Situated in the Ódáðahraun

lava field A lava field, sometimes called a lava bed, is a large, mostly flat area of lava flows. Such features are generally composed of highly fluid basalt lava, and can extend for tens or hundreds of kilometers across the underlying terrain. Morp ...

, Trölladyngja () is the biggest of the

Iceland Iceland is a Nordic countries, Nordic island country between the Atlantic Ocean, North Atlantic and Arctic Oceans, on the Mid-Atlantic Ridge between North America and Europe. It is culturally and politically linked with Europe and is the regi ...

shield volcano A shield volcano is a type of volcano named for its low profile, resembling a shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more viscous lava ...

es, reaching a height of above

sea level Mean sea level (MSL, often shortened to sea level) is an mean, average surface level of one or more among Earth's coastal Body of water, bodies of water from which heights such as elevation may be measured. The global MSL is a type of vertical ...

, and rising almost above the surrounding

desert A desert is a landscape where little precipitation occurs and, consequently, living conditions create unique biomes and ecosystems. The lack of vegetation exposes the unprotected surface of the ground to denudation. About one-third of the la ...

and lava fields. It part of the

Bárðarbunga Bárðarbunga (, alternative name Veiðivötn), is an active and productive stratovolcano located under Vatnajökull in Vatnajökull National Park which is Iceland's most extensive glacier. The second highest mountain in Iceland, above sea le ...

volcanic system and has a volume of with some extensive lava flows to the north of Bárðarbunga. It is about in diameter and its inclination is 4 to 5° in the lower slopes, but 6 to 8° at higher elevations. Its oblong crater is about in length, broad, and about deep. Most of its

tholeiitic basalt The tholeiitic magma series () is one of two main magma series in subalkaline igneous rocks, the other being the calc-alkaline series. A magma series is a chemically distinct range of magma compositions that describes the evolution of a mafic ...

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

fields have flowed in a northerly direction, and the definite lava field has been dated at less than 4500 years old. Composition studies allow the separation of Trölladyngja lavas with their Bárðarbunga associations from other nearby older and younger Bárðarbunga basaltic lavas. This includes a Bárðarbunga volcanic system origin lava field branch, that possibly erupted from the fissure swarm south of Trölladyngja before 8000 years ago, that reached the valley of Bárðardalur, a distance of roughly and quite close to the northern Iceland sea coast. The shield volcano itself is situated north of latitude 64.7° where the strike direction of the fissure swarms formed in the last 10 million years and the 2014 dyke

intrusion In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...

from

towards the north have the orientation of the

Northern volcanic zone The Andean Volcanic Belt is a major volcanic belt along the Andean cordillera in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru. It is formed as a result of subduction of the Nazca plate and Antarctic plate underneath the South America ...

. The Bárðarbunga central volcano to the south is definitely in the Eastern volcanic zone. Reports of an eruption in 1961 at Trölladyngja are most likely attributed to nearby Askja Caldera, which erupted the same year. A potential confusion also exists geographically as in the distant past the name Trölladyngja had been used by some when writing about the Askja (Dynjufjöll, Dyngjufjall) volcanic system The volcano can now be definitely assigned to the

volcanic system. The volcano and its lava flows overlay older lava that is about 8000 years old.

References

{{DEFAULTSORT:Trolladyngja Mountains of Iceland Volcanoes of Iceland Holocene shield volcanoes Active volcanoes North Volcanic Zone of Iceland One-thousanders of Iceland Shield volcanoes of Iceland

See also

References