Cretaceous Research 65 (2016) 17e24 Contents lists available at ScienceDirect Cretaceous Research journal homepage: www.elsevier.com/locate/CretRes Organic-walled dinoflagellate cyst records from a prospective Turonian e Coniacian (Upper Cretaceous) GSSP, Słupia Nadbrzezna,_ Poland * Kate Olde a, Ian Jarvis a, , Martin Pearce b, a, Ireneusz Walaszczyk c, Bruce Tocher d a Kingston University London, Department of Geography and Geology, Kingston upon Thames, KT1 2EE, UK b Evolution Applied Ltd, 50 Mitchell Way, Upper Rissington, Cheltenham, GL54 2PL, UK c Faculty of Geology, University of Warsaw, Al. wirki i Wigury 93, PL-02-089, Warszawa, Poland d Statoil, 6300 Bridge Point Parkway, Building 2, Suite 500, Austin, TX 78730, USA article info abstract Article history: A river section at Słupia Nadbrzezna,_ central Poland, has been proposed as a candidate Turonian e Received 2 July 2015 Coniacian (Cretaceous) GSSP, in combination with the Salzgitter-Salder quarry section of Lower Saxony, Received in revised form Germany. Results of a high-resolution (25 cm) palynological study of the boundary interval in the Słupia 31 March 2016 Nadbrzezna_ section are presented. Terrestrial palynomorphs are rare; marine organic-walled dinofla- Accepted in revised form 15 April 2016 gellate cysts dominate the palynological assemblage. The dinoflagellate cyst assemblage has a low Available online 16 April 2016 species richness (5e11 per sample; total of 18 species recorded) and diversity (Shannon index H ¼ 0.8 e1.4), dominated by four taxa: Circulodinium distinctum subsp. distinctum; Oligosphaeridium complex; Keywords: Turonian Spiniferites ramosus subsp. ramosus; Surculosphaeridium longifurcatum. Declining proportions of Coniacian O. complex and S. ramosus subsp. ramosus characterise the uppermost Turonian, with an increased GSSP dominance of S. longifurcatum in the lower Coniacian. The Turonian e Coniacian boundary interval in- Palynology cludes an acme of C. distinctum subsp. distinctum in the upper Mytiloides scupini Zone, a dinoflagellate Dinoflagellate cyst cyst abundance maximum in the Cremnoceramus walterdorfensis walterdorfensis Zone, and the highest occurrence of Senoniasphaera turonica in the basal Coniacian lower Cremnoceramus deformis erectus Zone. Most previously reported Turonian e Coniacian boundary dinoflagellate cyst marker species are absent; a shallow-water oligotrophic epicontinental depositional setting, remote from terrestrial influence, likely limited species diversity and excluded many taxa of biostratigraphic value. © 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). 1. Introduction western Wisła river cliff in the village of Słupia Nadbrzezna_ (50.9501N, 21.8078E), situated 150 km SSE of Warsaw. The The Słupia Nadbrzezna_ river cliff section, central Poland, com- exposure exists in a poor state, requiring excavation before study bined with the Salzgitter-Salder quarry of Lower Saxony, Germany, (Walaszczyk et al., 2010), but yields well-preserved inoceramid has been proposed as a composite Global Boundary Stratotype bivalve assemblages. The approximately 10 m section consists of Section and Point (GSSP) for the base of the Coniacian Stage at opoka (siliceous marl) facies with varying proportions of chert 89.75 Ma (Walaszczyk and Wood, 1998; Walaszczyk et al., 2010; (Fig. 2). Ogg et al., 2012). The Słupia Nadbrzezna_ section spans the upper Turonian up- During the Late Cretaceous, Słupia Nadbrzezna_ was located in a permost Mytiloides scupini Zone to the lower Coniacian lowest pelagic carbonate setting on the eastern margin of the Central Cremnoceramus deformis erectus Zone, and provides an expanded European epicontinental basins system (Voigt et al., 2008; Fig. 1). and more complete Turonian e Coniacian boundary record than the The section forms part of the expanded Upper Cretaceous succes- better-exposed Salzgitter-Salder section (Wood et al., 2004; sion of the Middle Wisła (Vistula) River, and is exposed in the Walaszczyk et al., 2010), which was proposed as the base Con- iacian GSSP by the Coniacian Working Group of the Subcommission on Cretaceous Stratigraphy (Kauffman et al., 1996). The proposed * Corresponding author. base of the Coniacian is taken at the lowest occurrence of the E-mail address: [email protected] (I. Jarvis). http://dx.doi.org/10.1016/j.cretres.2016.04.010 0195-6671/© 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). 