J. Mulder

Daliegaten en daliebulten in de Zeevang (N.H.).

Historisch Geografisch Tijdschrift 24 (2006) 97 - 106.

Tijdens de bodemkartering van het veenweidegebied De Zeevang boven Edam in 1994 zijn op een perceel enkele koepelvormige bulten van zo'n 5 meter in doorsnede ontdekt. Daarin is een circa 3,50 meter dik verstoord pakket veen aangetroffen, terwijl de veendikte direct naast de buit niet meer dan circa 1,50 meter bedroeg. Het was snel duidelijk dat het een vergelijkbaar fenomeen als de daliegaten betrof. Bij de boeren staan ze bekend als 'veenkringen', in dit artikel worden ze daliebulten genoemd. Vanwege de grote, historische betekenis heeft de opdrachtgever voor het bodemkundige onderzoek, de Dienst Landelijk Gebied regio West, aan het toenmalige Staring Centrum (nu Alterra) een aanvullende opdracht verstrekt om de daliebulten te inventariseren.

'Daliegaten' and 'daliebulten' in the De Zeevang area (province of North Holland).

In the Middle Ages (11th / 12th century) large parts of the province of North-Holland were covered by raised peat bog, which had developed on top of clay sediments. The highest part of the land consisted of extensive moors, sedge and reedlands. During the 11th / 12th century this peat area was systematically reclaimed by digging drain ditches. At the beginning it was possible to cultivate crops on the well drained peat soils. Pits were dug through the peat to extract limy clay from underneath. The limy clay was probably mixed with stable manure and used as fertilizer. Much o the peat has now disappeared due to erosion, oxidation or extraction. In many places in the province of North-Holland circular depressions in the grassland, which the farmers call daliegaten have been found. The soil profile shows a mixture of black peat and peaty material, whereas the surrounding soil consists of clay. In the peat area, called 'De Zeevang' some 25 kilometers north of Amsterdam land surveyors discovered circular dome shaped bulges. The soil profile in these areas consists of a mixture of brown peat of bog moss, sedges and reed, about 3,0 - 3,5 meters thick, whereas the surrounding soil profile shows a succession of layers (bog moss on sedges on reed on clay) that is naturally seen in peat. This layer is about 1,0 - 1,5 meter thick. These bulges are called daliebulten. Hundreds of daliebulten were discovered during a land survey of 'De Zeevang' in 1995.