The origin of the Faroe Islands

Posted by ShrikantModh | 7:44 AM | Faroe Islands | 0 comments »

Name: The origin of the Faroe Islands
Date of Issue: 25 May 2009
Country: Faroe Islands
Denominations: DKK 60,00

Continental Drift
Millions of years ago the continents of the Earth were joined in a super continent called Pangaea. About 200-135 million years ago, Pangaea split into two parts, Laurasia in the north and Gondwana in the south. About 60 million years ago the seafloor had started to spread between Canada and Greenland along the Labrador Ridge, and between Greenland and the Faroe-Rockall plateau along the Mid Atlantic Ridge. This was the start of an era of intense volcanic activity along the entire continental shelf, and volcanoes appeared all the way from Greenland, on the Faroe-Rockall Plateau and along the west coast of Scotland down to the south eastern corner of Ireland. Great parts of the Faroe-Rockall Plateau as well as parts of the British Plateau sank below sea level.

Origin of the Faroe Islands – The Lower Basalt Formation
On the Faroe Plateau there were intense eruptions from gigantic volcanic fissures with shorter or longer breaks. The lava settled in layers and became the lower basalt formation. These layers are thick, the average height is about 20 metres and the total height of the lower basalt formation is about 900 metres.

The Coal Bearing Formation
When the volcanoes, which created the lower basalt formation, stopped, there was a long period without volcanic activity. The top of the formation crumbled and eroded in the subtropical climate, vegetation started to spread and eventually turned into regular forests. The coal bearing formation with charred tree trunks, roots, leaves and other organic remains, and the thin sedimentary layers show that the break in the volcanic activity lasted for a long time.

Volcanic Ash
The long period of growth, which created the coal bearing formation, came to an abrupt end in an explosive pyroclastic eruption. Lava bombs, volcanic tuff and ashes spread over the landscape and charred and covered the forest. There was very little lava in this first explosion, and a thick and irregular layer of reddish tuff covers the coal bearing formation.

The Middle Basalt Formation
As a direct continuation of the pyroclastic eruption, a period of constant volcanic activity started. There were only very short or none breaks between the lava flows in this period. These eruptions created the middle basalt formation, with layers much thinner than the lower and upper formations. Most layers are thinner than 1-2 metres. Put together, these layers form the thickest formation, appr. 1350 metres.

The Upper Basalt Formation
Again there was a break or at least a change in the volcanic activity. When the volcanoes became active again, the eruptions were not as frequent as when the middle basalt formation was formed, but with shorter or longer breaks in between. The lava flows from this period became the upper basalt formation with layers about 10 metres thick in average. The upper basalt formation is appr. 675 metres in total.

Intrusions
The base below the massive plateau broke in certain places because of the enormous weight. This caused cracks up through the basalt layers all over the plateau. Lava penetrated these cracks from below, but did no longer reach up on the plateau itself. These phenomena are called intrusions, i.e. vertical or inclined dikes - irregular discordant intrusions in the tuff layers called stock - and finally sills, which have penetrated horizontally between the middle and upper basalt formations.

Depressions, Ice Ages and Erosion
The volcanoes on the Faroe Plateau became inactive millions of years ago. Since then, external forces have eroded and shaped the formations into the landscape we know today. The base below the plateau gave in for the weight, and the land area has an easterly dip. Heat, frost, wind and water eroded the rock. In valleys and fiords and sounds, which during the Ice Age still were above sea level, mighty glaciers carved the rock on their way towards the sea and created a rugged landscape. Surf and strong currents took their share of the land. Left in the middle of the North Atlantic Ocean, we find the archipelago known as the Faroe Islands, a scarred monument of mighty forces of nature in the ancient past. And the geological history of the Faroe Islands will probably not have a happy ending. The erosion will continue and sometime in a distant future, the last cliff will plunge into the sea and the billows dance over former glory.