionary : Australia's national dictionary online|url=https://trove.nla.gov.au/work/18855142|publication-date=2021|publisher=Macquarie Library|access-date=11 March 2021}}{{Cite web|date=2012|title=Land Zones of Queensland|url=https://environment.des.qld.gov.au/?a=89669|access-date=11 March 2021|publisher=Queensland Government|pages=62–63}} The German term Tafelberg has also been used in the English scientific literature in the past.King, L.C., 1942. South African Scenery. A Textbook of Geomorphology. Oliver and Boyd, Edinburgh, London (340 pp.).

Mesas form by weathering and erosion of horizontally layered rocks that have been uplifted by tectonic activity. Variations in the ability of different types of rock to resist weathering and erosion cause the weaker types of rocks to be eroded away, leaving the more resistant types of rocks topographically higher than their surroundings.{{cite book |last= Easterbrook |first= Don J. |title= Surface Processes and Landforms |year= 1999 |publisher= Prentice Hall |location= Upper Saddle River, NJ |isbn= 9780138609580}} This process is called differential erosion. The most resistant rock types include sandstone, conglomerate, quartzite, basalt, chert, limestone, lava flows and sills. Lava flows and sills, in particular, are very resistant to weathering and erosion, and often form the flat top, or caprock, of a mesa. The less resistant rock layers are mainly made up of shale, a softer rock that weathers and erodes more easily.

The differences in strength of various rock layers are what give mesas their distinctive shape. Less resistant rocks are eroded away on the surface into valleys, where they collect water drainage from the surrounding area, while the more resistant layers are left standing out. A large area of very resistant rock, such as a sill, may shield the layers below it from erosion while the softer rock surrounding it is eroded into valleys, thus forming a caprock.

Differences in rock type also reflect on the sides of a mesa, as instead of smooth slopes, the sides are broken into a staircase pattern called "cliff-and-bench topography". The more resistant layers form the cliffs, or stairsteps, while the less resistant layers form gentle slopes, or benches, between the cliffs. Cliffs retreat and are eventually cut off from the main cliff, or plateau, by basal sapping. When the cliff edge does not retreat uniformly but instead is indented by headward eroding streams, a section can be cut off from the main cliff, forming a mesa.

Basal sapping occurs as water flowing around the rock layers of the mesa erodes the underlying soft shale layers, either as surface runoff from the mesa top or from groundwater moving through permeable overlying layers, which leads to slumping and flowage of the shale.{{cite book |last1=Choreley |first1=Richard J. |author2=Stanley A. Schumm |author3=David E. Sugden|author-link3=David E. Sugden |title= Geomorphology |year= 1985 |publisher= Methuen |location= New York }} As the underlying shale erodes away, it can no longer support the overlying cliff layers, which collapse and retreat. When the caprock has caved away to the point where only little remains, it is known as a butte.

• Cockburn Range, Western Australia{{cite book |last1=Burbridge |first1=Andrew |last2=Mckenzie |first2=NL |last3=Kenneally |first3=Kevin F |title=Nature Conservation Reserves in the Kimberley, Western Australia |date=1991 |publisher=Department of Conservation and Land Management |isbn=9780646033747 |url=https://books.google.com/books?id=r3eWCMlsvSQC |access-date=4 July 2021}}
• Mount Conner, Northern Territory{{cite book |title=Report |date=1966 |publisher=The Department |url=https://books.google.com/books?id=lkc7AAAAIAAJ}}

• Děčínský Sněžník, Ústí nad Labem Region

• Mont Aiguille, Auvergne-Rhône-Alpes

• Königstein, Saxony[https://books.google.com/books?id=HV4DAAAAQBAJ Kindred by Choice Germans and American Indians Since 1800, Glenn H Penny, 2013]
• Lilienstein, Saxony[https://www.nationalpark-saechsische-schweiz.de/besucherinformation/ausflugsziele/lilienstein-ein-tafelberg-mit-symbolcharakter/?lang=en Lilienstein – a mesa with a symbolic character]
• Papststein, Saxony
• Pfaffenstein, Saxony{{cite web |last1=Jancewicz |first1=Kacper |title=Morphological diversity of mesas in Elbsandsteingebirg |url=https://www.researchgate.net/figure/Morphological-diversity-of-mesas-in-Elbsandsteingebirge-on-three-representative_fig2_342350433 |website=ResearchGate |access-date=4 July 2021}}
• Quirl, Saxony

• Several near Owk mandal, Andhra Pradesh

• Amadiya, Kurdistan Region

• Kings Mountain, County SligoJournal of Earth Sciences Royal Dublin Society. (1980). Ireland: The Society.
• Knocknarea, County Sligo
• Knocknashee, County Sligo

• Masada, Southern District{{cite web |title=Masada - Definition, History, Siege & Facts |url=https://www.britannica.com/place/Masada |website=Encyclopedia Britannica |access-date=4 July 2021}}
• Har Qatum

