Z5 (Ohre) Formation ZEZ5


Premise Formation defined by van Adrichem Boogaert & Kouwe (1994). The occurrence of this formation in the Netherlands was first mentioned by Plomp and Geluk (1988) and Geluk and Remmelts (1990). It is the youngest evaporite cyle in the Zechstein recognized in this country.
Derivatio nominis Name derived from the German stratigraphic nomenclature, where it was introduced by Reichenbach (1970).
Type section Location map See figure (pdf)
  Well Drouwenerveen-Zuideind-1 (pdf)
  Location N 53°57’41.7
E 06°52’16.9
  Depth 4017 to 4036 m
  Length 19 m along hole
Definition The fifth, and presumably youngest, Zechstein evaporite cycle to be distinguished in the Netherlands, consisting of claystone and rock salt. This formation is only present in places where the Z4 Salt Member is fully developed (see under 4.4.3). Its presence was established through correlations with Germany, as published by Best (1989). It is advised to distinguish this formation only when it contains rock salt; otherwise the sediments should be assigned to the Upper Zechstein Claystone Formation.
Upper Boundary The upper boundary has been placed at the top of the rock salt and constitutes the contact with the Zechstein Upper Claystone Formation.
Lower Boundary The lower boundary has been placed at the base of the claystone underlying the rock salt. This claystone usually is the third claystone peak above the potassium-magnesium rich salt bed of the Z4 Salt Member.
Distribution This formation is only recognised in the deepest parts of the main basin, i.e. in the northeastern onshore and the northern offshore areas.
Age Thuringian, Late Permian.
Subdivision The fifth evaporite cycle is incomplete, as it lacks carbonate. The presence of very thin anhydrite beds below and above the halite is inferred from wire-line logs. The subdivision of the formation is as follows:
  ZE Zechstein Group
  ZEZ5 Z5 (Ohre) Formation
  ZEZ5H Z5 Salt Member
  ZEZ5R Z5 Salt Clay Member
References See References Permian

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