Ingólfsfjall () is a

tuya A tuya is a flat-topped, steep-sided volcano formed when lava erupts through a thick glacier or ice sheet. They are rare worldwide, being confined to regions which were covered by glaciers and had active volcanism during the same period. As lava ...

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 ...

in the vicinity of

Hveragerði Hveragerði (, "hot-spring yard") is a town and municipality in the south of Iceland, 45 km east of Reykjavík on Iceland's main ringroad, Route 1. The river Varmá runs through the town. With an area of 9 square kilometers, Hveragerði ...

Name

The name is derived from Iceland's official first settler, Ingólfur Arnarson. The Medieval

Landnámabók (, "Book of Settlements"), often shortened to , is a medieval Icelandic written work which describes in considerable detail the settlement () of Iceland by the Norse in the 9th and 10th centuries CE. is divided into five parts and ov ...

says that he passed here his third winter in Iceland after his arrival from

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...

with his clan, and before his slaves found the columns of his high seat and he went to the region of

Reykjavík Reykjavík is the Capital city, capital and largest city in Iceland. It is located in southwestern Iceland on the southern shore of Faxaflói, the Faxaflói Bay. With a latitude of 64°08′ N, the city is List of northernmost items, the worl ...

to settle there. The source also states that the chief was buried within the small mound on top of Ingólfsfjall.

Geology

Ingólfsfjall consists mostly of

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

and

palagonite Palagonite is an alteration product from the interaction of water with volcanic glass of chemical composition similar to basalt. Palagonite can also result from the interaction between water and basalt melt. The water flashes to steam on contact ...

and has its origin in

subglacial eruption Subglacial eruptions, those of ice-covered volcanoes, result in the interaction of magma with ice and snow, leading to meltwater formation, jökulhlaups, and lahars. Flooding associated with meltwater is a significant hazard in some volcanic a ...

s which turned in the end subaerial and produced some lava at its top.Ari Trausti Guðmundsson, Pétur Þorleifsson: Íslensk Fjöll. Gönguleiðir á 151 tind. Reykjavík 2004, p.140 A quarry at the southern side of the mountain near the National Road no. 1 (Hringvegur/Suðurlandsvegur) shows some of these layers which consist mostly of

igneous Igneous rock ( ), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava. The magma can be derived from partial ...

as well as

sedimentary rocks Sedimentary rocks are types of rock formed by the cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or deposited at Earth's surface. Sedim ...

. The oldest of these rocks have an age of around 800 000 years. The main volcanic bulk is about 400-500 000 years old. By the end of the last Ice Age (

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

), the mountain formed a small peninsula, because the sea level had risen after many glaciers had thawed. The uplift of the land itself followed not until much later.

The 2008 earthquake

The mountain is situated in a tectonically very active zone, the

South Iceland Seismic Zone The geological deformation of Iceland is the way that the rocks of the island of Iceland are changing due to tectonic forces. The geological deformation help to explain the location of earthquakes, volcanoes, fissures, and the shape of the island. ...

. In 2008, the

hypocentre A hypocenter or hypocentre (), also called ground zero or surface zero, is the point on the Earth's surface directly below a nuclear explosion, meteor air burst, or other mid-air explosion. In seismology, the hypocenter of an earthquake is its p ...

of a 6.3

earthquake An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they ...

was situated just under Ingólfsfjall so that many

landslides Landslides, also known as landslips, rockslips or rockslides, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, mudflows, shallow or deep-seated slope failures and debris flows. Landslide ...

happened at its flanks.

Silfurberg

On the southwestern side of the mountain in the direction of the Hringvegur, there is a small

truncated spur A truncated spur is a spur, which is a ridge that descends towards a valley floor or coastline from a higher elevation, that ends in an inverted-V face and was produced by the erosional truncation of the spur by the action of either streams, wa ...

. It is interesting, because the rocks have a color different of all the other layers of Ingólfsfjall. This color reminds of silver, and so it was called Silfurberg. In reality, this is palagonite which has been hydrothermally altered by a basaltic dike.Snæbjörn Guðmundsson: Vegvísir um jarðfræði Íslands. Reykjavík 2015, p. 257-258

References

External links

Daníel Einarsson: Uppruni og myndun Ingólfsfjalls. Jarðlagaeiningar og myndanir í Ingólfsfjalli syðra. Jarðvísindadeild Háskóli Íslands. (2012)
(in Icelandic) {{Coord, 63.9821, -21.0388, format=dms, display=title, region:IS_type:mountain Mountains of Iceland Tuyas of Iceland West Volcanic Zone of Iceland Volcanoes of Iceland South Iceland Seismic Zone