Middle Graben Formation

Code
SLCM
Status
Formal (NAM & RGD 1980). Amended (Van Adrichem Boogaert & Kouwe 1993).
Lithological description

Grey, locally very silty, carbonaceous claystones. In the northern part of the F-quadrant one thick or locally two sandstone beds may be intercalated. At the base of the formation three thin but distinct coal seams occur.

Depositional setting

Lacustrine to marginal marine embayment.

Definition of lower boundary

Placed below the base of the lowermost distinct coal seam, immediately overlying thick sand beds.

Definition of upper boundary

Conformable contact with the marine claystones of the Kimmeridge Clay Formation or barrier sands of the Upper Graben Formation in the northern part of the Dutch Central Graben. To the south it is overlain by the coal-bed dominated Puzzle Hole Formation. The transition from the Middle Graben Formation to the Puzzle Hole Formation is gradual.

Thickness indication
500 m.
Geographical distribution
Regional correlation
UK: Humber Group; GER: ?; BEL: -.
Age
early Oxfordian - middle Oxfordian.
Holostratotype
Depth (thickness) AH:
2670 - 3090 m (420 m)
Origin of name
Named after the Central Graben.
Previous name(s)
None.
Reviewed by (date)
Sander Houben (2017).
References
NAM & RGD 1980. Stratigraphic nomenclature of The Netherlands. Verhandelingen van het Koninklijk Nederlands Geologisch Mijnbouwkundig Genootschap 32, 77 p.
Van Adrichem Boogaert, H.A. & Kouwe, W.F.P. 1993. Stratigraphic nomenclature of The Netherlands; revision and update by RGD and NOGEPA, Section G, Upper Jurassic and Lower Cretaceous. Mededelingen Rijks Geologische Dienst, 50, 1-80..
Cite as
TNO-GDN ([YEAR]). Middle Graben Formation. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from http://www.dinoloket.nl/en/stratigraphic-nomenclature/middle-graben-formation.