Heksenberg Member

Code
NUBRHE
Status
Formal (Zagwijn & Van Staalduinen 1975). Amended (NAM & RGD 1980; Van Adrichem Boogaert & Kouwe 1997; Westerhoff 2003).
Lithological description

White to grey fine to medium sand with intercalated lignite seams in two stacked clusters. Common rolled flint at top and base.

Depositional setting

Coastal-lowland, including beach (rolled flint) and intertidal (basal sand).

Definition of lower boundary

Generally, unconformable contact with shallow-marine silty, glauconitic sand (Kakert Member, Breda Formation). Locally, unconformable contact with shallow-marine very fine, glauconitic sand and clay (Veldhoven Formation).

Definition of upper boundary

Generally, sharp and unconformable contact with shallow-marine, glaucogenic sand with rolled flint (other units within the Breda Formation).

Thickness indication
Up to 100 m. Lignite stacks are 15-20 m and about 30 m thick.
Geographical distribution
Roer Valley Graben in the southeastern Netherlands, extending to the south and north over adjoining fault blocks. Basinward transition into open-marine glauconitic sand (other units within the Breda Formation). Lignite seams form the lateral extensions of the Frimmersdorf (top) and Morken I (bottom) seams (Ville Formation).
Regional correlation
North Sea: not present; UK: not present; GER: ?; BEL: Bolderberg Formation, Genk Member (Vernes et al. 2018).
Age
late early Miocene - early middle Miocene.
Holostratotype
Well:
G62B0043 (Quarry Beaujean, Herenweg, Heerlen)
Depth (thickness) AH:
20 m of section
Parastratotype
Depth (thickness) AH:
722 - 800 m (78 m)
Parastratotype
Depth (thickness) AH:
395.0 - 499.5 m (104.5 m)
Origin of name
Named after the Heksenberg area near the city of Heerlen in the southeastern Netherlands.
Previous name(s)
Heksenberg Formation (Van Adrichem Boogaert & Kouwe 1997).
Reviewed by (date)
Dirk Munsterman (2018), Sytze van Heteren (2019).
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. 1997. Stratigraphic nomenclature of The Netherlands, revision and update by RGD and NOGEPA, Section I, Tertiary. Mededelingen Rijks Geologische Dienst, 50, 1-39.
Vernes, R.W., Deckers, J., Bakker, M.A.J., Bogemans, F., De Ceukelaire, M., Doornenbal, J.C., den Dulk, M., Dusar, M., Van Haren, T.F.M., Heyvaert, V.M.A., Kiden, P., Kruisselbrink, A.F., Lanckacker, T., Menkovic, A., Meyvis, B., Munsterman, D.K., Reindersma, R., ten Veen, J.H., van de Ven, T.J.M., Walstra, J., Witmans, N. 2018. Geologisch en hydrogeologisch 3D model van het Cenozoïcum van de Belgisch-Nederlandse grensstreek van Midden-Brabant / De Kempen (H3O – De Kempen). Studie uitgevoerd door VITO, TNO-Geologische Dienst Nederland en de Belgische Geologische Dienst in opdracht van Vlaams Planbureau voor Omgeving, Vlaamse Milieumaatschappij, TNO, Geologische Dienst Nederland, Nederlandse Provincie Noord-Brabant, Brabant Water, Programmabureau KRW/DHZ Maasregio.
Westerhoff, W.E. 2003. Beschrijving lithostratigrafische eenheid. Nederlands Instituut voor Toegepaste Geowetenschappen TNO. Utrecht.
Zagwijn, W.H. & Van Staalduinen, C.J. 1975. Toelichting bij geologische overzichtskaarten van Nederland, met bijbehorende 5 kaarten (1 : 600 000) en 3 overzichtsprofielen. Rijks Geologische Dienst, Haarlem.
Cite as
TNO-GDN ([YEAR]). Heksenberg Member. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from https://www.dinoloket.nl/en/stratigraphic-nomenclature/heksenberg-member.