Weiteveen Lower Evaporite Member SKWFB

 

Premise Definition extended after NAM and RGD (1980) . Correlated with the lower Middle M√ľnder Marl in Germany by t Hart (1969)
Derivatio nominis Named after the village of Weiteveen, municipality of Schoonebeek, in the southeastern part of the province of Drente.
Type section Location map See figure (pdf)
  Well Schoonebeek-197 (pdf)
  Location N 52°38’58.0
E 07°02’34.2
  Depth 1470 to 1567 m
  Length 97 m along hole
  Reference NAM and RGD (1980)
Additional section Location map See figure (pdf)
  Well Ruinen-1 (pdf)
  Location N 52°44’09.8
E 06°27’12.8
  Depth 1140 to 1150 m
  Length 10 m along hole
  Well De Bente-1 (pdf)
  Location N 52°41’37.8
E 06°46’15.7
  Depth 1301 to 1327 m
  Length 26 m along hole
  Well Oldenzaal-2 (pdf)
  Location N 52°17’18.8
E 06°56’23.8
  Depth 482 to 573 m
  Length 91 m along hole
Definition It consists of an alternation of dolomitic and/or anhydritic claystones, anhydrites, halites and limestones. Over synsedimentary highs, the halite layers thin and disappear, accompanied by a marked decrease of the anhydrite content. t Hart (1969) mentions the existence of three distinct facies in the member: a basinal claystone facies (Schoonebeek-197), an intermediate marl/limestone facies (Oldenzaal-2), and a basin fringe oolitic or sandy coquina limestone facies (Ruinen-1). Glauconite can be encoun-tered in all three facies.
Upper Boundary The top is placed at a marked increase in GR-log readings and a drop in resistivity log readings, caused by the higher clay content of the Weiteveen Lower Marl Member.
Lower Boundary It conformably rests on the variegated Weiteveen Basal Clastic Member, or it unconformably overlies the Altena Group or older sediments. The base is placed at the lowermost carbonate or anhydrite bed.
Distribution Dutch part of the Lower Saxony Basin, which reaches the easternmost parts of the Dutch provinces of Groningen, Drente and Overijssel. May be absent around and over salt swells and domes.
Age Latest Kimmeridgian-Early Portlandian. The member is placed in zone Upper Malm 2 or B of the regional ostracod zonation (Wolburg (1949) ; Sung (1955) ; t Hart (1969) ).
Depositional Setting Highly-restricted lacustrine basin-margin to marginal-marine sub-basin setting. The formation of evaporites can be contributed to a combination of estuarine basin circulation and reworking of outcropping Triassic and Zechstein evaporites.
Sequence Stratigraphy Judging from the age of the deposits and their log patterns, they are thought to represent the Late Highstand of Haq (1988) ’s sequence LZA 4.7, most of LZB 1.1, up to the Transgressive systems tract of sequence LZB 1.2 in the basin centre. Thus they correlate with a significant period of relative Lowstand in the Dutch Central Graben (start of Scruff Greensand Formation in southern part, important depocentre reorganisation in the northern part). Along the basin margin the member only represents the interval around the sequence boundary of LZB 1.1.
References See References Upper Jurassic/ Lower Cretaceous

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