Friesland Member

KNNSF

Formal (Van Adrichem Boogaert & Kouwe 1993).

Mainly consists of fine- to medium-grained argillaceous, glauconitic sandstones, although locally grading into conglomeratic sandstones. Bioturbation, mica, shell fragments and lignite particles are often present.

Basal transgressive sands, which were intensely reworked by bioturbation, waves, storms, and some tides, or in prograding coastal-barrier systems or offshore shoals. Open-marine to proximal coastal setting.

Conformably to mildly unconformably overlies sediments of the Schieland Group or the Scruff Group, or the Zuidwal Volcanics Formation in the Central Graben, Terschelling Basin and Vlieland Basin. The lower boundary of the formation is generally sharply defined. The member onlaps onto the Friesland Platform, Noord-Holland Platform/Central Netherlands Basin, Groningen High, Texel-IJsselmeer High, and can unconformably rest on much older deposits (Triassic, Permian, Carboniferous).

The conformable contact with the Vlieland Claystone Formation forms the top.

Up to 200 m.

UK: Valhall Formation; GER: ~Minden-Braunschweig-Gruppe; BEL: -.

latest Berriasian - early Valanginian in the Vlieland and Terschelling Basins. Due to gradual onlap, its age can be as young as Barremian on the Friesland Platform, Groningen High, Noord-Holland Platform/Central Netherlands Basin and Texel-IJsselmeer High.

Named after the province of Friesland in the north of the Netherlands.

None.

Sander Houben (2017).

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..