Zechstein Upper Claystone Formation

Code
ZEUC
Status
Formal (Van Adrichem Boogaert & Kouwe 1994).
Lithological description

Clastic interval between the highest recognisable carbonate, evaporite or siliciclastic member or formation of the Zechstein Group and the base of the Lower Germanic Trias Group. Lithologically the formation is composed of red-brown to pale brown, occasionally grey-green claystones with some anhydrite and/or carbonate stringers. These claystones often show remarkably low velocities on the acoustic log. In the upper part thin, well-cemented, sandy beds may occur.

Depositional setting

Large plain at the basin fringe under playa-like conditions. Grades into the lacustrine deposits of the Lower Buntsandstein Formation (Geluk et al. 1997).

Definition of lower boundary

Placed at the top of the highest underlying Zechstein evaporite or clastic member or formation.

Definition of upper boundary

Formed by the base of the Lower Germanic Trias Group. In the basin the unit rests directly on the Z4 Salt Member or Z5 Salt Member, whereas in the fringe area it can directly overlie the Z3 Carbonate, the sandstone members of the Z3 (Leine) and the Z4 (Aller) formations or locally even the Upper Rotliegend Group.

Thickness indication
Generally less than 100 m, but up to 1247 m in E16-04.
Geographical distribution
Regional correlation
UK: Bunter Shale Group; GER: Fulda Folge & Friesland Folge; BEL: Zechstein Upper Claystone Formation.
Age
Changhsingian.
Holostratotype
Depth (thickness) AH:
1212 - 1235 m (23 m)
Parastratotype
Depth (thickness) AH:
2178 - 2194 m (16 m)
Parastratotype
Depth (thickness) AH:
3992 - 4017 m (25 m)
Parastratotype
Depth (thickness) AH:
4378 - 4418 m (40 m)
Parastratotype
Depth (thickness) AH:
2711 - 2720 m (9 m)
Parastratotype
Well:
BQ160975 (Q16-01)
Depth (thickness) AH:
3817 - 3823 m (6 m)
Parastratotype
Depth (thickness) AH:
1708 - 1712 m (4 m)
Origin of name
Name applied to the claystone beds between the highest Zechstein evaporite and the base of the Lower Germanic Trias Group. These claystones were formerly attributed to the Basal Buntsandstein Member of the Lower Buntsandstein Formation or to the basal part of the Bunter Formation.
Previous name(s)
None.
Reviewed by (date)
Mark Geluk (2017).
References
Geluk, M.C., Van Wees, J.D., Grönloh, H., Van Adrichem Boogaert, A.B. 1997. Palaeogeography and paleotectonics of the Zechstein Group (Upper Permian) in the Netherlands. Proceedings of the XIII International Congress on the Carboniferous and Permian, 28th August-2nd September 1995, Krakow, Poland. Prace Panstwowego Instytut Geologicznego CLVII, part 2, 63-75.
Van Adrichem Boogaert, H.A. & Kouwe, W.F.P. 1994. Stratigraphic nomenclature of The Netherlands; revision and update by RGD and NOGEPA, Section D, Permian. Mededelingen Rijks Geologische Dienst, 50, 1-42.
Cite as
TNO-GDN ([YEAR]). Zechstein Upper Claystone Formation. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from http://acc.dinoloket.nl/en/stratigraphic-nomenclature/zechstein-upper-claystone-formation.