A unique geochemical record at the Permian/Triassic boundary

Holser, William T.; Schönlaub, Hans Peter; Attrep, Moses; Boeckelmann, Klaus; Klein, Peter; Magaritz, Mordeckai; Orth, C. J.; Fenninger, Alois; Jenny, C.; Králík, Martin; Mauritsch, Hermann Johann; Pak, Edwin; Schramm, Josef-Michael; Stattegger, Karl; Schmöller, R.

doi:10.1038/337039a0

Cited by 265 publications

(130 citation statements)

References 39 publications

Supporting

Mentioning

120

Contrasting

Order By: Relevance

“…Because temperatures increased across the P/T boundary (42), the temperature effect tends in the opposite direction from the observed excursion, reducing its apparent magnitude. The amount of warming across the boundary is poorly constrained, but an increase of 5-10°C (43,44) could reduce the fractionation by as much as 0.1-0.2‰ (26,41). Thus, the negative excursion in seawater δ 44∕40 Ca may be somewhat larger than reflected in the raw data.…”

Section: Discussionmentioning

confidence: 90%

Calcium isotope constraints on the end-Permian mass extinction

Payne

Turchyn

Paytan

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

210

164

View full text Add to dashboard Cite

The end-Permian mass extinction horizon is marked by an abrupt shift in style of carbonate sedimentation and a negative excursion in the carbon isotope (δ 13 C) composition of carbonate minerals. Several extinction scenarios consistent with these observations have been put forward. Secular variation in the calcium isotope (δ 44∕40 Ca) composition of marine sediments provides a tool for distinguishing among these possibilities and thereby constraining the causes of mass extinction. Here we report δ 44∕40 Ca across the Permian-Triassic boundary from marine limestone in south China. The δ 44∕40 Ca exhibits a transient negative excursion of ∼0.3‰ over a few hundred thousand years or less, which we interpret to reflect a change in the global δ 44∕40 Ca composition of seawater. CO 2 -driven ocean acidification best explains the coincidence of the δ 44∕40 Ca excursion with negative excursions in the δ 13 C of carbonates and organic matter and the preferential extinction of heavily calcified marine animals. Calcium isotope constraints on carbon cycle calculations suggest that the average δ 13 C of CO 2 released was heavier than −28‰ and more likely near −15‰; these values indicate a source containing substantial amounts of mantle-or carbonatederived carbon. Collectively, the results point toward Siberian Trap volcanism as the trigger of mass extinction.

show abstract

Section: Discussionmentioning

confidence: 90%

Calcium isotope constraints on the end-Permian mass extinction

Payne

Turchyn

Paytan

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

210

164

View full text Add to dashboard Cite

show abstract

“…1L) (11) and Late Permian (Fig. 1E) (12), began at about the time of the associated major extinction, when a global climate shift occurred, and peaked slightly later. The high-resolution record for the Eocene/ Oligocene transition shows the associated δ 13 C excursion to have begun slightly (<10;000 y) after the associated δ 18 O excursion (13).…”

Section: Resultsmentioning

confidence: 99%

Relation of Phanerozoic stable isotope excursions to climate, bacterial metabolism, and major extinctions

