Carbon and oxygen isotope records of Permian brachiopods from relatively low and high palaeolatitudes: climatic seasonality and evaporation

Abstract

Several brachiopods which belong to the same genus Horridonia of late Early and early Late Permian age in Spitsbergen and Poland, respectively, have been petrographically and geochemically analysed to verify seasonal variation in stable carbon and oxygen isotope values for palaeoclimatological implications. The specimens of Horridonia timanica from Spitsbergen show distinct cyclicity reflective of seasonal pattern, while those of Horridonia horrida from Poland do not. These differences are explained by the fact that the former lived at high palaeolatitudes at the northern margin of the supercontinent Pangaea where the seawater temperature differences between winter and summer seasons were greater, as expressed in the isotopic composition of the skeletal materials. In contrast, the shell growth of Horridonia horrida was subjected to strong evaporative influence by climatic variations in the eastern area of Pangaea.

Depositional environment, ichnological features and oxygenation of Permian to earliest Triassic marine sediments in central Spitsbergen, Svalbard

“…4). This unit is up to 40 m thick (Dallmann et al 1999) and is dominated by bioclastic carbonate banks with a rich fauna of brachiopods, bryozoans and crinoids (Nakrem et al 1992;Ezaki et al 1994;Nielsen et al 2013). The Vøringen Member represents shoreface deposits, which were regarded by Worsley et al (1986) to represent a carbonate barrier sequence that migrated across the restricted marine platform and sabkha environments of the underlying Gipshuken Formation.…”

“…This shift in palaeolatitudes caused a marked change predominantly from warm-water carbonates to cool-water carbonates and spiculites encountered in Arctic Canada, North Greenland, Svalbard and the Barents Sea (Beauchamp & Desrochers 1997;Stemmerik 1997Stemmerik , 2000Stemmerik & Worsley 2005;Blomeier et al 2011;Grundvå g et al 2013;Nielsen et al 2013). The latest Permian and Early Triassic were associated with a temperature rise (Georgieva et al 2011;Sun et al 2012) and are mostly characterized by siliciclastic sediments with few macrofossils at Svalbard (Mørk et al 1999).…”

Saurichthys (Pisces, Actinopterygii) teeth from the Lower Triassic of Spitsbergen, with comments on their stable isotope composition (δ13C and δ18O) and X−ray microtomography

“…This bed represents the up− per part of the Urnetoppen Member of the Vardebukta Formation (Birkenmajer 1964(Birkenmajer , 1977Harland 1997;Dallmann et al 1999). The underlaying strata repre− sent Lower Permian rocks, including brachiopod cherty limestone of the Kapp Starostin Fm (Nakrem et al 1992;Dallmann 1999;Nielsen et al 2013) and cal− careous clastics of the Treskeloden Fm (Birkenmajer and Fedorowski 1980;Birkenmajer 1984;Błażejowski et al 2006;Błażejowski 2009;Nakrem et al 2009). The Vardebukta Formation (Buchan et al 1965) is the oldest lithostratigraphic unit of this rank in the Triassic sequence of the Svalbard archipelago (Fig.…”

First record of catacrinid crinoid from the Lower Permian of Spitsbergen

“…Above the Vøringen Member, abundant trace fossils, such as Zoophycos and Chondrites, indicate low energy as well as oxic to dysoxic bottom waters well below normal wave base (Małkowski 1988;Nakrem 2005). Based on sedimentological, palaeoecological and geochemical evidence (Małkowski and Hoffman 1979;Małkowski 1982Małkowski , 1988Nielsen et al 2013), such depositional conditions were punctuated by the development of a stratified water column where anoxic and sulphidic bottom waters persisted for a short time.…”

“…Detailed petrographical and geochemical investi− gations of several brachiopods belonging to the Late Permian Horridonia and comparisons of specimens from relatively high and low palaeolatitudes were car− ried out to verify seasonal variations in stable carbon and oxygen isotope values for palaeoclimatological implications (Nielsen et al 2013). Analyses of the speci− mens from Spitsbergen show distinct cyclicity, reflecting a seasonal pattern.…”