During the cold periods of the Weichselian glaciation, the ice masses grew and moved across the landscape. Like a bulldozer, the ice pushed rocks, gravel, and remains of dead animals in front of itself. Where the ice reached, it deposited the gathered material as so-called terminal moraines. During warmer periods the ice melted away. The water gushed with great force through the landscape and led some of the material into the ocean, while some was deposited on land. Today, we collect gravel from these sediments, and we find remains of the past animals in the form of teeth, skulls, and bones.