184:, where they are thought to indicate rock surfaces that are unglaciated or escaped more recent glaciations. In Sierra Nevada granitic rocks, these features have a characteristic shape such that they expand more rapidly in width than they grow in depth. One explanation for their conformation is because the most active environment for weathering is the zone of alternate wetting and drying along the margins of the pools that collect in the pits, the margins tend to deepen and enlarge until all points of the bottom are equally wet or dry at the same time, thus producing their characteristic shape. Panholes can expand from weathering and erosion but the main activity of how panholes expand is from biological weathering. At one time the belief was that the only agents involved with the expansion of panholes were physical weathering.
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152:. Panholes do not contain predators like fish or aquatic insects. The biofilm breaks down some of the siliceous minerals in the panhole for nutrients resulting in furthering the weathering the panhole. The organisms that live in the panholes have to tolerate rapid change in water temperature, pH, oxygen, carbon dioxide concentration, and ion concentration.
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is typically used for a smooth, bowl-shaped or cylindrical hollow, generally deeper than wide, found developed in the rocky bed of a stream. This type of feature is created by the grinding action either of a stone or stones or of coarse sediment whirled around and kept in motion by eddies or the
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Panholes are erosional or destructional features that are developed in a variety of climatic environments and in a wide range of rock types. These shallow basins, or closed depressions, are quite commonly well developed in surfaces of
110:. Diameters are rarely greater than 6 ft (1.8 m). Some panholes were at one time thought to be man-made because their roundness was so perfect they were argued not be natural and must have been shaped by humans.
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137:. Panholes range in size from a few centimeters to many meters in diameter. The cavities can be shallow or more than 15 meters (49 ft) deep, containing hundreds of liters of water. The
129:, and Moab. Panholes are capable of collecting water when it rains, freezing over when the weather gets cold, dry out in hotter weather, and can even contain some species of bacteria,
145:, in particular, implies a depression capable of holding water in arid areas, forming an important water resource for Aboriginal people that needed to be carefully maintained.
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Clyde
Warhaftig, attributed on page p. 63 in Huber, N. King. 1989. The geological story of Yosemite National Park. U.S. Geological Survey Bulletin 1595.
106:. They are generally characterized by flat bottoms and sometimes by overhanging sides. The initial form may be a closed hollow created by a patch of
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to describe a naturally formed rock hole as well as its retained rainwater. The term "gnamma hole" is also widely used, but is incorrect, being a
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Bacterial
Communities and their Influence on the Formation and Development of Potholes in Sandstone Surfaces of the Semi-Arid Colorado Plateau
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Géomorphologie: Relief, Processus, Environnement, Articles sous presse, Varia, mis en ligne le 08 janvier 2018, consulté le 01 juillet 2018.
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Within the panholes is a varied eco-system that contains bacteria such as cyanobacteria, fungi, and algae which can be referred to as
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Matthes, Francois E. 1930. Geologic
History of the Yosemite Valley. U.S. Geological Survey Professional Paper 160
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is a depression or basin eroded into flat or gently sloping cohesive rock. Similar terms for this feature are
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Huber, N. King. 1989. The geological story of
Yosemite National Park. U.S. Geological Survey Bulletin 1595.
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In
Australia, the terms "gnamma" and "rock hole" (or "rockhole") are used. Gnamma is an anglicization of a
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University of
Western Ontario - Electronic Thesis and Dissertation Repository. Paper 543.
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370:"SA students take to the bush to connect with land and Indigenous culture"
121:. A few well-known panholes are found developed in sandstone surfaces in
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427:(5th ed.). Alexandria, Virginia, American Geological Institute. 800 pp.
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Depression or basin eroded into flat or gently sloping cohesive rock
491:"What are “Potholes” and how are organisms able to live in them?."
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Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds., 2011.
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In the Sierra Nevada, California these features were termed
532:"Geomorphology of pit gnammas in southwestern Australia"
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Geomorphology of pit gnammas in southwestern
Australia
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Utah
Geological Survey. N.p., n.d. Web. 9 Oct 2013.
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316:Twidale, C.R., and Bourne, J.A., 2018.
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76:Some authors refer to panholes also as
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270:, Yosemite National Park, California
172:, Yosemite National Park, California
113:Panholes are most commonly found in
378:Australian Broadcasting Corporation
460:10.1016/B978-0-12-374739-6.00068-3
368:Jonscher, Samantha (3 June 2018).
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319:Rock basins (gnammas) revisited.
292:Stone Mountain (North Carolina)
1:
448:Tafoni and Other Rock Basins
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127:Capitol Reef National Park
452:Treatise on Geomorphology
343:Western Australian Museum
262:Canyonlands National Park
123:Canyonlands National Park
408:Hughes, Kebbi A., 2012.
280:Shenandoah National Park
274:Navajo National Monument
446:Paradise, T. R., 2013 '
243:Hiltaba Nature Reserve
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198:Hiltaba Nature Reserve
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572:Depressions (geology)
530:Timms, B. V. (2013).
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139:Australian Aboriginal
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470:Timms, B.V., 2013.
425:Glossary of Geology
256:Forbes State Forest
216:word, used by that
182:François E. Matthes
115:desert environments
489:Davis, Jim, 2013.
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214:Nyoongar language
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188:Terminology
93:Description
84:, the term
561:Categories
350:5 November
299:References
282:, Virginia
220:people of
218:Aboriginal
102:rocks and
51:rock holes
567:Landforms
545:9 January
383:9 January
288:, Georgia
276:, Arizona
237:Australia
232:Locations
226:tautology
208:Australia
104:sandstone
374:ABC News
100:granitic
78:potholes
18:Rockhole
541:(96): 7
150:biofilm
131:lichens
86:pothole
43:panhole
36:Corsica
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346:. 2017
264:, Utah
156:Origin
143:gnamma
65:) and
47:gnamma
535:(PDF)
450:' in
141:term
108:humus
547:2022
429:ISBN
385:2022
352:2021
71:pits
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180:by
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