Strontium Isotope Dating of Spiculitic Permian Strata From Spitsbergen Outcrops and Barents Sea Well‐cores

Abstract

Eight samples of brachiopod shell material have been analyzed for their strontium isotope composition in order to more accurately date Lower to Upper Permian siliceous biogenic strata of Spitsbergen (Kapp Starostin Formation) and the southern Barents Sea (Røye Formation). The results are interpreted as showing a mid‐Artinskian age for the basal Vøringen Member of the Kapp Starostin Formation and a range of late Artinskian to Roadian for the overlying part of this unit. The upper part of the Røye Formation yields ages in the range Roadian to Wuchiapingian. These results are consistent with available biostratigraphic data and confirm the potential of strontium isotope stratigraphy for developing a more accurate chronology of the widespread spiculite deposits that characterize the northern margin of Pangea in late‐Early Permian to Late Permian time and which constitute a potential target for petroleum exploration.

Permian strontium isotope stratigraphy

“…Secular fluctuations of the marine 87 Sr/ 86 Sr ratio, incorporated into authigenic marine sediments and hard parts of fossils, can be used as chemostratigraphic markers for global correlations (e.g. Steuber 2001Steuber , 2003Denison et al 2003;Burla et al 2009;Ehrenberg et al 2010; see also McArthur et al 2012). This application makes use of the observations that seawater has a globally uniform 87 Sr/ 86 Sr ratio, and shows secular drifts of measureable magnitude.…”

Polygonal mounds in the Barents Sea reveal sustained organic productivity towards the P–T boundary

“…Upper Permian detrital banks formed by locally derived bryozoan–echinoderm–spicule fragmental debris have thus been identified on Finnmark and Svalbard (Ehrenberg et al ., , ). They are ?Kungurian to Late Permian in age, and comprise the cold‐water ‘hyalosponge‐bryonoderm’ assemblages of unit L‐9 (Beauchamp, , ) (Fig.…”

“…On Svalbard, detrital banks of locally derived limestones with bryozoan–echinoderm–spicule fragmental debris, crinoids, sponges and brachiopods comprise the majority of the Upper Permian Kapp Starostin Formation (Blendinger et al ., ; Ehrenberg et al ., ). These detrital banks lack the sediment‐baffling or binding mode of accumulation that is typical of Upper Carboniferous–Lower Permian build‐ups (Malkowski and Hoffman, ; Wignall et al ., ; Ehrenberg et al ., , ). Regional seismic and borehole data nevertheless show these detrital banks were capable of forming reliefs of tens of metres on the Permian seafloor (Ehrenberg et al ., ).…”

Paleozoic Carbonates Record the 4D evolution of Salt Domes in the Barents Sea

“…Upper Permian detrital banks formed by locally derived bryozoan-echinoderm-spicule fragmental debris also been identified on Finnmark and Svalbard (Ehrenberg et al, 1998(Ehrenberg et al, , 2010. They comprise ?Kungurian to Late Permian mounds and buildups, and comprise the cold-water 'hyalospongebryonoderm' assemblages that are part of unit L-9.…”