An abrupt extinction in the Middle Permian (Capitanian) of the Boreal Realm (Spitsbergen) and its link to anoxia and acidification David P.G. Bond1,†, Paul B. Wignall2, Michael M. Joachimski3, Yadong Sun3,4, Ivan Savov2, Stephen E. Grasby5,6, Benoit Beauchamp6, and Dierk P.G. Blomeier7 1Department of Geography, Environment and Earth Sciences, University of Hull, Hull, HU6 7RX, United Kingdom 2School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom 3Geozentrum Nordbayen, Universität Erlangen-Nürnberg, Schlossgarten 5, 91054 Erlangen, Germany 4State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, 388 Lumo Road, Wuhan, 470073, Hubei Province, P.R. China 5Geological Survey of Canada, 3303 33rd Street N.W., Calgary, Alberta, T2L 2A7, Canada 6Department of Geoscience, University of Calgary, 2500 University Drive N.W., Calgary Alberta, T2N 1N4, Canada 7Norwegian Polar Institute, Fram Centre, 9296 Tromsø, Norway ABSTRACT mass extinction events; it is regarded as either sil ranges in the Kapp Starostin Formation of one of the greatest of all Phanerozoic crises, Spitsbergen, a Permian-aged mixed spiculite The controversial Capitanian (Middle ranking alongside the “Big 5” (Stanley and chert-carbonate unit that formed in cool, shelf Permian, 262 Ma) extinction event is only Yang, 1994; Bond et al., 2010a), or, in a funda- seas of the Boreal Ocean (Ehrenberg et al., known from equatorial latitudes, and conse- mentally different appraisal, it is viewed not as 2001; Stemmerik and Worsley, 2005; Blomeier quently its global extent is poorly resolved. a mass extinction but as a protracted and gradu- et al., 2013; Dustira et al., 2013). We assess the We demonstrate that there were two, severe ally attained low point in Permian diversity role of redox changes during this interval using extinctions amongst brachiopods in northern (Yang et al., 2000; Clapham et al., 2009; Groves a combination of petrographic and geochemical Boreal latitudes (Spitsbergen) in the Middle and Wang, 2013). Until now, all detailed studies approaches. The precise age of the formation is to Late Permian, separated by a recovery have focused on equatorial sections, especially unclear, and we investigate this issue with a car- phase. New age dating of the Spitsbergen those of South China, where the extinction was bon and strontium isotope chemostratigraphic strata (belonging to the Kapp Starostin For- first recognized as an especially severe crisis. study and through comparison with better-dated mation), using strontium isotopes and d13C There, fusulinacean foraminifers and brachio- East Greenland successions. trends and comparison with better-dated pods lost 82% and 87% of species, respectively sections in Greenland, suggests that the first (Jin et al., 1994; Shen and Shi, 1996; Bond et al., STUDY SECTIONS AND METHODS crisis occurred in the Capitanian. This age 2010a). The South China marine losses coin- assignment indicates that this Middle Perm- cided with the eruption of the Emeishan flood We logged and sampled the Kapp Starostin ian extinction is manifested at higher lati- basalt province in the southwest of the coun- Formation over three field seasons at its epony- tudes. Redox proxies (pyrite framboids and try (Fig. 1; Wignall et al., 2009a), supporting a mous type section near Festningen in central trace metals) show that the Boreal crisis co- causal link between the two phenomena, but it Spitsbergen, and three further sections at Van incided with an intensification of oxygen de- is unclear if this regional crisis was also a global Keulenhamna, Eholmen, and Forkastningsdalen pletion, implicating anoxia in the extinction event. There are several purported kill mecha- in southern Spitsbergen (Fig. 2). We examined scenario. The widespread and near-total loss nisms but no consensus, and there are also ques- the Kapp Starostin Formation in the field for its of carbonates across the Boreal Realm also tions about the nature of the subsequent Late facies and fossil content, identifying the bra- suggests a role for acidification in the crisis. Permian postextinction interval (Bond et al., chiopod and bivalves to genus or species level The recovery interval saw the appearance of 2010a). Did marine biota recover from a Capita- (see supplemental text: taxonomy1), and we took new brachiopod and bivalve taxa alongside nian mass extinction (Bond and Wignall, 2009; several hundred samples for thin section and survivors, and an increased mollusk domi- Wignall et al., 2012) before their final coup-de- geochemical analyses. nance, resulting in an assemblage reminis- grâce in the latest Permian, or did they undergo The Kapp Starostin Formation consists of Kun- cent of younger Mesozoic assemblages. The gradual diversity decline in the run-up to the gurian to latest Permian strata that were depos- subsequent end-Permian mass extinction ter- Permian-Triassic mass extinction, character- ited on an epicontinental shelf at the northeastern minated this Late Permian radiation. ized by a slow transition to mixed faunas with margin of Pangea (Blomeier et al., 