The BGS Lexicon of Named Rock Units — Result Details

Roter Salzton Formation

Computer Code: RTSZ Preferred Map Code: notEntered
Status Code: Full
Age range: Guadalupian Epoch (PUG) — Lopingian Epoch (PUL)
Lithological Description: The Roter Salzton Formation consists of red-brown, occasionally purple-brown to grey, commonly silty, soft to firm, amorphous to blocky mudstones. The formation contains varying quantities of interbedded clear, colourless to pale pink-orange, massive halite and bright orange-red, opaque, massive, hard potassium and salts (most commonly carnallite). The most salt-enriched sequences occur towards the centre and southeast of the basin (e.g. 49/24-1). Laminae of white to grey anhydrite are recorded locally (e.g. 42/22-1).
Definition of Lower Boundary: The lower boundary of the Roter Salzton Formation is defined by a downward change from red-brown, saliferous mudstones to halite and K/Mg salts of the Leine Halite Formation. It is marked by a sharp downward increase in velocity. Where halite is present at the top of the Leine Halite Formation, the gamma log shows a sharp downward decrease in values (e.g. 41/25a-1). In wells where K/Mg salts occur at the top of the Leine Halite Formation, the gamma log shows a sharp downward increase (e.g. 49/22-3).
Definition of Upper Boundary: The upper boundary of the Roter Salzton Formation is normally marked by a sharp downward change from white-grey anhydrite of the Pegmatitanhydrit Formation to red-brown, halite and K/Mg salt bearing mudstones. It is characterized on density and velocity logs by a sharp downward decrease in values; the gamma log typically exhibits a similarly sharp increase in values downhole. The boundary is less well defined, particularly on the gamma log, where the overlying Pegmatitanhydrit Formation is thin or absent and the Roter Salzton Formation contains abundant halite and K/Mg salts (e.g. 44/22-3).
Thickness: The Roter Salzton Formation is typically 10 m thick, but locally reaches over 20 m (e.g. 47/8-1).
Geographical Limits: The Roter Salzton Formation is present throughout much of the Southern North Sea Basin. It is, however, absent from the Mid North Sea High and is locally absent, or not recognizable, in the centre of the basin, where halokinesis has disturbed the normal stratigraphic succession.
Parent Unit: Zechstein Group (ZG)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Reference Section  North Sea well 41/25a- 1: 1177.5—1198 m (3863-3930 ft) (Johnson et al., 1994). 
Reference Section  North Sea well 49/26- 4 (Rhys, 1974, table 2, fig. 3): 1588-1596.5 m (5210-5238 ft) (Johnson et al., 1994). 
Reference(s):
Johnson, H, Warrington, G and Stoker, S J. 1994. 6. Permian and Triassic of the Southern North Sea. In: Knox, R W O'B and Cordey, W G (eds.) Lithostratigraphic nomenclature of the UK North Sea. British Geological Survey, Nottingham. 
Cameron, T D J. 1993. 4. Triassic, Permian and pre-Permian of the Central and Northern North Sea. In: Knox, R W O'B and Cordey, W G (eds.) Lithostratigraphic nomenclature of the UK North Sea. British Geological Survey, Nottingham. 
Cameron, T D J, Crosby, A, Balson, P S, Jeffery, D H, Lott, G K, Bulat, J, and Harrison, D J. 1992. The geology of the southern North Sea. United Kingdom offshore regional report. (London: HMSO for the British Geological Survey.) 
NAM and RGD (Nederlandse Ardolie Maatschappij and Rijks Geologische Dienst) 1980. Stratigraphic nomenclature of the Netherlands. Transactions of the Royal Dutch Geological and Mining Society of Delft. 
Rhys, G H. 1974. A proposed standard lithostratigraphic nomenclature for the southern North Sea and an outline structural nomenclature for the whole of the (UK) North Sea. Report of the Institute of Geological Sciences, 74/8. 
Smith, D B. 1980. The evolution of the English Zechstein basin. In: Fuchtbauer, H, and Peryt, T M (eds.) The Zechstein basin with emphasis on carbonate sequences. Contributions to Sedimentology 9, 7-34. 
Smith, D B. 1989. The late Permian palaeogeography of north-east England. Proceedings of the Yorkshire Geological Society, Vol.47, 285-312. 
Smith, D B, Brunstrom, R G W, Manning, D I, Simpson, S and Shotton, F W. 1974. A correlation of Permian rocks in the British Isles. Geological Society of London Special Report No. 5. 
Smith, D B, Harwood, G M, Pattison, J and Pettigrew, T H. 1986. A revised nomenclature for Upper Permian strata in eastern England. 9-17 in Harwood, G M and Smith, D B (editors). The English Zechstein and Related Topics. Geological Society Special Publication No.22. 
Taylor, J C M, and Coulter, V S. 1975. Zechstein of the English sector of the Southern North Sea. In: Woodland, A W (ed.) Petroleum and the continental shelf of North-West Europe, 249-263. Applied Science Publishers, London. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable