Heers Member NLLFS


Premise The Heers Sand Member as originally defined by NAM and RGD (1980) embraced the Swalmen Member as well. The latter is now considered to be a separate member. The lithological affix in the name of the member has been omitted. The Belgian Heers Formation comprises two members: the Sand of Orp followed by the Marls of Gelinden (Marechal and Laga (1988) ). The Dutch Heers Member is the equivalent of the Belgian Sand of Orp.
Derivatio nominis Named after the municipality of Heers in the south of the Belgian province of Limburg.
Type section Location map See figure (pdf)
  Well Veldhoven-1 (pdf)
  Location N 51°26'20.8
E 05°21'37.2
  Depth 1412 to 1423 m
  Length 11 m along hole
  Reference NAM and RGD (1980)
Definition Very fine-grained, light- to dark-green/grey, glauconitic, partly calcareous sands, with some intercalated clay beds. Contain shells locally. Locally, the unit comprises two coarsening-upward sequences.
Upper Boundary In the southeastern Netherlands an abrupt transition to the overlying Gelinden Member exists. In the rest of the Netherlands a rather sharp boundary with the Landen Clay Member is observed.
Lower Boundary The Heers Member either clearly unconformably overlies Mesozoic deposits, or mildly unconformably overlies the Houthem Formation or the Swalmen Member. The boundary of the sands of this member and the underlying units is sharp.
Distribution Generally, south of the ‘Southern Early Tertiary High’ and locally north of it i.e. northern Gelderland and the IJsselmeer area, northern Noord-Holland and the western parts of the Waddenzee and Friesland.
Age Late Paleocene. In general, this unit is devoid of foraminifera and nannoplankton.
Depositional Setting Shallow open marine.
Sequence Stratigraphy The unit has been deposited during the extensive flooding of the Transgressive systems tract of cycle TA 2.1.
References See References Tertiary

Van Adrichem Boogaert, H.A. & Kouwe, W.F.P., 1993-1997. [Stratigraphic unit]. In: Stratigraphic Nomenclature of the Netherlands.
Retrieved [Datum] from [url].