Bedrock and soil
Kuopio scenery is dominated mainly by extensive waterways and forest-covered hills which sometimes rise to 300 m above sea level. The highest hills like Kinahmi (314 m) and Välimäki (same height) can be found in Nilsiä’s quartzite belt. In Maaninka a substantial ridge fringe area exists and because of that, the surface level is flatter than other areas of Kuopio.
The bedrock is mainly composed of different gneiss. Wear resistant quartzites are in hilly regions. The quartzite ridge on the western side of Syväri can be compared to the northern end of the North Karelian forested hills. Kuopio’s highest hills can also be found in this area. The type of alkaline rock that increases soil fertility can be found in the soil especially in the belt from Nilsiä to Kuopionniemi’s southern area. Kuopio's most valuable deciduous woodlands are also located in the same zone.
The most common soil type is moraine. The finest soil materials like silt and clay exist particularly in the Maaninka area. In Kuopio exist part of Finland’s longest ridge belt which extends from the Joensuu region to the Pohjanlahti coast. The largest ridges are situated in Maaninka and Riistavesi. Going through Nilsiä’s centre there is also a ridge belt. The largest bogs are in Nilsiä’s north east part as well as Maaninka’s northern and western parts.
Traces of the Ice Age
The last, so called, Weichselian ice age period covered the whole of Finland with a mostly 2-3 km thick continental glacier The ice age started about 117,000 years ago and ended in Finland about 10,000 years ago when the continental glacier melted. The continental glacier was at its largest 20,000 to 19,000 years ago when it reached all the way to Berlin in the south.
Ice in the Kuopio region disappeared about 11,500 years ago after which time the lakes and seas born from the melting waters began to flush up the slopes of our hills. At its highest, the water was in the so-called Yoldia Sea stage, when the shore was 140-150 metres high. The Yoldia Sea shoreline can still be found on the slopes of the present day high hills.
The moving ice consumed the bedrock and carried the materials that had been dislodged. Among other things, the boulders, which moved very far with the ice in a north-easterly direction, tell us about ice movements.The crevices of the bedrock are sliced into streamlined silico-cliffs. At breaks, it cleared the valleys that are now filled with lakes, clay fields and bog strips. The direction of the ice is easily visible in the Kuopio region as many of the lakes in the area are in a northwest-southeast position.