Ocean sulfate scarcity as a pre-condition for Large Igneous Province driven mass extinction

Author(s):  
Robert J. Newton ◽  
Tianchen He ◽  
Jacopo Dal Corso ◽  
Paul Wignall ◽  
Ben Mills ◽  
...  

<p>Records of sulfur cycling during mass extinction events increasingly show that they are associated with rapid shifts in the sulfur isotope composition of seawater indicative of low concentrations of ocean sulfate [1-4]. These events are also often associated with the spread of anoxic conditions in the marine realm. We propose a feedback mechanism whereby the production of methane in marine sediments increases in proportion to decreasing sulfate and consumes bottom water oxygen, thus acting as a positive feedback on spread of anoxic waters. This can be further amplified via increased weathering or recycled fluxes of phosphate enhancing productivity [e.g. 5], the effects of increasing temperature on the rate of methanogenesis and the additional suppression of marine sulfate via increased pyrite burial.</p><p>We propose that sulfate drawdown occurs prior to climate forcing and other extinction drivers imposed by large igneous province (LIP) eruption. The likely mechanism for the drawdown of sulfate prior to these extinction is the removal of sulfate from the oceans as gypsum in evaporite deposits. Several large mid-Phanerozoic mass extinctions have clear evidence of increased evaporite deposition prior to, or approximately coincidental with LIP eruption and extinction.</p><p>If this idea is correct, the biological impact of a LIP will partly depend on the sulfate status of the ocean at the time of its eruption, and may at least partly explain the observation that whilst many mass extinctions are associated temporally with a LIP, not all LIPs seem to cause mass extinctions.</p><p>1. Newton, R.J., et al., Geology, 2011. 39(1): p. 7-10.</p><p>2. Song, H., et al., Geochimica et Cosmochimica Acta, 2014. 128(0): p. 95-113.</p><p>3. Witts, J.D., et al., Geochimica et Cosmochimica Acta, 2018. 230: p. 17-45.</p><p>4. He, T., et al., Science Advances, 2020. 6(37): p. eabb6704.</p><p>5. Schobben, M., et al., Nature Geoscience, 2020. </p>

2015 ◽  
Vol 153 (2) ◽  
pp. 285-297 ◽  
Author(s):  
STEPHEN E. GRASBY ◽  
BENOIT BEAUCHAMP ◽  
DAVID P.G. BOND ◽  
PAUL B. WIGNALL ◽  
HAMED SANEI

AbstractStrata of Permian – Early Triassic age that include a record of three major extinction events (Capitanian Crisis, Latest Permian Extinction and the Smithian/Spathian Extinction) were examined at the Festningen section, Spitsbergen. Over thec. 12 Ma record examined, mercury in the sediments shows relatively constant background values of 0.005–0.010 μg g–1. However, there are notable spikes in Hg concentration over an order of magnitude above background associated with the three extinctions. The Hg/total organic carbon (TOC) ratio shows similar large spikes, indicating that they represent a true increase in Hg loading to the environment. We argue that these represent Hg loading events associated with enhanced Hg emissions from large igneous province (LIP) events that are synchronous with the extinctions. The Hg anomalies are consistent across the NW margin of Pangea, indicating that widespread mercury loading occurred. While this provides utility as a chemostratigraphic marker the Hg spikes may also indicate loading of toxic metals to the environment, a contributing cause to the mass extinction events.


2021 ◽  
Vol 288 (1960) ◽  
Author(s):  
Pedro M. Monarrez ◽  
Noel A. Heim ◽  
Jonathan L. Payne

Whether mass extinctions and their associated recoveries represent an intensification of background extinction and origination dynamics versus a separate macroevolutionary regime remains a central debate in evolutionary biology. The previous focus has been on extinction, but origination dynamics may be equally or more important for long-term evolutionary outcomes. The evolution of animal body size is an ideal process to test for differences in macroevolutionary regimes, as body size is easily determined, comparable across distantly related taxa and scales with organismal traits. Here, we test for shifts in selectivity between background intervals and the ‘Big Five’ mass extinction events using capture–mark–recapture models. Our body-size data cover 10 203 fossil marine animal genera spanning 10 Linnaean classes with occurrences ranging from Early Ordovician to Late Pleistocene (485–1 Ma). Most classes exhibit differences in both origination and extinction selectivity between background intervals and mass extinctions, with the direction of selectivity varying among classes and overall exhibiting stronger selectivity during origination after mass extinction than extinction during the mass extinction. Thus, not only do mass extinction events shift the marine biosphere into a new macroevolutionary regime, the dynamics of recovery from mass extinction also appear to play an underappreciated role in shaping the biosphere in their aftermath.


