Geology & The Ice Age
Traces of the immense forces that shaped the landscape
Introduction to the Region's Geology
The present-day landscape around Burträsk is a direct and impressive result of the last major ice age, the Weichselian glaciation, which ended about 10,000 years ago. The enormous ice masses acted like a giant plane, reshaping the land and leaving behind the characteristic lakes, hills, and river valleys we see today.
Welcome to the geological open-air sauna of Västerbotten! Although "sauna" might be the wrong word considering there was a kilometer-thick layer of ice here just 10,000 years ago. Imagine a gigantic, ice-cold bulldozer giving all of Scandinavia a close shave. That was the Weichselian glaciation! This frosty wrecking ball of nature didn't just move a few pebbles around; it performed epic landscape therapy. It carved deep bathtubs (our modern-day lakes) into the solid rock and casually scattered all the debris around as pretty moraine hills.
But wait, there's more! The landscape here is basically recovering from a chronic posture problem. Because the ice was unimaginably heavy, it literally dented the Earth's crust – much like sitting on a very soft mattress. Ever since the ice retreated, the Earth has been breathing a sigh of relief and the land is rising. We call this "post-glacial rebound". The coast of Västerbotten shoots up by almost a centimeter every single year! So, if you just stand here long enough, you'll literally get a little bit closer to the sun.
And the ground beneath our feet? That's the famous Fennoscandian Shield. A true ancient bedrock, over a billion years old and so tough that even diamond drills would chip their teeth on it. This extremely hard granite and gneiss ensures that our water stays crystal clear and doesn't just seep away into the soil. So, the next time you trip over a boulder in the forest, don't get mad. Tip your hat to it! Because that stone probably traveled on the Ice-Express and has seen more of the world than both of us combined.
Basic Geological Knowledge
Fact Box: Geology
- Formative Era: Weichselian Glaciation
- Bedrock: Fennoscandian Shield (ancient bedrock)
- Special Feature: Post-glacial rebound continues to this day
What primarily shaped the landscape?
The movement of giant glaciers. They carved out deep basins that later filled with meltwater to form today's lakes. The rock material they carried was deposited elsewhere.
What are the moraines that you see everywhere?
A moraine is the debris transported and deposited by a glacier. The gentle hills in the landscape are often such moraine ridges, formed at the edge or under the ice.
What is the Fennoscandian Shield?
This is the extremely old bedrock that forms the foundation of all of Scandinavia. It consists of very hard rocks like granite and gneiss and is over a billion years old.
What does "post-glacial rebound" mean?
During the Ice Age, the kilometer-thick ice pressed the land down. Since the ice melted, the land has been slowly "springing" back up. This process, which continues today, is about 8-9 mm per year on the coast of Västerbotten.
Why are the soils here often so sandy or rocky?
The soils consist mainly of the material left behind by the glaciers. These are often sandy or gravelly moraines, which are not very fertile but are typical for the vegetation of the taiga.
Where can I best see the traces of the Ice Age?
Everywhere! The elongated shape of the lakes, the rounded, ice-polished rocks (roches moutonnées) on the shores, and the countless glacial erratics (large, single boulders) in the forests are all direct witnesses of the Ice Age.