Helgrindur (, also known as Lýsuskarð, Lysuhóll or Lysukard) is a volcanic mountain range or massif in the middle of the

Snæfellsnes The Snæfellsnes () is a peninsula situated to the west of Borgarfjörður, in western Iceland. The peninsula has a volcanic origin having the Snæfellsnes volcanic belt down its centre, and the Snæfellsjökull volcano A volcano is com ...

peninsula that provides a backdrop to the port of

Grundarfjörður Grundarfjörður () is a town in the north of the Snæfellsnes peninsula in the west of Iceland. It is situated between a mountain range and the sea. The nearby mountain Kirkjufell forms a small peninsula. Overview The town received the right ...

. The volcano can be regarded as potentially active, with a risk of

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 ...

flows and much more rarely explosive

tephra Tephra is fragmental material produced by a Volcano, volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, ...

eruptions. The range with its prominent peaks, of Tröllkerling at in its south-east, Böðvarskúla at and Kaldnasaborgir (Kaldnasi) in its north-west at is popular with hikers or mountaineers.

Geography

The wide range, is in the middle of the

peninsula and thus divides the northern large bay of

Breiðafjörður Breiðafjörður (, ''wide fjord'') is a large shallow bay, about wide and long, to the west of Iceland. It separates the region of the Westfjords (Vestfirðir) from the Snæfellsnes peninsula to the south. Breiðafjörður is encircled by mo ...

from the southern bay of

Faxaflói Faxaflói (), sometimes Faxa Bay, Faxe Bay or Faxi Bay,Thorstein Thorsteinsson. 1930. ''Iceland, 1930: A Handbook Published on the Fortieth Anniversary of Landsbanki Íslands (National Bank of Iceland)''. Reykjavík: Ríkisprentsmidjan Gutenberg. ...

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 ...

is about to the range's south across Faxaflói. The weather systems in the two large bays are often quite different and the stormy winds across the range are quite notorious and can be heard sometimes at sea level.

Geology

The range is part of the

Snæfellsnes volcanic belt 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. ...

that extends from the prominent stratovolcano

Snæfellsjökull Snæfellsjökull (, ''snow-fell glacier'') is a 700,000-year-old glacier-capped stratovolcano in western Iceland. It is situated on the westernmost part of the Snæfellsnes peninsula. Sometimes it may be seen from the city of Reykjavík over Faxa ...

and its volcanic system, to the Helgrindur volcanic system and then on via Vatnafell, 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 ...

, to the

Ljósufjöll Ljósufjöll () is a fissure vent system and central volcano on the Snæfellsnes Peninsula in Iceland. The name derives from the central volcano and translates into English as "Mountains of the Light". Geography The volcanic system has a lengt ...

volcanic system in an east to west lineament. It is not currently known if Vatnafell is part of the Helgrindur volcanic system. The rocks tend to be alkaline

hyaloclastite Hyaloclastite is a volcanoclastic accumulation or breccia consisting of glass (from the Greek ''hyalus'') fragments (clasts) formed by quench fragmentation of lava flow surfaces during submarine or subglacial extrusion. It occurs as thin marg ...

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 ...

picrite basalt Picrite basalt or picrobasalt is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine. It is dark with yellow-green olivine phenocrysts (20-50%) and black to dark brown pyroxene, mostly augite. The olivine-rich ...

, however a central

rhyolite Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture (geology), texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained matri ...

formation is known. In total length there is a fissure swarm that extends from the south-east into the sea at its north-west. The most recent two eruptions were basaltic and must have occurred more than 1100 years ago. They are in the mid south portion of the volcanic system. The oldest rock from the system itself are 1.4 million years old, and have been emplaced over a 10 to 7 million year old extinct rift zone basaltic basement.

References

Icelandic sources

* * {{Volcanoes of Iceland, state=collapsed Mountains of Iceland Snæfellsnes Subglacial volcanoes of Iceland Volcanic systems of Iceland Central volcanoes of Iceland

Geography

Geology

See also

References

Icelandic sources