Paleobiology ◽  
2007 ◽  
Vol 33 (3) ◽  
pp. 435-454 ◽  
Author(s):  
Andrew Z. Krug ◽  
Mark E. Patzkowsky

AbstractUnderstanding what drives global diversity requires knowledge of the processes that control diversity and turnover at a variety of geographic and temporal scales. This is of particular importance in the study of mass extinctions, which have disproportionate effects on the global ecosystem and have been shown to vary geographically in extinction magnitude and rate of recovery.Here, we analyze regional diversity and turnover patterns for the paleocontinents of Laurentia, Baltica, and Avalonia spanning the Late Ordovician mass extinction and Early Silurian recovery. Using a database of genus occurrences for inarticulate and articulate brachiopods, bivalves, anthozoans, and trilobites, we show that sampling-standardized diversity trends differ for the three regions. Diversity rebounded to pre-extinction levels within 5 Myr in the paleocontinent of Laurentia, compared with 15 Myr or longer for Baltica and Avalonia. This increased rate of recovery in Laurentia was due to both lower Late Ordovician extinction rates and higher Early Silurian origination rates relative to the other continents. Using brachiopod data, we dissected the Rhuddanian recovery into genus origination and invasion. This analysis revealed that standing diversity in the Rhuddanian consisted of a higher proportion of invading taxa in Laurentia than in either Baltica or Avalonia. Removing invading genera from diversity counts caused Rhuddanian diversity to fall in Laurentia. However, Laurentian diversity still rebounded to pre-extinction levels within 10 Myr of the extinction event, indicating that genus origination rates were also higher in Laurentia than in either Baltica or Avalonia. Though brachiopod diversity in Laurentia was lower than in the higher-latitude continents prior to the extinction, increased immigration and genus origination rates made it the most diverse continent following the extinction. Higher rates of origination in Laurentia may be explained by its large size, paleogeographic location, and vast epicontinental seas. It is possible that the tropical position of Laurentia buffered it somewhat from the intense climatic fluctuations associated with the extinction event, reducing extinction intensities and allowing for a more rapid rebound in this region. Hypotheses explaining the increased levels of invasion into Laurentia remain largely untested and require further scrutiny. Nevertheless, the Late Ordovician mass extinction joins the Late Permian and end-Cretaceous as global extinction events displaying an underlying spatial complexity.


Extinctions are not biologically random: certain taxa or functional/ecological groups are more extinction-prone than others. Analysis of molluscan survivorship patterns for the end-Cretaceous mass extinctions suggests that some traits that tend to confer extinction resistance during times of normal (‘background’) levels of extinction are ineffectual during mass extinction. For genera, high species-richness and possession of widespread individual species imparted extinction-resistance during background times but not during the mass extinction, when overall distribution of the genus was an important factor. Reanalysis of Hoffman’s (1986) data ( Neues Jb. Geol. Palaont. Abh. 172, 219) on European bivalves, and preliminary analysis of a new northern European data set, reveals a similar change in survivorship rules, as do data scattered among other taxa and extinction events. Thus taxa and adaptations can be lost not because they were poorly adapted by the standards of the background processes that constitute the bulk of geological time, but because they lacked - or were not linked to - the organismic, species-level or clade-level traits favoured under mass-extinction conditions. Mass extinctions can break the hegemony of species-rich, well-adapted clades and thereby permit radiation of taxa that had previously been minor faunal elements; no net increase in the adaptation of the biota need ensue. Although some large-scale evolutionary trends transcend mass extinctions, post-extinction evolutionary pathways are often channelled in directions not predictable from evolutionary patterns during background times.


2018 ◽  
Vol 285 (1886) ◽  
pp. 20181191 ◽  
Author(s):  
Rafał Nawrot ◽  
Daniele Scarponi ◽  
Michele Azzarone ◽  
Troy A. Dexter ◽  
Kristopher M. Kusnerik ◽  
...  

Stratigraphic patterns of last occurrences (LOs) of fossil taxa potentially fingerprint mass extinctions and delineate rates and geometries of those events. Although empirical studies of mass extinctions recognize that random sampling causes LOs to occur earlier than the time of extinction (Signor–Lipps effect), sequence stratigraphic controls on the position of LOs are rarely considered. By tracing stratigraphic ranges of extant mollusc species preserved in the Holocene succession of the Po coastal plain (Italy), we demonstrated that, if mass extinction took place today, complex but entirely false extinction patterns would be recorded regionally due to shifts in local community composition and non-random variation in the abundance of skeletal remains, both controlled by relative sea-level changes. Consequently, rather than following an apparent gradual pattern expected from the Signor–Lipps effect, LOs concentrated within intervals of stratigraphic condensation and strong facies shifts mimicking sudden extinction pulses. Methods assuming uniform recovery potential of fossils falsely supported stepwise extinction patterns among studied species and systematically underestimated their stratigraphic ranges. Such effects of stratigraphic architecture, co-produced by ecological, sedimentary and taphonomic processes, can easily confound interpretations of the timing, duration and selectivity of mass extinction events. Our results highlight the necessity of accounting for palaeoenvironmental and sequence stratigraphic context when inferring extinction dynamics from the fossil record.


