A cut block of trachyandesite lava from a volcano in Auvergne, France, used as building stone, forming part of the walls of Clermont-Ferrand Cathedral, FranceTrachyandesite is field S3 in the TAS diagram
Trachyandesite is an extrusive igneous rock with a composition between trachyte and andesite. It has little or no free quartz, but is dominated by sodic plagioclase and alkali feldspar. It is formed from the cooling of lava enriched in alkali metals and with an intermediate content of silica.[1][2]
The term trachyandesite had begun to fall into disfavor by 1985[1] but was revived to describe extrusive igneous rocks falling into the S3 field of the TAS classification. These are divided into sodium-rich benmoreite and potassium-rich latite.[3]
Trachyandesitic magma can produce explosive Plinian eruptions, such as happened at Tambora in 1815.[4] The Eyjafjallajökull 2010 eruption (VEI-4[5]), which disrupted European and transatlantic air travel from 14–18 October 2010,[6] for some time was dominated by trachyandesite.[7]
^ abMcBirney, Alexander R. (1984). Igneous petrology. San Francisco, Calif.: Freeman, Cooper. p. 503. ISBN 0198578105.
^Neuendorf, Klaus K.E.; Mehl, James P. Jr.; Jackson, Julia A. (2011). Glossary of geology (Fifth revised ed.). American Geological Institute. ISBN 9781680151787.
^Le Bas, M. J.; Streckeisen, A. L. (September 1991). "The IUGS systematics of igneous rocks". Journal of the Geological Society. 148 (5): 825–833. Bibcode:1991JGSoc.148..825L. doi:10.1144/gsjgs.148.5.0825. S2CID 28548230.
^Self, S.; Gertisser, R.; Thordarson, T.; Rampino, M. R.; Wolff, J. A. (2004). "Magma volume, volatile emissions, and stratospheric aerosols from the 1815 eruption of Tambora" (PDF). Geophysical Research Letters. 31 (20): L20608. Bibcode:2004GeoRL..3120608S. doi:10.1029/2004GL020925. hdl:20.500.11820/6925218f-d09e-4f9d-9f2e-3ab8419b223f. S2CID 56290102.
^Eyjafjallajokull. Eruptive history. Global Volcanism Program. Retrieved 26 August 2020.
^Woodhouse, M. J.; Hogg, A. J.; Phillips, J. C.; Sparks, R. S. J. (January 2013). "Interaction between volcanic plumes and wind during the 2010 Eyjafjallajökull eruption, Iceland: VOLCANIC PLUMES AND WIND" (PDF). Journal of Geophysical Research: Solid Earth. 118 (1): 92–109. doi:10.1029/2012JB009592.
^Donovan, Amy R; Oppenheimer, Clive (March 2011). "The 2010 Eyjafjallajökull eruption and the reconstruction of geography: Commentary". The Geographical Journal. 177 (1): 4–11. doi:10.1111/j.1475-4959.2010.00379.x.
Trachyandesite is an extrusive igneous rock with a composition between trachyte and andesite. It has little or no free quartz, but is dominated by sodic...
targets – Basaltic lava with a flowing, often ropy appearance Basaltic trachyandesite – Naming system for volcanic rocksPages displaying short descriptions...
Trachybasalt. S2 (Basaltic trachyandesite)—*Sodic and potassic variants are Mugearite and Shoshonite. S3 (Trachyandesite—*Sodic and potassic variants...
rock. More specifically, it is a potassium-rich variety of basaltic trachyandesite, composed of olivine, augite and plagioclase phenocrysts in a groundmass...
example in the intrusive dioritic pluton of El Teniente, Chile and in trachyandesite pumice erupted by El Chichón volcano, Mexico. The name anhydrite was...
mafic compositions. Typical intermediate rocks include andesite and trachyandesite among volcanic rocks and diorite and granodiorite among plutonic rocks...
alkaline rocks atypical for oceanic islands, ranging from basalt through trachyandesite and trachyte to rhyolite. Ascension has a hot desert climate (BWh, according...
various rock types are distinguished in the Kiruna porphyry such as trachyandesite lava and quartz-bearing porphyry of rhyolitic composition. These two...
Pozzolana containing significantly less volcanic glass, such as a trachyandesite from Volvic (France) with only 25 wt% are less reactive. Apart from...
basalt-trachybasalt-trachyandesite volcanoes (Ngorongoro also contains trachydacite) and the 1.6-1.5 Ma Oldeani basalt-trachyandesite volcano. The highlands...
fields, such as the trachyandesite field, are further classified by the ratio of potassium to sodium (so that potassic trachyandesites are latites and sodic...
sediments and volcanic rocks. The volcanics consist of rhyolite, basalt, trachyandesite, and trachyrhyolite. Uranium ore bodies are found in the Dornod, consisting...
trachyandesite was interpreted as lacustrine, likely the result of ponding against the volcanic flows. The high relative abundance of trachyandesite and...
olivine phenocrysts. This first cone is lengthened to the north by the trachyandesite tuff ring which caused its obstruction. These projections are dark and...
is the tephra of Deception Island, which is of trachyte and basaltic trachyandesite, richer in potassium and sodium. Quaternary volcanic products of the...
million years ago, above an accumulation of several layers of pyroclastic trachyandesite. The summit is accessible from the ski resort of Super Lioran by a cable...
deposited dacite, rhyolite and ignimbrite, as well as trachyte and trachyandesite. This trend towards the production of more felsic, viscous lavas could...
drying in the sun in many places. The island consists primarily of trachyandesite rock. A major explosive eruption about 9,350 years ago reached a Volcanic...
an estimated VEI of 7. An estimated 41 km3 (10 cu mi) of pyroclastic trachyandesite were ejected, weighing about 10 billion tonnes. This left a caldera...
descended over steep slopes. Tambora has produced trachybasalt and trachyandesite rocks which are rich in potassium. The volcanics contain phenocrysts...
have calderas. Ngorongoro Volcano (2.5–1.9 Ma) is primarily basaltic trachyandesite. The caldera is fed by the Munge and Oljoro Nyuki Rivers, while the...
Cantal massif, Puy Chavaroche is composed of alternating layers of trachyandesite and volcanic breccias. Puy Chavaroche can be reached on foot from the...
KILAUEA), James St. John, OSU-Newark, Geology 'Unusual Newer Volcanics trachyandesite cones in the Gisborne-Woodend and Kyneton-Trentham areas' Clark, V....
Huechulafquen. This cone has three craters. A tephra layer of black trachyandesite has been linked to Huanquihue and is dated 4028-4212 BP. Varve count...
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