Marine ingressions into the Middle/Late Permian saline lake of the Southern Permian Basin (Rotliegend, Northern Germany) possibly linked to sea-level highstands in the Arctic rift system Berit Legler ⁎, Jörg W. Schneider TU Bergakademie Freiberg, Institute of Geology, Bernhard-von-Cotta-Str. 2, 09596 Freiberg, Germany ABSTRACT ARTICLE INFO Article history: Received 24 August 2007 Received in revised form 8 May 2008 Accepted 16 June 2008 Keywords: Arctic rift system Marine ingression Rotliegend Southern Permian Basin Stable isotope Sulphur A huge saline lake existed in the Southern Permian Basin (SPB) of Northwest Europe during Late Wordian to Early Wuchiapingian. More than 2500 m thick continental siliciclastics and evaporites of the Upper Rotliegend II were deposited before the marine Zechstein transgression flooded the basin. Marine deposition took place in the Arctic rift system between East Greenland and the Fennoscandian Shield at that time interval. Sediments of the Foldvik Creek-Group reflect relative sea-level fluctuations. Short-termed pre- Zechstein ingressions from the Boreal realm into the SPB are known by the marine lamellibranch Liebea reichei. However, sedimentological analysis of different saline lake horizons show, that the marine influenced saline lake horizon does not differ lithologically from other saline lake claystone layers in the Rotliegend succession. The 87 Sr/ 86 Sr ratios of anhydrite (0.7089–0.7100) reflect deposition in a continental setting. In contrast to this, S-isotopic values (more than +11.7‰ CDT) reflect marine pre-Zechstein ingressions into the SPB in the middle Niendorf and Munster Members. S-isotopic values of anhydrite can be used as an indicator for marine influence in the SPB. The pre-Zechstein ingressions superimpose the climatic triggered lake-level fluctuations of the Rotliegend saline lake. Two marine ingressions can be integrated into a set of regularly recurring abnormities in the depositional evolution. These important evolutionary steps, the saline lake formation, the Garlstorf ingression, the P, Ameland and Bahnsen lake level highstands, the Niendorf ingression, and the Zechstein transgression, show a periodicity of more or less 1 Ma. One million year cyclicity is also known from deposits of the Arctic rift system in East Greenland (Wegener Halvø and Ravnefjeld Formations). A correlation of the Upper Rotliegend II-deposits with the succession of East Greenland is proposed, based on the assumption that the marine ingressions as well as the exceptionally intensive saline lake expansions could be linked to sea-level highstands in the Arctic rift system. The result is the first correlation of Upper Rotliegend II-deposits with marine strata. © 2008 Elsevier B.V. All rights reserved. 1. Introduction Rotliegend (Mid to Late Permian) deposition in the Southern Permian Basin (SPB; Fig. 1) is well understood from data derived from several decades of natural gas exploration. The understanding of the sedimentary environment as well as the triggering parameters of deposition has become increasingly detailed. The collated research from the North German basin resulted in the German lithostratigraphical subdivision of Rotliegend deposits in 1995 (Plein, 1995). This summary stimulated further research. Rotliegend sedimentation in a desert environment was triggered mainly by tectonic activity and climatic fluctuations. Marine ingressions into the SPB have been mentioned by several authors (Reiche, 1956; Backhaus, 1964; Plumhoff, 1966; Gast, 1991; Gebhardt, 1994; Schneider and Gebhardt, 1995; Legler et al., 2005). But short-term marine ingressions into saline lakes are not easy to recognize in the geological record if the amount of inflowing water is insufficient to establish marine conditions. They will only result in dilution of the brine. Marine fauna will not survive in this ecologically stressed environment long enough to produce abundant fossils. This accounts for the almost complete absence of indicators of marine influence in Upper Rotliegend II-deposits (Late Wordian to Early Wuchiapingian) of the Southern Permian Basin (SPB) of Northwest Europe. Because of the rarity of marine fossils and the minimal marine influence on deposition, these ingressions were often completely overlooked. The aim of the present paper is to attempt to find an alternative to palaeontology for identifying these marine ingressions. Additionally mechanisms that triggered these ingressions and their influence on depositional patterns are addressed. Finally, possible evidence of Palaeogeography, Palaeoclimatology, Palaeoecology 267 (2008) 102–114 ⁎ Corresponding author. Present address: RWE Dea Laboratory Wietze, Geosciences, Industriestr. 2, 29323 Wietze, Germany. Fax: +49 5146/89275. E-mail address: berit.legler@rwe.com (B. Legler). 0031-0182/$ – see front matter © 2008 Elsevier B.V. All rights reserved. doi:10.1016/j.palaeo.2008.06.009 Contents lists available at ScienceDirect Palaeogeography, Palaeoclimatology, Palaeoecology journal homepage: www.elsevier.com/locate/palaeo