2018 ◽  
Vol 285 (1878) ◽  
pp. 20180232 ◽  
Author(s):  
Ádám T. Kocsis ◽  
Carl J. Reddin ◽  
Wolfgang Kiessling

Mass extinctions are defined by extinction rates significantly above background levels and have had substantial consequences for the evolution of life. Geographically selective extinctions, subsequent originations and species redistributions may have changed global biogeographical structure, but quantification of this change is lacking. In order to assess quantitatively the biogeographical impact of mass extinctions, we outline time-traceable bioregions for benthic marine species across the Phanerozoic using a compositional network. Mass extinction events are visually recognizable in the geographical depiction of bioregions. The end-Permian extinction stands out with a severe reduction of provinciality. Time series of biogeographical turnover represent a novel aspect of the analysis of mass extinctions, confirming concentration of changes in the geographical distribution of benthic marine life.


2021 ◽  
Author(s):  
Ingrid Urban ◽  
Sylvain Richoz

<p>The End-Triassic Mass Extinction (ETME) is one of the five major mass extinctions of the Phanerozoic. The deposition of ooids is atypically high in the direct aftermath of major extinction events, including the ETME. Ooids were intensively investigated both petrographically and sedimentologically in the past decades; but only recently their potentialities as archives for the original chemical composition of the oceans where they formed, have gained awareness. Here we present stratigraphical, sedimentological and geochemical aspects for a mid-Norian-Hettangian section from the Emirates.</p><p>Petrographic analyses provided a detailed morphological classification of post-ETME coated grains, supported by point counting of two isochronous geological sections. FE-SE-EDX imaging unraveled peculiar µm-scale features linked to morphology, diagenesis and biotic interaction in the cortex. LA-ICP-MS analyses were performed for specific major and trace elements. Post-extinction oolites show high variability in size and development of the cortex. They range from small (~ 300 µm) and superficial coating, to bigger (up to 800 µm) and well developed. The degree of micritization highlights different oxic conditions in the diagenetic environment. LA-ICP-MS analyses give insights into seawater redox conditions during ooids formation, siliciclastic contamination, diagenetic processes and the role of bacterial strain in shaping the ooids. Petrographical and geochemical data point out to a calcitic deposition of these ooids as odd with the general consideration that the Late Triassic to Early Jurassic was part of the Aragonite sea. This has major implication on the understanding of the carbonate saturation in the oceans just after the mass-extinction and on the interpretation of several proxies as the C and Ca isotope-system.</p><p> </p><p> </p>


2018 ◽  
Vol 115 (26) ◽  
pp. 6596-6601 ◽  
Author(s):  
Theodore R. Them ◽  
Benjamin C. Gill ◽  
Andrew H. Caruthers ◽  
Angela M. Gerhardt ◽  
Darren R. Gröcke ◽  
...  

For this study, we generated thallium (Tl) isotope records from two anoxic basins to track the earliest changes in global bottom water oxygen contents over the Toarcian Oceanic Anoxic Event (T-OAE; ∼183 Ma) of the Early Jurassic. The T-OAE, like other Mesozoic OAEs, has been interpreted as an expansion of marine oxygen depletion based on indirect methods such as organic-rich facies, carbon isotope excursions, and biological turnover. Our Tl isotope data, however, reveal explicit evidence for earlier global marine deoxygenation of ocean water, some 600 ka before the classically defined T-OAE. This antecedent deoxygenation occurs at the Pliensbachian/Toarcian boundary and is coeval with the onset of initial large igneous province (LIP) volcanism and the initiation of a marine mass extinction. Thallium isotopes are also perturbed during the T-OAE interval, as defined by carbon isotopes, reflecting a second deoxygenation event that coincides with the acme of elevated marine mass extinctions and the main phase of LIP volcanism. This suggests that the duration of widespread anoxic bottom waters was at least 1 million years in duration and spanned early to middle Toarcian time. Thus, the Tl data reveal a more nuanced record of marine oxygen depletion and its links to biological change during a period of climatic warming in Earth’s past and highlight the role of oxygen depletion on past biological evolution.


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