Skjaldbreiður (, "broad shield") is an

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 ...

ic lava shield formed in a huge and quite protracted eruption series from about roughly 9,500 years ago. The extensive

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 ...

s which were produced by this eruption, flowed southwards, and formed the basin of Þingvallavatn, Iceland's largest lake, and

Þingvellir Þingvellir (, anglicised as ThingvellirThe spelling ''Pingvellir'' is sometimes seen, although the letter "p" is unrelated to the letter thorn (letter), "þ" (thorn), which is pronounced as "th".) was the site of the Althing, Alþing, the annual ...

, the "Parliament Plains" where the Icelandic national assembly, the

Alþing The (; ), anglicised as Althingi or Althing, is the supreme national parliament of Iceland. It is the oldest surviving parliament in the world. The Althing was founded in 930 at (' thing fields' or 'assembly fields'), about east of what la ...

was founded in 930. The volcano summit is at , and its

crater A crater is a landform consisting of a hole or depression (geology), depression on a planetary surface, usually caused either by an object hitting the surface, or by geological activity on the planet. A crater has classically been described ...

measures roughly in diameter. The Skjaldbreiður lava shield covers with a volume of about . and is sometimes considered as a separate southern part of the Oddnýjarhnjúkur-Langjökull volcanic system which it is usually classified as being within. In this context its most recent eruption would be 3600 years ago, and the earliest eruption after the last ice age 10,200 years ago. There are at least three lava units deposited between 6000 and 9000 years BP, Straddling the

Mid-Atlantic Ridge The Mid-Atlantic Ridge is a mid-ocean ridge (a Divergent boundary, divergent or constructive Plate tectonics, plate boundary) located along the floor of the Atlantic Ocean, and part of the List of longest mountain chains on Earth, longest mountai ...

, the lava fields from Skjaldbreiður have been torn and twisted over the millennia, forming a multitude of fissures and rifts inside the Þingvellir National Park, the best known of which are Silfra, Almannagjá , Hrafnagjá and Flosagjá .

Gallery

File:Skjaldbreidur Panorama.jpg, Skjaldbreiður crater in snow.

References

Sources

* * {{DEFAULTSORT:Skjaldbreidur Mountains of Iceland Shield volcanoes of Iceland Dormant volcanoes West Volcanic Zone of Iceland Lava fields Þingvellir One-thousanders of Iceland