moreenimuodostelmat

Moreenimuodostelmat, known in English as till or boulder clay, are glacial landforms consisting of unsorted, unstratified glacial drift. They are deposited directly by glacial ice, meaning the material has not been transported or sorted by meltwater. This unsorted nature is a key characteristic, containing a wide range of particle sizes from fine clay and silt to sand, gravel, and even large boulders.

These formations are created as glaciers advance, carrying debris on their surface and within the ice. As the ice melts or retreats, this accumulated material is dropped. Two primary types of moreenimuodostelmat exist: ground moraine and terminal moraine. Ground moraine forms a widespread, undulating layer of till deposited beneath the glacier. Terminal moraines, in contrast, are ridges of till deposited at the furthest extent of a glacier's advance, marking its maximum reach. These ridges can be quite substantial and are a testament to the erosional and depositional power of ice sheets. The uneven topography often associated with moreenimuodostelmat can influence drainage patterns and soil types in the landscape.