Z4 (Aller) Formation

Code
ZEZ4
Status
Formal (NAM & RGD 1980). Amended (Adrichem Boogaert & Kouwe 1994).
Lithological description

Claystone - anhydrite - salt sequence in the main basin and sub-basins, and a claystone - sandstone development along the basin margin.

Depositional setting

Marine.

Definition of lower boundary

Placed at the base of the Red Salt Clay Member.

Definition of upper boundary

Formed by the top of the Z4 Salt Member or the Z4 Pegmatite Anhydrite Member.

Thickness indication
Generally less than 130 m, up to 1642 m in L05-B-03.
Geographical distribution
Regional correlation
UK: Z4 Group; GER: Aller Folge (Z4); BEL: Z4 (Aller) Formation.
Age
latest Wuchiapingian - earliest Changhsingian.
Holostratotype
Depth (thickness) AH:
1235 - 1245 m (10 m)
Comments:
Sub-basin setting
Hypostratotype
Depth (thickness) AH:
4036 - 4096 m (60 m)
Comments:
Main-basin setting
Parastratotype
Depth (thickness) AH:
2194 - 2250 m (56 m)
Comments:
Main-basin setting
Hypostratotype
Depth (thickness) AH:
1797 - 1860 m (63 m)
Comments:
sandstone facies
Origin of name
Name derived from the German stratigraphic nomenclature, where it is used for the fourth evaporite cycle of the Zechstein Group (Richter-Bernburg 1955).
Previous name(s)
None.
Reviewed by (date)
Mark Geluk (2017).
References
NAM & RGD 1980. Stratigraphic nomenclature of The Netherlands. Verhandelingen van het Koninklijk Nederlands Geologisch Mijnbouwkundig Genootschap 32, 77 p.
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.
Richter-Bernburg, G. 1955. Stratigraphische Gliederung des deutschen Zechsteins - Z. Dt. Geol. Ges., 105, 593-645.
Cite as
TNO-GDN ([YEAR]). Z4 (Aller) Formation. In: Stratigraphic Nomenclature of the Netherlands, TNO – Geological Survey of the Netherlands. Accessed on [DATE] from http://acc.dinoloket.nl/en/stratigraphic-nomenclature/z4-aller-formation.