Before revision: The Pinge is usually surrounded by a ring-shaped mound (German: Halde) as a result of the subsidence of the surface of the terrain .Mineralienatlas.de: Pinge A number of Pingen form trenches up to 250 metres long and 15 metres wide.Reinhard Köhne: Historischer Erzbergbau im Sauerland: Gruben und Gräben auf dem Dach Westfalens (accessed on 6 January 2012; pdf; 9.0 MB) Excavation Formation of a Pinge as a result of coal mining.
After revision: The Pinge , which is caused, is usually surrounded by a ring-shaped mound (German: Halde) as a result of the subsidence of the surface of the terrain .Mineralienatlas.de: Pinge A number of Pingen form trenches up to 250 metres long and 15 metres wide.Reinhard Köhne: Historischer Erzbergbau im Sauerland: Gruben und Gräben auf dem Dach Westfalens (accessed on 6 January 2012; pdf; 9.0 MB) Excavation Formation of a Pinge as a result of coal mining.