Landforms and Surficial Deposits
The presence of surficial deposits and the distinctive land forms in Norway are closely related to the glacial history in the Quaternary era (last ca. 2.6 million years) and especially to our last ice age, the Weichselian (ca 117 000-11 700 years ago). Glacial erosion during this last and previous ice ages have carved out valleys, formed unique landscape features and left behind huge amounts of loose broken-down rock fragments. The glacial tracks and rock deposits are examined to help geologists interpret Norway's geological history and to understand the processes that have contributed to the landscape development.
Detailed information about the Norway's surficial deposits is also important from a societal perspective. Thorough mapping can provide comprehensive information about the types of raw materials and natural resources that are available, as well as providing information useful to those involved in construction, waste storage, uncovering resources, identifying potential natural hazards, sources of groundwater etc.
The glaciers eroded, shaped and deposited
Surficial Deposits are mapped according to dominant geological processes occurring during deposition. In Norway, most soil types are either directly or indirectly related to the movement of ice sheets, such as till or glacifluvial material, or as sediments that were washed out by the glaciers into the sea. Deposits that occur independent of glaciations may include, for example, block fields, landslide masses and river and beach deposits. These are often indirectly affected by what was left behind after a glacial period.
Landforms and terrain elements
The time required for landform formation, its dimensions and the processes involved can widely vary. Some formations may have been formed during a single episode, such as a landslide scar or glacial striations. However, recurrent processes taking place over several glacial and inter-glacial periods, have formed Norway's fjords, valleys and alpine landscapes. Terrains can be shaped erosion, and the reworking of the bedrock or sediments of the older landscape, or the deposition of landforms.
Landforms are created by a variety of geological processes. Ice sheets are a major transforming element, as evident from the elongated drumlins of moraine material that have deposited under ice. More often, however, glacial streams deposited and eroded material below, next to and in front of the glaciers, such as eskers, and marginal channel. Large deltas or submarine fan deposits form where the glacial streams reach a body of water (lake or sea).
Marine processes have washed, sorted and redistributed rock material ever since the glaciers began their retreat inland. This retreat resulted in the creation of a number of land formations as the continental surface lifted. One of the land formations are ridges, consisting of shoreline material, thrown far up on the continent by powerful storm waves. Isostatic uplift has also uncovered the former seabed, where landslide processes have formed the shards in the terrain in the form of mudslide. There are also many other processes that form the terrain elements. The diversity of geological processes, and the interaction between them, is reflected in an even greater diversity of landforms, which helps us solve the geological puzzle.