Site description

A look at the Geological General Map of Germany makes it clear that the eastern ridges of the Reinhardswald consist of hard rocks of the middle Buntsandstein, the depression, in which Frankenhausen also lies, of the soft mudstones of the upper Buntsandstein (Röt) - partly covered with loess - and the plateau adjoining to the west of limestones of the lower and middle Muschelkalk. The slightly hilly open depression lying between the plateaus to the north of the Kassel Basin extends over Hofgeismar to Trendelburg and is called the Hofgeismarer Rötsenke in the natural classification.

If we now zoom in on Frankenhausen and enlarge the geological map to a scale of 1:25000, the spectrum of geological mapping units expands. Besides Röt (so) and Löß (Lö) a total of 6 smaller basalt cones occur east of the federal road and the Jungfernbach, partly surrounded by tertiary sands (Eocene). East of the railroad line the rising slopes are again formed by red sandstone. Sporadically, but occurring on the whole map sheet, Tertiary quartzites up to block size are encountered.

Available are the results of soil estimation, which are available map-wise in a scale of 1:2000. The soil numbers range from 25-82, with areas with soil numbers between 55-75 occupying a large part of the area. The predominant soil type is parabraunerden of loess. Pelosols are sometimes found on the hilltops and colluvisols in the depressions.

In order to learn more about the soils and the current state of supply, the Department of Soil Science (Prof. Wildhagen, Department 11) carried out an extensive soil mapping in a 50 m grid of all areas. In addition, two soil monitoring plots were established on representative sites, which were intensively sampled and analyzed and will be re-examined at regular intervals in the future to determine long-term soil changes.

Soil profiles were described at approximately 1200 grid points on a 1m deep drill core (Pürkhauer) according to the mapping instructions and the following data were recorded for each horizon: Horizon name, depth, texture, stone content, humus content, RedOx features, stratigraphy, carbonate content, and any anomalies. A soil type was determined from the horizon sequences. After mapping, soil samples were collected from a depth of 0-30 cm (grassland 0-15 cm) within a 20 cm radius of the borehole on cropland and analyzed for the following parameters: _Ct, _Nt, _P2O5 and _K2O(CAL), Mg (_CaCl2), pH (_CaCl2), and occasionally _CaCO3 (Scheibler).

Profiles were excavated and described by students in several mapping practicums as guide profiles for area mapping. In combination with the borehole descriptions and the data of the soil estimation as well as the terrain model, which still has to be created, a soil type map for the domain will be developed.