Colorado, United States 37°45′23″N106°56′03″W / 37.75639°N 106.93417°W / 37.75639; -106.93417
VEI
8
The Fish Canyon Tuff is the large volcanic ash flow or ignimbrite deposit resulting from one of the largest known explosive eruptions on Earth, estimated at 1,200 cu mi (5,000 km3).[1] (see List of largest volcanic eruptions). The Fish Canyon Tuff eruption was centred at the La Garita Caldera in southwest Colorado; the caldera itself would have formed by collapse, as a result of the eruption. Studies of the tuff show that it all belongs to one eruption due to its uniform bulk-chemical composition (SiO2=bulk 67.5–68.5% (dacite), matrix 75–76% (rhyolite) and consistent phenocryst content (35–50%) and mineralogical composition (plagioclase, sanidine, quartz, biotite, hornblende, sphene, apatite, zircon, Fe-Ti oxides are the primary phenocrysts). This tuff and eruption is part of the larger San Juan volcanic field[2] and the Oligocene Southern Rocky Mountain ignimbrite flare-up.[3]
The Fish Canyon Tuff eruption occurred around 28 Million years ago. Sanidine crystals from the Fish Canyon Tuff (FCTs) are used as a reference mineral in 40Ar-39Ar dating, and the current 'astronomically calibrated' age for the FCTs is 28.175 Ma.[4]
^Lipman, Peter W. (December 7, 2006). "Geologic map of the central San Juan caldera cluster, southwestern Colorado" – via pubs.er.usgs.gov.
^Lake, Ethan T.; Farmer, G. Lang (May 15, 2015). "Oligo-Miocene mafic intrusions of the San Juan Volcanic Field, southwestern Colorado, and their relationship to voluminous, caldera-forming magmas". Geochimica et Cosmochimica Acta. 157: 86–108. doi:10.1016/j.gca.2015.02.020 – via ScienceDirect.
^Phillips, D.; Matchan, E. L.; Dalton, H.; Kuiper, K. F. (May 20, 2022). "Revised astronomically calibrated 40Ar/39Ar ages for the Fish Canyon Tuff sanidine – Closing the interlaboratory gap". Chemical Geology. 597: 120815. doi:10.1016/j.chemgeo.2022.120815. S2CID 247563968 – via ScienceDirect.
The FishCanyonTuff is the large volcanic ash flow or ignimbrite deposit resulting from one of the largest known explosive eruptions on Earth, estimated...
significant portion of what is now Colorado. The deposit, known as the FishCanyonTuff, covered at least 11,000 sq mi (28,000 km2). Its average thickness...
Pyroclastic flows may also be of dacitic composition as is the case with the FishCanyonTuff of La Garita Caldera. Dacitic magma is formed by the subduction of...
Pyroclastic materials are the primary product, typically in the form of tuff. Eruptions the size of that at Lake Toba 74,000 years ago, at least 2,800...
(Possibly as high as a VEI 9), 5,000 cubic kilometers (1,200 cu mi) of FishCanyonTuff was blasted out in a single, major eruption about 27.8 million years...
Precise K–Ar, 40Ar/39Ar, Rb–Sr and U/Pb mineral ages from the 27.5 Ma FishCanyonTuff reference standard, Chemical Geology 175(3–4), pp 653–671. Mason, B...
Naomi E. Matthews (2014). "The magnitude and impact of the Youngest Toba Tuff super-eruption". Frontiers in Earth Science. 2: 16. Bibcode:2014FrEaS...2...
largely intermediate composition lavas and breccias, together with ash flow tuffs reflecting differentiation of the original magma. The precaldera intermediate...
volcanic field, Colorado; VEI 8; more than 5,000 km3 (1,200 cu mi) of FishCanyonTuff was blasted out in a major single eruption about 27.8 Ma. San Juan...
eruption with a magnitude of 9.2 . It has been dated to 27.51 Ma ago. This tuff and eruption is part of the larger San Juan volcanic field and Mid-Tertiary...
supervolcano and its sidekicks: A 100 ka eruptive chronology of the FishCanyonTuff and associated units of the La Garita magmatic system, Colorado, USA"...
board used by Mark "Occy" Occhilupo in 1984. Rusty released the surf film TUFF (2015), which starred Noa Deane, Josh Kerr, and Dylan Goodale. Surfer magazine...
Yellowstone River at 308 feet (94 m). Three deep canyons are located in the park, cut through the volcanic tuff of the Yellowstone Plateau by rivers over the...
The geology of the Zion and Kolob canyons area includes nine known exposed formations, all visible in Zion National Park in the U.S. state of Utah. Together...
Naomi E. Matthews (2014). "The magnitude and impact of the Youngest Toba Tuff super-eruption". Frontiers in Earth Science. 2: 16. Bibcode:2014FrEaS...2...
very large eruption released hot ash that later cooled to form the Bishop tuff that is common to the area. The eruption emptied the magma chamber under...
camping area as well that accommodates tent camping only. Its sheer cliffs of tuff and basalt are ideal for rock climbing of all difficulty levels. Smith Rock...
Complex. Prior to the 1960s, geologists inferred the Vishnu and Farmington Canyon gneiss and schist as Archean in age, but subsequent research indicated a...
metamorphic rocks found at Cabo Carvoeiro or Baleal, as well as in the Papoa tuff–breccia, similar to those recognized in the archipelago, confirms this hypothesis...
include Cochetopa Park Tuff, Nelson Mountain Tuff, Carpenter Ridge Tuff, and FishCanyonTuff. The volcanic ash that formed these tuffs came from Oligocene...
South of the springs, the rocks of the canyon are Tertiary volcanics, mostly dark-gray basalt and yellow-gray tuff. Fossil Springs, the source of about...
(/ˌhɑːnəˈuːmə/; Hawaiian: [həˈnɔumə]) is a marine embayment formed within a tuff ring and located along the southeast coast of the Island of Oʻahu in the...
Hong Kong; although the High Island Reservoir is not basalt but rhyolitic tuff, rich in potash feldspar and quartz phenocrysts. In India, columnars are...
volcanic rock known as tuff, formed during cataclysmic eruptions around 35 million years ago. The rocks of the eroded canyon contain iron and manganese...
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