A BRIEF INTRODUCTION TO THE HISTORICAL FORMATION OF ICELAND IN THE ATLANTIC OCEAN

This section is rather technical concerning geological science. If you would like to skip this and move towards illustrated virtual tours through Iceland you can switch directly to these pages: The North South tour through the middle of Iceland. The North South tour along the west coast (under construction) and the North South tour along the east coast (under construction).

In the middle of the Atlantic Ocean between Europe/Africa and the America's runs a majot cleft in the earth's crust. From this tear, volcanic activities push the eastern oceanic plate (European/African side) and the western oceanic plate (the American side) away from each other. This means that the continents Europe/Africa vs the Americans drift away in opposite directions. And Iceland is to blame... Of coarse this is a little joke, however there is a deep truth about it. In order to understand this the geological concept of hot-spots needs to be explained.

Mantle plumes: The liquid/solid part of earth consists of three main sections. The surface regions consist of rock material (or sediments/weathered materials on rocks, like agricultural soils). This section is called the crust. About 80% of the earth's surface consists of water (often deep oceans). So, where is the crust there? It is a rather thin layer under the oceans but is much thicker under the continents. Below the crust lies the mantle - a region of liquefied rock/stone material due to the very high temperatures. The third section being the core is a Nickel-Iron bulb in the very centre of the earth. Temperatures here are so extreme that they compare to the sun's temperature. Hot bodies need to release their heat. One would think that the heat is released equally along the mantle/crust border. This however, is not the case. Rather, flows in the mantle region lead to specific places where heat rises upwards and elsewhere downwards. The area's where mantle flows are moving toward the crust are called mantle plumes. The two best known hot spots are Hawaii and Iceland. There is a major difference though. Hawaii lies on a moving (drifting) plate. New volcanic isles are formed as the plate moves over the mantle plume. Iceland lies right on top of the cleft of the Atlantic Ocean. In fact there is a theory that the mantle plume - once developed under what is now Iceland - lead to a major crack in the earth's crust causing the break-up of Europe/Africa and the America's and as a result the formation of the (Atlantic) Ocean. This is the little joke that Iceland is to blame for the rift between Europe/Africa and the America's . The figure below illustrates the heat circulation in the mantle and the position of Iceland over a mantle plume.

What this figure shows is that the mid-Atlantic rift should run right through the middle of Iceland. And that is so. The mantle plume is the red hot spot under Iceland. Geologically the youngest region of Iceland is in the middle where most volcanic activities occur. Moving east or west form the centre the landscapes (rocks) become older. However, it is not quite that simple: in the south there is a major side branch from the main rift zone towards Reykjavik in the south-west (Reykjavik in Icelandic means "hot springs at a sea bay"). Another westwards side branch of the main volcanic transect is the feature of the Snæfelsness peninsula leading towards the strato volcano Snæfelsness. This volcano has in geological history only just become dormant. This volcano became the inspiration for the 19th century SF-story "Journey to the Centre of the Earth" by Jules Verne. However the two side branches from the main active zone, one can conclude that the oldest regions of Iceland are along the western and eastern coast while the youngest areas are found in the middle of the island.