Wierden Member

NUBXWI

Formal (Schokker et al. 2005; Schokker et al. 2007).

Light brown to yellowish brown very fine to medium sand, well-sorted and rounded.

Periglacial aeolian (coversand).

Sharp contact with coarser fluvial and fluvioglacial sand (Kreftenheye, Beegden and Sterksel Formations), gradual transition into loess (Liempde Member, Boxtel Formation).

Commonly exposed at the surface. Regionally, erosive contact with tidal sand and clay (Naaldwijk Formation), and locally, erosive contact with small-scale fluvial or fluvioperiglacial deposits (Singraven Member, Boxtel Formation). Locally, gradual transition into peat (Basal Peat Bed, Nieuwkoop Formation). Offshore, partly unconformably overlain by marine sand (Southern Bight Formation).

Generally up to 1 m, more than 2 m in preserved dunes.

Common throughout the Netherlands and in the northern half of the Dutch North Sea.

North Sea: Twente Formation (mapped in conjunction with the British Geological Survey); UK: Coversands, Older blown sand, Breighton Sand Formation, Sutton Sand Formation; GER: onshore Niederungssand and Hangsand, offshore Limnisch-fluviatile Schichten (Sindowski, 1970); BEL: part of Gent Formation, Wildert Member (Vernes et al. 2018).

Late Pleistocene (Late-Weichselian).

Named after the village of Wierden, in the eastern Netherlands.

Dekzand, jong dekzand (Van der Hammen & Wymstra 1971), coversand deposits (Twente Formation; Doppert et al. 1975).

Wim Dubelaar (2018), Sytze van Heteren (2019).

Doppert, J.W.Chr., Ruegg, G.H.J., Van Staalduinen, C.J., Zagwijn, W.H., Zandstra, J.G. 1975. Formaties van het Kwartair en Boven-Tertiair in Nederland. In: Zagwijn, W.H., Van Staalduinen, C.J. (eds.): Toelichting bij geologische overzichtskaarten van Nederland. Rijks Geologische Dienst, Haarlem, 11-56.

McMillan, A.A., Hamblin, R.J.O., Merritt, J.W. 2011. A lithostratigraphical framework for onshore Quaternary and Neogene (Tertiary) superficial deposits of Great Britain and the Isle of Man. British Geological Survey Research Report, RR/10/03, 343 p.

Schokker, J, De Lang, F.D., Weerts, H.J.T., Den Otter, C., Passchier, S. 2005. Beschrijving lithostratigrafische eenheid. Nederlands Instituut voor Toegepaste Geowetenschappen TNO. Utrecht.

Schokker, J., Weerts, H.J.T., Westerhoff, W.E., Berendsen, H.J.A., Den Otter, C. 2007. Introduction of the Boxtel Formation and implications for the Quaternary lithostratigraphy of the Netherlands. Netherlands Journal of Geosciences / Geologie en Mijnbouw, 86, 197-210.

Van der Hammen, T., Wijmstra, T.A. (eds.) 1971. The upper Quaternary of the Dinkel valley (Twente, eastern Overijssel, the Netherlands). Mededelingen Rijks Geologische Dienst, Nieuwe serie 22, 55-213.

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.