Rock shelter

"Abri" redirects here. For other uses, see Abri (disambiguation).

This article is about the geological formation. For landslip protection, see Rock shed.

For rock face with a slope of more than 90°, see Overhang (rock formation).

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 caves (karst), which are often many miles long or wide, rock shelters are almost always modest in size and extent.

Rockhouse Cliffs Rock Shelter

Rock shelter in the Little Carpathians

Formation

Rock shelters form because a 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 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.

• Rock shelter formation types
• 
  By frost weathering
• 
  By cutting a karst gallery
• 
  By river erosion

Human habitat

Shepherds' rock shelter in Lahaul, India

Bawa Yawan rockshelter, sieving of excavated deposits at a Paleolithic site in Iranian Zagros, April 2017

Rock shelter at
Strouds Run State Park

Rock shelters are often important 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 artifacts. In mountainous areas the shelters can also be important for mountaineers.

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, many rock shelters are known by the colloquialism "leatherman caves", as they were inhabited by the Leatherman over three decades in the late 19th century.

Unique vegetation

The Cumberland stitchwort (Minuartia cumberlandensis) is an endangered species of plant which is found only in rock shelters in Kentucky and Tennessee.

See also

• Bhimbetka rock shelters – 30,000+ years old archaeological World Heritage site in Madhya Pradesh, India
• Fincha Habera Rock Shelter – Middle Stone Age archeological site in southern Ethiopia
• Gatecliff Rockshelter – Archaeological site in the Great Basin area of the western United States
• Kinlock Shelter – Rock shelter and Native American cultural site in Alabama
• Mesa Verde National Park – U.S. national park in Colorado
• Overhang (architecture) – Architectural Roofing Feature
• Roc-aux-Sorciers – Cave and archaeological site with prehistoric art in France
• Rock shed – Road protection structure
• Shelter Rock – Landmarked rock shelter in Nassau County, New York, USAPages displaying short descriptions of redirect targets
• Simple dolmen – Early form of dolmen or megalithic tomb
• Walnut Canyon National Monument – Protected area in Coconino County, Arizona

Further reading

• Acosta et al., 2018. "Climate change and peopling of the Neotropics during the Pleistocene-Holocene transition". Boletín de la Sociedad Geológica Mexicana.

External links

• Media related to Rock shelters at Wikimedia Commons