The Weißes Fenn Marzahne is a lake, a boggy wetland and a

natural monument A natural monument is a natural or natural/cultural feature of outstanding or unique value because of its inherent rarity, representative of aesthetic qualities or cultural significance. Under World Commission on Protected Areas guidelines, nat ...

area in the county of

Potsdam-Mittelmark Potsdam-Mittelmark is a ''Kreis'' (district) in the western part of Brandenburg, Germany. Its neighbouring administrative units are (clockwise from the north) the district of Havelland, the free cities of Brandenburg and Potsdam, the state of Berl ...

, in the borough of

Havelsee Havelsee () is a town in the Potsdam-Mittelmark district, in Brandenburg, Germany. It is situated on the river Havel, 12 km northwest of Brandenburg. The Pritzerbe Ferry, a vehicular cable ferry, crosses the Havel between Havelsee and Kütz ...

north of the village of Marzahne in the Seelensdorf Forest and Marzahn Heath.

History

The Weißes Fenn Marzahne was formed after the last cold period, the

Weichselian Glaciation The Weichselian glaciation was the last glacial period and its associated glaciation in northern parts of Europe. In the Alpine region it corresponds to the Würm glaciation. It was characterized by a large ice sheet (the Fenno-Scandian ice sheet) ...

. Advancing ice masses pushed a series of

tunnel valley A tunnel valley is a U-shaped valley originally cut under the glacial ice near the margin of continental ice sheets such as that now covering Antarctica and formerly covering portions of all continents during past glacial ages. They can be as lo ...

basins similar to the parallel Beetzsee-Riewendsee- or Bohnenland-Görden glacial valley, in which meltwaters flowed or collected. These ran from northeast to southwest in the direction of the advancing ice. In this series of tunnel valleys, lakes were subsequently formed, like the Pritzerber See in the southwest. Later low lines of dunes crossed the valley bottoms and they still do today in the northeast of the row of tunnel valleys. These lines of dunes formed a barrier for the Weißes Fenn ("White Fen") to the southwest, so that water could no longer drain in that direction and a boggy wetland was created. In the modern period, a ditch, the Roter Graben, was cut to drain the wetland and the lake. This empties into the Pritzerber See. The Weißes Fenn Marzahne with the Marzahner Fenn, an ice age glacial tongue basin which lies about 2 kilometres to the southeast.

Protected areas

The Weißes Fenn Marzahne was placed in its entirety under protection as an area natural monument. It is also part of the

Special Area of Conservation A Special Area of Conservation (SAC) is defined in the European Union's Habitats Directive (92/43/EEC), also known as the ''Directive on the Conservation of Natural Habitats and of Wild Fauna and Flora''. They are to protect the 220 habitats and ap ...

known as the ''Weißes Fenn und Dünenheide'', to which parts of the Marzahner Fenn Nature reserve and Dünenheide belong. In addition it is part of the

protected landscape Protection is any measure taken to guard a thing against damage caused by outside forces. Protection can be provided to physical objects, including organisms, to systems, and to intangible things like civil and political rights. Although th ...

and nature park of Westhavelland.

References

{{DEFAULTSORT:Weisses Fenn Marzahne Glacial lakes Natural monuments in Germany BWeisses Fenn Marzahne Potsdam-Mittelmark Lakes of Brandenburg Bogs of Brandenburg Regions of Brandenburg