Geological coastal map of Lower Saxony 1: 25 000 — Coastal Holocene Profile Types (WFS Service)

Today’s coastal area with its landscape features, the islands, wadding and marshes, is geologically a very young structure that has only emerged in the last 8500 years under the influence of a sea level rise of about 25 m. The originally existing geest landscape, formed in the Ice Age, was flooded, partially redesigned and covered in varying thicknesses by holocene coastal deposits. These are mostly clay-sluffy, sometimes sandy cotton and brackish water sediments, which are loaded into the coastal area by the sea and rivers, or peat which have been accumulated in coastal bogs. In the area of the islands, this up to 35 m thick sediment body is sometimes superimposed by dunes reaching up to 25 m in height. The Geological Coast Map of Lower Saxony 1: 25 000 presents the holocene landscapes and coastal deposits in two maps covering the following topics: — Relief of the Holocene Base — Profile types of the coastal holocene. The representation of the profile types of the coastal holocene provides a generalised picture of the lateral distribution and vertical sequence of coastal deposits. The main and secondary profile types of the lithological order principle (BARCKHAUSEN et al. 1977, STREIF 1979, 1998) and the dune areas on the islands. Map sections for which no statements can be made about the profile types of the coastal holocene are characterised by light blue area color. If a map sheet includes geest areas, these are displayed without surface color. A highly schematised geological section illustrates in profile columns the layer structure as well as the position relationships of the clastic or organic sequences of the coastal holocene to each other and represents the resulting 3 main profile types and 12 secondary profile types. The Klastic complex (main profile type X) and its secondary profile types are characterised by a predominance of sandy to clay sediments. Low-powered peat can only occur here at the base of the holocene sediment body or its surface. Characteristic of the toothing complex (main profile type Y) and its secondary profile types is a more or less intensive toothing of clastic sediments with turned on peat. In addition to the switched on peat layers, peat can also occur here at the base of the holocene sediment body or on its surface. The peat complex (main profile type Z) and its secondary profile types dominate low moor or high mooring. Here, clastic sediments can occur as a less powerful activation within the peat or form lower-powered top layers or basal layers of the peat.