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185:(USGS) conducted a study over a three-year period monitoring granite cracks within the park's Valley. Data collected by Park Geologist Greg Stock, and USGS civil engineer Brian Collins using deformation and temperature gauges. They concluded that there is an outward expansion with the change in thermal temperature up to an inch. With prolonged movement, the cracks expand over time and create exfoliation.
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Engineers began construction on the dam in 1928 and placed the structure between two granite domes. In August 2014, the granite developed exfoliating joints and began to leak. The process was captured on video and is one of a couple ever to be caught on film. The lake was completely drained and the
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On the surface, if the granite is not jointed, or if it has few joints, then the exposed surface usually expands faster than the underlying granite. The surface layer, often a couple hundred feet thick, separates from the underlying granite along an
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that had and became visible with erosion. Gilbert presented his findings in a report and contributed significantly in what future generations would know as
Geomorphology.
152:. As the granite expands the outer, most shells become susceptible to weathering by water pressure, freeze/thaw cycles, and functioning vegetation is a process called
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may form to depths of 100 feet (30 m) feet or more. Concentric slabs/shells of rock begin to break loose, onion-like layers subparallel to the exterior called
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cost of reconstruction nine-hundred thousand dollars. In June 2016, the granite rock had to be closed off for a second time because of the continued exfoliation.
156:. The sheets of granite are large enough to shave off sharp edges on the granite's surface creating a dome shape. The overall activity creates exfoliation domes.
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Lutgens, Frederick K., and Edward J. Tarbuck. "Entire Book." Essentials Of
Geology. 9th ed. Upper Saddle River: Pearson Prentice Hall, 2006. 118-19. Print.
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Petersen, James F., Dorthy Sack, and Robert E. Gabler. "Pg. 292." Fundamentals of
Physical Geography. 1st ed. Belmont: Brooks/Cole, 2010. 292-93. Print.
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Gordon, Leslie C. "Hot Days Can
Trigger Yosemite Rockfalls." Hot Days Can Trigger Yosemite Rockfalls. USGS, 28 Mar. 2016. Web. 12 May 2017. <
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Schutter, Paul De. "Exfoliating Domes." OUGS Mainland Europe | The Open
University Geological Society: HOME. N.p., 2007. Web. 12 May 2017. <
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expansion in the joints during the winter accelerate the alteration process while the most unstable loose external layers are removed by
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layers of granite are gradually produced by the cyclic variations of temperature at the surface of the rock in a process also called
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of his generation. He was the only president of the
Geographic Society to receive the highest honor for geographic accomplishment;
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process, and are composed of different rock types. He observed that the mountain ranges in this area contained similarities in
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Hunter, Cathy. "Grove Karl
Gilbert, “A Captain Bold”." National Geographic Society. N.p., 13 Jan. 2016. Web. 12 May 2017. <
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Rockfall triggering by cyclic thermal stressing of exfoliation fractures : Nature
Geoscience : Nature Research
117:. The pressure is relieved when the granite is exposed at the surface, allowing it to expand towards the atmosphere.
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386:"Forming Yosemite's Famous Granite Domes." My Yosemite Park. N.p., 19 May 2015. Web. 12 May 2017. <
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Exfoliating granite spires, Granite Mts, May 2007 Exfoliating granite spires, Granite
Mountains
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Frank, Dave. USGS Geology and
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Mechanical Weathering is the breakdown of rocks into smaller fragments or pieces.
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McCaffrey, Tim. "History." Twain Harte Lake. N.p., 2016. Web. 12 May 2017. <
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are created in high-pressure environments and slowly solidify beneath the
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Granite skin peeling like an onion (desquamation) because of weathering
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Petersen, James F., Dorthy Sack, and Robert E. Gabler. "Pg. 292."
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occurs in granite exfoliation by changing the mineral composition.
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https://www.usgs.gov/news/hot-days-can-trigger-yosemite-rockfalls
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N. King Huber and Julie A. Roller, from the writings of
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553:. 1st ed. Belmont: Brooks/Cole, 2010. 292–93. Print.
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https://geomaps.wr.usgs.gov/parks/misc/gweaero.html
530:Exfoliating granite, Mount Kinabalu, Sabah, Borneo
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101:, or removal of overlying rocks resulting in
388:http://www.myyosemitepark.com/granite-domes/
140:to form a shell. As this continues, several
216:is considered one of the most influential
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181:are common and pose threats to visitors.
288:Discontinuity (geotechnical engineering)
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282:Characteristics of exfoliating granite
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551:Fundamentals of Physical Geography
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126:Enchanted Rock State Natural Area
23:Exfoliating slabs of granite, on
406:"Geologic Trips, Sierra Nevada"
183:United States Geological Survey
535:A photo from the Sierra Nevada
468:http://www.thlake.org/history/
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303:Geography of the Yosemite area
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509:External links and references
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202:Sierra Nevada Mountain Range.
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49:, or onion skin weathering (
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224:. Working his way down the
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540:One explanation on Youtube
430:http://www.ougseurope.org/
404:and other sources (1985).
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93:. Vertical compression of
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124:Exfoliating granite, at
276:Yosemite National Park
189:Infrastructure failure
179:Yosemite National Park
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29:Yosemite National Park
323:Spheroidal weathering
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85:Homogeneous granitic
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572:Geological processes
328:Chemical weathering
298:Foliation (geology)
200:located within the
154:physical weathering
39:Exfoliating granite
268:, also in Yosemite
214:Grove Karl Gilbert
209:Historic discovery
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177:. Rock Falls in
142:concentric shells
97:releases through
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293:Erosion surface
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250:Cannon Mountain
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198:Tuolumne County
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138:expansion joint
111:glacier retreat
107:tectonic uplift
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412:. Retrieved
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308:Granite dome
272:Royal Arches
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173:can trigger
169:Exfoliating
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115:mass wasting
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75:runoff water
73:assisted by
51:desquamation
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226:Great Basin
146:exfoliating
55:delaminated
47:exfoliation
45:undergoing
567:Weathering
561:Categories
373:0131497499
338:References
218:geologists
196:Dam is in
165:Rock falls
103:unloading.
95:overburden
414:5 January
266:Half Dome
150:fractures
25:Half Dome
262:in Texas
244:Examples
230:tectonic
175:rockfall
59:spalling
577:Granite
252:in the
160:Dangers
99:erosion
87:plutons
81:Geology
71:gravity
43:granite
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234:strata
113:, and
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470:>.
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432:>.
409:(PDF)
390:>.
318:Spall
238:magma
130:Texas
63:Frost
41:is a
416:2017
369:ISBN
171:rock
65:and
274:in
67:ice
33:USA
27:in
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