Scandinavian Peninsula - Geology

Geology

The Scandinavian Peninsula occupies part of the Baltic Shield, a stable and large crust segment formed of very old, crystalline metamorphic rocks. Most of the soil covering this substrate was scraped by glaciers during the Ice Ages of antiquity, especially in northern Scandinavia, where the Baltic Shield is closest to the surface of the land. As a consequence of this scouring, the elevation of the land, and the cool-to-cold climate, a relatively small percentage of its land is arable.

The glaciation during the Ice Ages also deepened many of the river valleys, which were invaded by the sea when the ice melted, creating the noteworthy fjords of Norway. In the southern part of the peninsula, the glaciers deposited vast numbers of terminal moraines, configuring a very chaotic landscape. These terminal moraines covered all of what is now Denmark.

Although the Baltic Shield is mostly geologically stable and hence resistant to the influences of other neighboring tectonic formations, the weight of nearly four kilometers of ice during the Ice Ages caused all of the Scandinavian terrain to sink. When the ice sheet disappeared, the shield rose again, a tendency that continues to this day at a rate of about one meter per century. Conversely, the southern part has tended to sink to compensate, causing flooding of the Low Countries and Denmark.

The crystalline substrate of the land and absence of soil in many places have exposed mineral deposits of metal ores, such as those of iron, copper, nickel, zinc, silver, and gold. The very most valuable of these have been the deposits of iron ore in northwestern Sweden. In the 19th century these deposits prompted the building of a railroad from northwestern Sweden to the Norwegian seaport of Narvik so that the iron ore could be exported by ship to places like southern Sweden, Germany, Great Britain, and Belgium for smelting into iron and steel. This railroad is in a region of Norway and Sweden that otherwise do not have any railroads because of the very rugged terrain, mountains, and fjords of that part of Scandinavia.