Editing Rock shelter

{{Short description|Shallow cave-like opening at the base of a bluff or cliff}}
{{Redirect|Abri}}
{{About|the geological formation|landslip protection|Rock shed}}
{{About||rock face with a slope of more than 90°|Overhang (rock formation)}}
{{more sources|date=October 2022}}
[[File:Rockhouse Cliffs Rockshelter.jpg |thumb|Rockhouse Cliffs Rock Shelter]]
[[Image:Rock shelter Papula.jpg|thumb|Rock shelter in the [[Little Carpathians]]]]

A '''rock shelter''' (also '''rockhouse''', '''crepuscular cave''', '''bluff shelter''', or '''abri''') is a shallow [[cave]]-like opening at the base of a bluff or [[cliff]]. In contrast to [[solutional cave]]s ([[karst]]), which are often many miles long or wide, rock shelters are almost always modest in size and extent.

==Formation==
Rock shelters form because a [[Rock (geology)|rock]] stratum such as sandstone that is resistant to [[erosion]] and [[weathering]] has formed a cliff or bluff, but a softer stratum, more subject to erosion and weathering, lies just below the resistant stratum, and thus undercuts the cliff.

In arid areas, [[wind]] erosion ([[Aeolian erosion]]) can be an important factor in rockhouse formation. In most humid areas, the most important factor in rockhouse formation is [[frost weathering|frost spalling]], where the softer, more porous rock underneath is pushed off, tiny pieces at a time, by frost expansion from water frozen in the pores. Erosion from moving water is seldom a significant factor.

Many rock shelters are found under [[waterfalls]].

<gallery caption="Rock shelter formation types" perrow="3">
File:Rock shelter formation by frost weathering.svg|By [[frost weathering]]
File:Rock shelter formation by karst gallery cutting.svg|By cutting a [[karst]] gallery
File:Rock shelter formation by river erosion.svg|By [[river erosion]]
</gallery>

==Human habitat==
[[File:Shepherds' rock shelter, Lahaul.jpg|thumb|Shepherds' rock shelter in [[Lahaul]], India]]
[[File: Excavation at Paleolithic site of Bawa Yawan, Zagros, Iran 2017.jpg|thumb|left|upright|Bawa Yawan rockshelter, sieving of excavated deposits at a Paleolithic site in Iranian Zagros, April 2017]]
[[Image: turtleheadcave.jpg|upright|thumb|Rock shelter at<br>[[Strouds Run State Park]]]]
Rock shelters are often important [[archaeology|archaeologically]]. Because rock shelters form natural shelters from the weather, prehistoric humans often used them as living-places, and left behind debris, tools, and other [[Artifact (archaeology)|artifacts]]. In mountainous areas the shelters can also be important for [[Mountaineering|mountaineers]].<ref>{{Cite journal |last=Straus |first=Lawrence Guy |date=1990 |title=Underground Archaeology: Perspectives on Caves and Rockshelters |url=https://www.jstor.org/stable/20170209 |journal=Archaeological Method and Theory |volume=2 |pages=255–304 |issn=1043-1691}}</ref>

[[Transhumant]] nomads, people who move with their livestock - often from lower permanent winter residences in the valleys to higher summer pastures - frequently build semi-permanent camps, often of rocks.

In western [[Connecticut]] and eastern [[New York (state)|New York]], many rock shelters are known by the [[colloquialism]] "leatherman caves",<ref>[http://www.ctmuseumquest.com/?page_id=6343 CT Museum: Leatherman Caves]</ref> as they were inhabited by the [[Leatherman (vagabond)|Leatherman]] over three decades in the late 19th century.

==Unique vegetation==
The [[Minuartia cumberlandensis|Cumberland stitchwort]] (''Minuartia cumberlandensis'') is an endangered species of plant which is found only in rock shelters in Kentucky and Tennessee.<ref>[http://www.centerforplantconservation.org/collection/cpc_viewprofile.asp?CPCNum=13821 Center for Plant Conservation] {{webarchive|url=https://web.archive.org/web/20101215120249/http://centerforplantconservation.org/Collection/CPC_ViewProfile.asp?CPCNum=13821 |date=2010-12-15 }}</ref>

==See also==
* {{annotated link|Bhimbetka rock shelters}}
* {{annotated link|Fincha Habera, Ethiopia|Fincha Habera Rock Shelter}}
* {{annotated link|Gatecliff Rockshelter}}
* {{annotated link|Kinlock Shelter}}
* {{annotated link|Mesa Verde National Park}}
* {{annotated link|Overhang (architecture)}}
* {{annotated link|Roc-aux-Sorciers}}
* {{annotated link|Rock shed}}
* {{annotated link|Shelter Rock (North Hills, New York)|Shelter Rock}}
* {{annotated link|Simple dolmen}}
* {{annotated link|Walnut Canyon National Monument}}

==References==
{{Reflist}}

== Further reading ==
* Acosta ''et al''., 2018. "[http://boletinsgm.igeolcu.unam.mx/bsgm/index.php/component/content/article/368-sitio/articulos/cuarta-epoca/7001/1857-7001-1-acosta Climate change and peopling of the Neotropics during the Pleistocene-Holocene transition]". Boletín de la Sociedad Geológica Mexicana. 

==External links==
* {{Commons category inline|Rock shelters}}

{{Prehistoric technology| state=expanded}}
{{Subterranea}}

{{Authority control}}

[[Category:Rock shelters| ]]