Partly consolidated (tough) greyish brown to greyish green silty clay, with fine sand in laminae and desiccation cracks. Extensively bioturbated, locally cryoturbated (Cameron et al., 1989). Desiccated and rooted at the top, with soil horizons (pyrite nodules).
Regressive brackish lagoonal to stream-fed lacustrine.
Definition of lower boundary
Unconformable contact with marine sand (Eem Formation).
Definition of upper boundary
Top characterised by desiccation, bioturbation and soil formation. Unconformably overlain by glaciolacustrine clay (Dogger Bank Member, Dogger Bight Formation), periglacial sand (Boxtel Formation) or marine sand (Naaldwijk Formation).
Generally up to 10 m, thicker toward border with British part of the North Sea.
Extensive areas in the central part of the Dutch North Sea (Oele, 1971; Cameron et al. 1988).
North Sea: Brown Bank Formation (defined and mapped in conjunction with the British Geological Survey; Cameron et al., 1989); UK: not present; GER: not present; BEL: not present.
Late Pleistocene (Early Weichselian).
Origin of name
Named after a prominent tidal ridge in the Dutch sector of the southern North Sea.
Brown Bank Formation (Oele 1971).
Reviewed by (date)
Wim Dubelaar (2018), Sytze van Heteren (2019).
Cameron, T.D.J., Schüttenhelm, R.T.E., Laban, C. 1989. Middle and Upper Pleistocene and Holocene stratigraphy in the southern North Sea between 52° and 54° N, 2° to 4° E. In: Henriet, J.P. De Moor, G. (eds.): The Quaternary and Tertiary geology of the Southern Bight, North Sea. Brussels, Belgian Geological Survey, 119-135.
Oele, E. 1971. The Quaternary of the southern area of the Dutch part of the North Sea. Geologie en Mijnbouw 50, 461-474.
TNO-GDN ([YEAR]). Brown Bank Member. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from http://www.dinoloket.nl/en/stratigraphic-nomenclature/brown-bank-member.