Geologic stratigraphic column of strata exposed in and near the Grand Canyon
Of the many unconformities (gaps) observed in geological strata, the term Great Unconformity is frequently applied to either the unconformity observed by James Hutton in 1787 at Siccar Point in Scotland,[1][failed verification] or that observed by John Wesley Powell in the Grand Canyon in 1869.[2] Both instances are exceptional examples of where the contacts between sedimentary strata and either sedimentary or crystalline strata of greatly different ages, origins, and structure represent periods of geologic time sufficiently long to raise great mountains and then erode them away.
^Rance, H (1999) Historical Geology: The Present is the Key to the Past. Archived 3 December 2008 at the Wayback Machine QCC Press, New York
^Merten, G (2005) Geology in the American Southwest: New Processes, New Theories In MF Anderson, ed., A Gathering of Grand Canyon Historians. Proceedings of the Inaugural Grand Canyon History Symposium, January 2002. Grand Canyon Association, Grand Canyon, Arizona.
and 26 Related for: Great Unconformity information
the many unconformities (gaps) observed in geological strata, the term GreatUnconformity is frequently applied to either the unconformity observed by...
The significance of angular unconformity (see below) was shown by James Hutton, who found examples of Hutton's Unconformity at Jedburgh in 1787 and at...
Karlstrom, and C Dehler (1999) Grand Canyon Supergroup Six Unconformities Make One GreatUnconformity A Record of Supercontinent Assembly and Disassembly. Boatman's...
is about 1 billion years (1,000 million years), and is named the GreatUnconformity. Besides its occurrence in the Grand Canyon, it is also found west...
Unconformity lies at the base of the Sixtymile Formation. This unconformity is either an angular unconformity truncating tilted strata of the Grand Canyon Supergroup...
Karlstrom, and C. Dehler (1999) Grand Canyon Supergroup Six Unconformities Make One GreatUnconformity A Record of Supercontinent Assembly and Disassembly. Boatman's...
known as the "GreatUnconformity" which has been interpreted as a large scale erosional event in the basement rock unit. This unconformity is used to correlate...
have been provided by the widespread erosion that produced Powell's GreatUnconformity. An increase of calcium may also have been caused by erosion of the...
period of long-running terrestrial erosion which produced by the GreatUnconformity, from 1.1 billion to 510 million years ago. Twelve to 24 kilometers...
forming over this first uplift, resulting in a local expression of the GreatUnconformity. At about 500–300 million years ago, the region began to sink and...
Karlstrom, and C Dehler (1998) Grand Canyon Supergroup Six Unconformities Make One GreatUnconformity A Record of Supercontinent Assembly and Disassembly Archived...
called unconformities by geologists. The GreatUnconformity is one of the best examples of an exposed nonconformity, which is a type of unconformity that...
geological record. This gap is part of a more generalized gap called the GreatUnconformity. About 510 million years ago, the granite was again subject to deposition...
Limestone formed in the sea was metamorphosed by mafic intrusions. The GreatUnconformity is a famous gap in the stratigraphic record, as Arizona experienced...
Group is a prominent angular unconformity, which is part of the GreatUnconformity. The surface of this angular unconformity truncates dipping strata comprising...
portal World portal Europa Gaia hypothesis Global catastrophic risks GreatUnconformity Interglacial and stadial periods Lake Nyos Pu, J.P. (2016). "Dodging...
as, glacial deposits, significant continental erosion called the GreatUnconformity, and sedimentary rocks called cap carbonates that form after a deglaciation...
Karlstrom, and C. Dehler (1999) Grand Canyon Supergroup Six Unconformities Make One GreatUnconformity A Record of Supercontinent Assembly and Disassembly. Boatman's...
coast of Scotland. It is famous in the history of geology for Hutton's Unconformity found in 1788, which James Hutton regarded as conclusive proof of his...
Karlstrom, and C. Dehler (1999) Grand Canyon Supergroup Six Unconformities Make One GreatUnconformity A Record of Supercontinent Assembly and Disassembly. Boatman's...
underlying Precambrian rocks forming the GreatUnconformity. This contact is either an angular unconformity truncating tilted strata of the Grand Canyon...
p. 7. Gannett (1905), p. 176. "Ouray's History Timeline: From the GreatUnconformity to the Utes and Miners". Ouray, Colorado. Archived from the original...
horizontal Tapeats Sandstone (the Tonto Platform, and called the GreatUnconformity). "Ochoa Point – 4,761' AZ". Lists of John. Retrieved January 22,...
Geologists, Tulsa, Oklahoma. Rowland, S. (nda) Frenchman Mountain and the GreatUnconformity. Department of Geoscience, University of Nevada, Las Vegas, Nevada...
formation contributes to new appreciation of the time of formation of The GreatUnconformity in Colorado. She is currently working on Ice sheet erosional Interaction...
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