18 K. Olde et al. / Cretaceous Research 65 (2016) 17e24 Gdańsk Boreal N Sea Mid-Polish TroughWarsaw Salzgitter -Salder Berlin Sudetic Islands Słupia Nadbrzeżna Kraków Rhenish Prague Massif Bohemian Massif Munich Penninic Ocean100 km emergent highs shallow deep basin epicontinental sea basin subject to Late major fault candidate Cretaceous inversion GSSPs Fig. 1. Location of the Słupia Nadbrzezna_ and Salzgitter-Salder candidate GSSP sections and Turonian palaeogeography of central Europe. Map compiled from Voigt et al. (2008). inoceramid bivalve Cremnoceramus deformis erectus (Meek, 1877) 2. Materials and methods [¼ C. rotundatus (sensu Troger,€ 1967 non Fiege, 1930)]. This lies above the lowest occurrence of the ammonite Forresteria (Harleites) Twenty-one samples from the Słupia Nadbrzezna_ section that petrocoriensis (Coquand, 1859), traditionally used as a Coniacian had been collected for stable-isotope analysis (Walaszczyk et al., marker in the stratotype area of the Aquitaine Basin (Kennedy and 2010) were selected for palynological preparation. Splits (20 g) Walaszczyk, 2004; Fig. 3). Inoceramid records indicate condensa- of chipped samples were processed for quantitative palynolog- tion and a minor hiatus at the stage boundary in the strati- ical analysis. Palynomorphs >15 mm were concentrated by a graphically more extensive section at Salzgitter-Salder (Wood et al., commercial processing company (PLS Ltd, Holyhead, UK) using 2004; Walaszczyk et al., 2010); this hiatus provides the rationale for the HCleHF method of Lignum (2009),modified from Lignum using the two sections as a composite GSSP. et al. (2008, ‘Company B’ methodology). Oxidation of the sam- The lithostratigraphy, macrofossil, foraminiferal and nanno- ples was unnecessary due to the low concentration of amor- fossil biostratigraphy and carbon stable-isotope chemo- phous organic matter present. All samples were spiked with stratigraphy of Słupia Nadbrzezna_ and Salzgitter-Salder have been tablets containing the modern spore Lycopodium to allow sta- described by Walaszczyk and Peryt (1998), Walaszczyk and Wood tistically valid quantitative analysis (dinoflagellate cysts per (1998), Kennedy and Walaszczyk (2004), Wood et al. (2004), Lees gram, dpg). (2008) and Walaszczyk et al. (2010). In terms of carbon stable Palynomorph identification and counting was undertaken isotopes, the Turonian e Coniacian boundary lies at an inflection using a Leitz Laborlux S light microscope with a 40Â objective. point from long-term falling to rising d13C values (Voigt and Taxonomic assignments followed Fensome et al. (2008) and Hilbrecht, 1997; Wiese, 1999; Jarvis et al., 2006). Most of the Pearce et al. (2011). Three hundred organic walled dinoflagel- succession at Słupia Nadbrzezna_ represents the upper part of the late cysts (dinocysts) were identified per sample. Broken or par- broad d13C minimum that occurs globally at the Turonian e tial specimens were added to the count only if there was more Coniacian boundary (Wendler, 2013; Jarvis et al., 2015), the Nav- than half of the specimen present. Unidentifiable specimens were igation Carbon Isotope Event (CIE; Fig. 2)ofJarvis et al. (2006). recorded as ‘indeterminate’, and were not included in the count However, carbon and oxygen stable-isotope values from Słupia of 300, but were included when calculating total palynomorphs Nadbrzezna_ show high-amplitude variation with lithology per gram. Following this count, the remainder of the slide was (Figs. 2, 3), indicating that the section has likely been affected by scanned to identify any additional species, which were marked as diagenesis (cf. Walaszczyk et al., 2010). Carbon stable-isotope ‘present’, but in abundances too low to be recorded among the values are around 1‰ lower than those found at an equivalent 300. The presence of any other palynomorphs such as pollen level in Salzgitter-Salder (Fig. 2), offering further evidence of a grains, spores, acritarchs and foraminiferal test linings was also diagenetic overprint. noted. K. Olde et al. / Cretaceous Research 65 (2016) 17e24 19 Stage Zone Height (m)LithologyBed Cci 85 Isomicraster oods) 75 (W (Woods) 73 Inoceramid bivalve ranges b 71 and macrofossil events a 70 (Heinz) 80 (Heinz) 69 Micraster 67 cortestudinarium b 65 a 75 13 63 δ C . hannovrensis (Andert) (Andert) (Andert) (Andert) w Cremnoceramus crassus inconstans 61 Cremnoceramus crassus inconstans C. 60 59 58 (Meek) (Meek) (Meek) 70 57 (Meek) 55 Słupia b 53 Nadbrzeżna a erectus III dc b hannovrensis Cremnoceramus walterdorfensis hannovrensis a 52 51 65 c Lithology Height (m)Zone Stage b 50 a 7 b 49 erectus I 6 a erectus II C. d. erectus Andert Andert 48 5 Coniacian 47 erectus I C. d. erectus Cremnoceramus deformis erectus Cremnoceramus deformis erectus Cremnoceramus deformis erectus 60 Cremnoceramus deformis erectus LO C.d. erectus 46 waltersdorfensis II b 45 4 Cww a Didymotis II Cww Cremnoceramus walterdorfensis waltersdorfensis waltersdorfensis