Littoral deposits
Littoral refers to the shoreline and littoral deposit areas arose when the Ice Age loosened its grip about 10,400 years ago, when the land of Rokua Geopark started to rise from the bed of the ancient Baltic Sea, Ancylus Lake. The peak of the highest point in the area, Pookivaara, rose above the surface of the water at this time, forming an island in the middle of a wide open lake. Over thousands of years the waves moulded the slopes of the ridge, forming a series of ridges, descending in steps, which today continue all the way to the shore of the Gulf of Bothnia.
Where can these littoral deposit areas be seen?
Steep shore ridges and slopes are common throughout the Rokua Geopark area. In places they are still moulded by the power of flowing water, waves, ice and wind. Sometimes the erosion of the slopes is revealed by the trees. The raised roots of pine trees growing on top of a bluff show how conditions are becoming untenable and the trees slide down the hill. It is easiest to spot littoral deposit areas on the roads that cut through them. Good spots include Ahmaskangas, the Suppa Information Centre on the road to Nuojua and Manamansalo.