Stanley

2010

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Conspicuous global stable carbon isotope excursions that are recorded in marine sedimentary rocks of Phanerozoic age and were associated with major extinctions have generally paralleled global stable oxygen isotope excursions. All of these phenomena are therefore likely to share a common origin through global climate change. Exceptional patterns for carbon isotope excursions resulted from massive carbon burial during warm intervals of widespread marine anoxic conditions. The many carbon isotope excursions that parallel those for oxygen isotopes can to a large degree be accounted for by the Q10 pattern of respiration for bacteria: As temperature changed along continental margins, where ∼90% of marine carbon burial occurs today, rates of remineralization of isotopically light carbon must have changed exponentially. This would have reduced organic carbon burial during global warming and increased it during global cooling. Also contributing to the δ 13 C excursions have been release and uptake of methane by clathrates, the positive correlation between temperature and degree of fractionation of carbon isotopes by phytoplankton at temperatures below ∼15°, and increased phytoplankton productivity during "icehouse" conditions. The Q10 pattern for bacteria and climate-related changes in clathrate volume represent positive feedbacks for climate change. paleoclimatology | paleoceanography M any possible explanations have been advanced for one or more of the abrupt excursions in the δ 13 C of marine carbonates and organic matter that have been documented in the geologic record (see Fig. 1). Most of these hypotheses have focused on factors that change the global rate of burial of organic carbon, which is isotopically light: changes in upwelling and primary productivity; fluctuations of sea level; changes in ocean dynamics, including ones affecting the extent of anoxic conditions; changes in carbonate weathering rates; release of methane from sediments; changes in nutrient input from the land to the oceans; volcanic degassing; and release of isotopically light CO 2 from the deep sea (for literature, see SI Text, Section I). Given the strong positive correlation between δ 13 C and δ 18 O excursions in shallow marine sediments (Fig. 1), however, parsimony suggests that one or more unifying explanations should be sought to explain all of these phenomena.Missing from previous explanations for geologically brief δ 13 C excursions has been a consideration of the role of microbial processes, even though microbes have an enormous global biomass and play a prominent role in the exogenic carbon cycle. Particulate organic matter in ecosystems has three possible fates: It can be consumed by primary consumers, decomposed by bacteria (or fungi, in the case of lignocellulose), or buried. The relative importance of these fates varies from place to place and time to time. For example, carbon burial on land increased markedly during the late Paleozoic, when coal swamps became widespread (1). In the oceanic realm beyond continental rises, organ...

show abstract

“…5). The preglacial ␦ 13 C carb plunge is correlated with a negative Ce/Ce * shift of ∼0.4, suggesting reducing conditions (e.g., Holser et al, 1989;Shields et al, 1997), which is consistent with their low (<2) Th/U values (Wignall and Twitchett, 1996;Wignall et al, 2007). In contrast, the lower postglacial plunge in ␦ 13 C carb , immediately above the diamictite (D II), is correlated with a significant positive Ce/Ce * shift of ∼1.5 (Fig.…”

Section: Redox Conditionsmentioning

confidence: 48%

Oceanic redox conditions in the Late Mesoproterozoic recorded in the upper Vazante Group carbonates of São Francisco Basin, Brazil: Evidence from stable isotopes and REEs

Azmy

Sylvester

Oliveira³

2009

Precambrian Research

View full text Add to dashboard Cite

a b s t r a c tThe Vazante Group consists of a late Mesoproterozoic (∼1.0-1.1 Ga) carbonate-dominated marine platform sequence in east-central Brazil. The upper part of the sequence consists of a glaciomarine diamictite unit overlain by a cap carbonate. The ␦ 13 C profile of the upper Vazante shows significant negative plunges, one preglacial (drop of ∼5.5‰ VPDB) and two postglacial (drops of ∼9 and 5‰VPDB, respectively). The C-isotope plunge in the preglacial carbonates is correlated with low Th/U ratios (0.1-1.4) and a negative Ce/Ce* shift (∼0.4), suggesting deposition under relative reducing conditions. In contrast, the C-isotope plunges in the postglacial carbonates are associated with high Th/U ratios (>2) and positive Ce/Ce* shifts (up to ∼1.5), thus reflecting oxidizing conditions. Variations in the redox conditions of the late Mesoproterozoic ocean, reflected by changes in the Th/U and Ce/Ce* ratios, are likely attributable to a combination of both global and local climatic and oceanographic changes, similar to what has been inferred for the Neoproterozoic oceans.

show abstract

A unique geochemical record at the Permian/Triassic boundary

Cited by 265 publications

References 39 publications

Calcium isotope constraints on the end-Permian mass extinction

Calcium isotope constraints on the end-Permian mass extinction

Relation of Phanerozoic stable isotope excursions to climate, bacterial metabolism, and major extinctions

Oceanic redox conditions in the Late Mesoproterozoic recorded in the upper Vazante Group carbonates of São Francisco Basin, Brazil: Evidence from stable isotopes and REEs

Contact Info

Product

Resources

About