Heksenberg Member NUVIH


Premise Originally defined as a formation by Kuyl (1975) ; further described by NAM and RGD (1980) . Status changed here from formation to member.
Derivatio nominis Named after the Heksenberg area near Heerlen (N 50°54'38", E 05°58'37").
Type section Location map See figure (pdf)
  Well Outcrop Beaujean, Herenweg, Heerlen (62B-43)
  Location N 50°54'42
E 05°35'37
  Length 20 m of section exposed
  Reference Kuyl (1975)
Additional section Location map See figure (pdf)
  Well Asten-1 (pdf)
  Location N 51°23'47.8
E 05°47'27.4
  Depth 722 to 800 m
  Length 78 m along hole
  Well Broeksittard 60D/1033 (pdf)
  Location N 51°00'46.3
E 05°53'35.5
  Depth 395 to 499.5 m
  Length 104.5 m along hole
Definition Sands with intercalated brown-coal seams, in two stacked clusters of 15-20 m and about 30 m thick respectively. These are the lateral extensions of the Frimmersdorf (top) and Morken I (bottom) coal seams of the Lower Rhine area. The total thickness of the member amounts to 90-100 m. At the top and base of the member rolled flints are frequently found. These represent remnants of former beach deposits. The uppermost flint bed is located at the base of the Middle Miocene transgression of sequence TB 2.5. The basal sands, underlying the Morken Seam, are at least partly of an intertidal origin. In the southeast they overlie marine beds of the Veldhoven Formation. Basinward they merge laterally into glauconiferous, open-marine beds of the Breda Formation.
Upper Boundary The Heksenberg Member is overlain by marine, generally glauconiferous sands of the Breda Formation where rolled flint pebbles occur at the base.
Lower Boundary For the lower boundary, see Ville Formation.
Distribution In the Roer Valley Graben in the southeastern Netherlands extending to the south and north over adjoining fault blocks.
Age Later part of Early Miocene to early part of Middle Miocene (Hemmoorian and Reinbekian Stages).
Depositional Setting Coastal-lowland environment.
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].