2013). This Paleozoic and Mesozoic affinities (Clapham and was part of an extensive sea that stretched from INTRODUCTION Bottjer, 2007)? Arctic Canada (Sverdrup Basin) and Greenland The status and cause of the Capitanian crisis The Middle Permian (Capitanian Stage) mass are based on evidence from tropical (Tethyan) 1GSA Data Repository item 2015139, DR1 text extinction is among the least understood of all latitudes, while little data exist from higher (taxonomy), and Figures DR1–DR2, is available at latitudes. Here, we redress this imbalance with http://www.geosociety.org/pubs/ft2015.htm or by re- †[email protected] a detailed evaluation of Boreal marine fos- quest to [email protected]. GSA Bulletin; September/October 2015; v. 127; no. 9/10; p. 1411–1421; doi: 10.1130/B31216.1; 8 figures; 1 table; Data Repository item 2015139; published online 14 April 2015. For permission to copy, contact [email protected] 1411 © 2015 Geological Society of America; Gold Open Access: This paper is published under the terms of the CC-BY license. Bond et al. IUGS 87 86 Period & Stages Conodont Tethyan events Tethyan Capitanian Global Sr/ Sr Series Zones Paleomag carbon isotopes record 252.2 Changhsingian n 254.1 C. orientalis n C. transcaucasia C. guangyuanensis Wuchiapingian E PERMIAN C. leveni Lopingia AT C. asymmetrica C. dukouensis GLB excursion C. postbitteri post. 259.8 C. postbitteri hong. Ma J. granti iassic mixed polarity superchro Emeishan Tr Capitanian J. prexuan / xuan volcanism NL J. altudaensis Capitanian J. shannoni excursion Tethyan Permian- J. postserrata Capitanian 265.1 extinction level -3 -2 -1 0123456 Wordian Illawara 13 Guadalupian Reversal δ C(carb) ‰ (pdb) 268.8 MIDDLE PERMIA Roadian Kiaman superchron 272.3 0.7072 0.7070 0.7068 87Sr/86Sr Figure 1. Summary of Middle to Late Permian stratigraphy, Capitanian and Wuchiapingian conodont zones, 13 87 86 the Tethyan d Ccarb record (after Wang et al., 2004; Bond et al., 2010b), the global Sr/ Sr curve (from Korte et al., 2006), and the International Union of Geological Sciences (IUGS) paleomagnetostratigraphic “bar code,” in which periods of normal and reversed polarity are shown as black and white intervals respectively. Ages of stage boundaries after Cohen et al. (2013). Placement of the Illawara reversal is after Isozaki (2009). Abbreviations for conodont zones and stage names as follows: J.—Jinogondolella; C.—Clarkina; prexuan/xuan—prexuanhanensis/ xuanhanensis; hong—hongshuensis; post—postbitteri; GLB—Guadalupian/Lopingian boundary. The timing of Emeishan volcanism and the low-latitude Capitanian mass extinction is based on Wignall et al. (2009a). pdb— Peedee belemnite. (Wandel Sea Basin) in the west, through Svalbard volcanism in the Jinogondolella altudaensis a Finnigan Mat Delta+XL mass spectrometer and the Barents Sea (Finnmark Platform, Stap- conodont zone (Fig. 1; Wignall et al., 2009a). A interfaced with a Costech 4010 elemental ana- 13 pen High), to Russia (Timan-Pechora Basin) in younger and smaller negative shift in d Ccarb is lyzer, with standards run every fifth sample. the east (Stemmerik and Worsley, 2005). The also known from the Capitanian-Wuchiapingian Combined analytical and sampling error for 13 shelf was located at ~45°N in the Middle to Late Stage boundary (the Guadalupian-Lopingian d Corg is ±0.2‰ (1s). In Erlangen (curves of M. 13 Permian. The Kapp Starostin Formation contains Series boundary; Fig. 1) in China and Japan Joachimski and Y. Sun), d Corg was determined cool-water Boreal faunas that include abundant (Fig. 1; Wang et al., 2004; Isozaki et al., 2007). with an elemental analyzer (CE 1110) con- siliceous sponges, brachiopods, and bryozoans The Middle to Late Permian d13C chemostrati- nected online to a ThermoFisher Delta V Plus (e.g., Gobbett, 1964; Kobayashi, 1997; Shen graphic record can be compared with the mass spectrometer, and accuracy and reproduc- and Shi, 2004). The formation attains its great- 87Sr/86Sr record of Permian seawater that derives ibility of the analyses were checked by replicate est thickness in central Spitsbergen, where it from brachiopod shells (McArthur et al., 2001; analyses of international (USGS 40) or labo- reaches >400 m thick, and thins southwards, Korte et al., 2006). The 87Sr/86Sr values decline ratory standards. Reproducibility of replicate eventually pinching out at the Sørkapp-Hornsund to a Phanerozoic low point of ~0.70685 in the standard analyses was ±0.07‰ (1s). Values are High (Dallmann, 1999). We logged and sampled late Capitanian (Fig. 1; Korte et al., 2006). This reported in conventional d notation in permil the upper ~220 m in the southern locations, and has been attributed to minimal runoff of radio- relative to Vienna Peedee belemnite (V-PDB). the upper 90 m at Kapp Starostin (Figs. 3 and 4; genic Sr from the highly arid Pangean super- Our Boreal strontium isotope record was gen- supplemental Fig. DR1 [see footnote 1]). continent (Gibbs et al., 1999). Together, the C erated from brachiopod shells screened using and Sr isotopic records provide a chemostrati- cathodoluminescence (Fig.