Helm Member

Code
SLDBH
Status
Formal (Van Adrichem Boogaert & Kouwe 1993).
Lithological description

Silt- to claystone, light- to dark-grey and light-brown coloured, with abundant carbonaceous laminae which often show pyritised burrows, and with thin sandstone beds (mostly less than 1 meter). The clear sands have fine to medium, subangular to rounded grains. Minor occurrences of medium- to dark-grey claystone and white to light-brown limestone and dolomite are present. Lignite is locally abundant. In some wells (P03-02), abundant fragments of bivalves and gastropods have been encountered.

Depositional setting

Deposited in a marginal-marine setting at the landward (backbarrier) position of the beach-barrier deposits of the sandy Kotter and Helder Members. Restricted conditions in a lagoonal setting with storm influences.

Definition of lower boundary

Unconformable with the underlying Vlieland Claystone or Sandstone formations.

Definition of upper boundary

Overlain by the sandy Helder Member of the Vlieland Sandstone Formation.

Thickness indication
Generally less than 76 m, but up to 150 m in P03-02.
Geographical distribution
Regional correlation
UK: Humber Group; GER: ?; BEL: -.
Age
latest Berriasian - early Valanginian.
Holostratotype
Depth (thickness) AH:
1347 - 1379 m (32 m)
Parastratotype
Depth (thickness) AH:
1815 - 1966 m (151 m)
Origin of name
Named after the Helm oil field, block Q01, Dutch offshore sector.
Previous name(s)
None.
Reviewed by (date)
Sander Houben (2017).
References
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]). Helm Member. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from http://www.dinoloket.nl/en/stratigraphic-nomenclature/helm-member.