• Monte Santo, Sardinia

• Szczeliniec Wielki, Lower Silesian Voivodeship

• Castle Folds, Cumbria{{cite book |date=2009 |publisher=Zalozoba ZRC |isbn=9789612541613 |page=286 |url=https://books.google.com/books?id=9dlAixcXztYC |access-date=4 July 2021|title=Karst Rock Features. Karren sculpturing: Karren sculpturing }}
• Cross Fell, Cumbria[https://books.google.com/books?id=U_pEAAAAYAAJ Lakeland - The Wildlife of Cumbria, Derek A Ratcliffe]
• Goldsborough Carr, County DurhamReading, H. G. (1954) The stratigraphy and structure of the syncline of stainmore, Durham theses,

Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/9349/

• Higger Tor, South Yorkshire{{cite journal |journal=University of Peshawar - Bulletin of the Centre of Excellence in Geology |volume=7-8 |page=3 |url=https://books.google.com/books?id=EEI7AAAAIAAJ |title=Bulletin of the Centre of Excellence in Geology |date=1975 }}
• Ingleborough, North Yorkshire
• Pen-y-ghent, North Yorkshire{{cite book |last1=Wood |first1=Harold |last2=Preece |first2=Dorothy |title=Modern Geography ...: The British Isles |date=1948 |url=https://books.google.com/books?id=EZXXAAAAMAAJ |access-date=9 July 2022}}
• Shacklesborough, County Durham

• Healabhal Mhòr, Isle of Skye{{cite news |last1=Reid |first1=T.R. |title=A Lord's Leaky Roof vs. a Changing Scotland |url=https://www.washingtonpost.com/archive/politics/2000/11/02/a-lords-leaky-roof-vs-a-changing-scotland/c7756bf0-9996-4162-9c1f-c112c6efc9ec/ |access-date=10 August 2022 |newspaper=The Washington Post |date=2 November 2000}}

Many but not all American mesas lie within the Basin and Range Province.

• Anderson Mesa
• Black Mesa (Apache-Navajo Counties)
• Black Mesa (Navajo County)
• Black Mesa (Warm Springs)
• Black Mountain
• Cummings Mesa
• First Mesa
• Horseshoe Mesa
• Indian Mesa
• Second Mesa

• Mount Magazine

• Redonda Mesa

• Battlement Mesa
• Grand Mesa - largest flat-topped mountain in the world.[http://nationalgeographic.org/encyclopedia/mesa/ National Geographic Encyclopedia (2016)]
• Green Mountain
• Log Hill Mesa
• North Table Mountain
• Raton Mesa

• Mormon Mesa
• Pahute Mesa

• Black Mesa
• Mesa de Maya

• Floating Mesa{{cite web |title=Floating Mesa, Bushland, Texas |url=https://www.atlasobscura.com/places/floating-mesa |website=Atlas Obscura |access-date=19 October 2021}}
• Llano Estacado

• Checkerboard Mesa
• Crazy Quilt Mesa
• Hurricane Mesa
• Sams Mesa
• Smith Mesa
• South Caineville Mesa
• Thompson Mesa
• Wildcat Mesa
• Wingate Mesa

• Gibraltar Rock
• Grandad Bluff
• Mile Bluff
• Quincy Bluff
• Rattlesnake Mound

A transitional zone on Mars, known as fretted terrain, lies between highly cratered highlands and less cratered lowlands. The younger lowland exhibits steep walled mesas and knobs. The mesa and knobs are separated by flat lying lowlands. They are thought to form from ice-facilitated mass wasting processes from ground or atmospheric sources. The mesas and knobs decrease in size with increasing distance from the highland escarpment. The relief of the mesas range from nearly {{Convert|2|km|mi|abbr=on|sp=us}} to {{Convert|100|m|ft|abbr=on|sp=us}} depending on the distance they are from the escarpment.Baker, David M. Morphological Analyses of Mesas and Knobs in the Northwest Fretted Terrain of Mars; Constraints on the Presence and Distribution of Ice-Facilitated Mass-Wasting. Ed. Alexander K. Stewart and James W. Head. Vol. 40. Issue 2. pp. 72. United States: Geological Society of America (GSA) : Boulder, CO, United States, 2008.

{{div col|colwidth=22em}}

• {{annotated link|Amba (landform)|Amba}}
• {{annotated link|Archipelago}}
• {{annotated link|Butte}}
• {{annotated link|Dissected plateau}}
• {{annotated link|Mensa (geology)|Mensa}}
• {{annotated link|Mesa Verde National Park}}
• {{annotated link|Nor'Wester Mountains}} – Group of mountains immediately south of Thunder Bay, Ontario, Canada
• {{annotated link|Pingdingshan}} – Chinese city named after a local mesa
• {{annotated link|Potrero (landform)|Potrero}}
• {{annotated link|Table (landform)|Table hill}}
• {{annotated link|Table Mountain}}
• {{annotated link|Tepui}}
• {{annotated link|Tundra}}
• {{annotated link|Tuya}}

{{div col end}}

{{Commons category|Mesas}}

{{Wiktionary}}

{{Reflist}}

{{Authority control}}

Category:Erosion landforms

Category:Geography terminology

Category:Slope landforms