High-precision timeline for Earth’s most severe extinction

Burgess, Seth D.; Bowring, Samuel A.; Shen, Shu-zhong

doi:10.1073/pnas.1317692111

Cited by 582 publications

(508 citation statements)

References 60 publications

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“…As a consequence, the zonation established here confirms the empirical scheme previously established by The duration of each UA-zone can be estimated using the latest high-precision single zircon U-Pb ages obtained from South China. An age of 251.88 ± 0.031 Ma for the Permian-Triassic boundary has been recently proposed by Burgess et al (2014). An age of 251.22 ± 0.2 Ma for the early Smithian Kashmirites kapila beds (corresponding here to SM-5 according to Brühwiler et al, 2010b) is provided by Galfetti et al (2007b).…”

Section: Biochronologymentioning

confidence: 94%

High-resolution biochronology and diversity dynamics of the Early Triassic ammonoid recovery: The Dienerian faunas of the Northern Indian Margin

Ware

Bucher

Brayard

et al. 2015

Palaeogeography, Palaeoclimatology, Palaeoecology

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A new high resolution biozonation based on the Unitary Association (UA) method is constructed for the Dienerian ammonoid succession of the Northern Indian Margin. It includes 12 UA-zones and leads to the subdivision of the Dienerian into three parts (early, middle and late). The corresponding diversity analyses, coupled with results previously obtained for the early Smithian ammonoids of the same regions, highlight the four following phases: (1) a first modest peak of diversity in the earlyDienerian; (2) a very low diversity persisting throughout the middle Dienerian; (3) a slow increase of diversity during the late Dienerian, and (4) a marked diversification in the early Smithian. Turnover rates are very high during this entire time interval, and the boundaries between early-middle and middle-late Dienerian are emphasized by complete renewals of the ammonoid faunas. The low diversity values in the middle and early late Dienerian are concomitant with an anoxic event on outer continental shelves and coincide with warmer temperatures than those of the early Dienerian and early Smithian. This diversity pattern stands in strong contrast with the credo of a protracted or stepwise recovery following the end-Permian mass extinction. Together with the end-Smithian extinction, the middle and early late Dienerian diversity crises were likely both radical setbacks in the recovery of Early Triassic ammonoids. However, these two diversity crises do not necessarily imply identical environmental triggers that ultimately led to anoxic bottom waters on outer continental platforms in both cases.

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Section: Biochronologymentioning

confidence: 94%

High-resolution biochronology and diversity dynamics of the Early Triassic ammonoid recovery: The Dienerian faunas of the Northern Indian Margin

Ware

Bucher

Brayard

et al. 2015

Palaeogeography, Palaeoclimatology, Palaeoecology

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“…Zircon was separated at the Massachusetts Institute of Technology (MIT) using conventional heavy liquid techniques. Uranium and Pb isotopic data were obtained using a VG Sector 54 and IsotopX X-62 mass spectrometers at MIT using analytical procedures from Burgess et al (2013). Whole rock Nd, Sr and Pb isotopic data from these samples were obtained at the University of Colorado, Boulder using analytical procedures outlined by Farmer et al (1991).…”

Section: Samples and Analytical Techniquesmentioning

confidence: 99%

Deep crustal anatexis, magma mixing, and the generation of epizonal plutons in the Southern Rocky Mountains, Colorado

Jacob

Farmer

Buchwaldt

et al. 2015

Contrib Mineral Petrol

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differentiated versions of the silicic melts parental to the Mt. Cumulus stock. Zircon U-Pb geochronology further reveals that the Mt. Richthofen stock was incrementally emplaced over a time interval from at least 28.975 ± 0.020 to 28.742 ± 0.053 Ma. Magma mixing could have occurred either in situ in the upper crust during basaltic underplating and remelting of an antecedent, incrementally emplaced, silicic intrusive body, or at depth in the lower crust prior to periodic magma ascent and emplacement in the shallow crust. Overall, the two stocks demonstrate that magmatism associated with the Never Summer igneous complex was fundamentally bimodal in composition. Highly silicic anatectic melts of the mafic lower crust and basaltic, mantle-derived magmas were the primary melts in the magma system, with mixing of the two producing intermediate composition magmas such as those from which Mt. Richthofen stock was constructed.

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“…The excellent preservation of the associated vertebrate assemblages has led to a large library of published faunal information, complemented by palynological data, that has been extrapolated globally to understand the patterns of tetrapod extinctions and their timing relative to the end-Permian marine extinction at ca. 252 Ma (Burgess et al, 2014;Lucas, 2010;Mundil et al, 2004;Shen et al, 2011;Ward et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

“…The Permian-Triassic boundary (PTB) is defined by marine conodont assemblages, and has a corresponding age of 251.9 ± 0.0 Ma determined from high resolution U-Pb TIMS (zircon) dating of ash beds from the Meishan section in south China (Burgess et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Refining the chronostratigraphy of the Karoo Basin, South Africa: magnetostratigraphic constraints support an early Permian age for the Ecca Group

Belica¹,

Tohver²,

Poyatos‐Moré

et al. 2017

Geophysical Journal International

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Summary:The Beaufort Group of the Karoo Basin, South Africa provides an important chrono-and biostratigraphic record of vertebrate turnovers that have been attributed to the End-Permian mass extinction events at ca. 252 Ma and ca. 260 Ma. However, an unresolved controversy exists over the age of the Beaufort Group due to a large dataset of published U-Pb SHRIMP zircon results that indicate a ca. 274-250 Ma age range for deposition of the underlying Ecca Group. This age range requires the application of a highly diachronous sedimentation model to the Karoo Basin stratigraphy and is not supported by published paleontologic and palynologic data. This study tested the strength of these U-Pb isotopic datasets using a magnetostratigraphic approach. Here we present a composite ~1500 m section through a large part of the Ecca Group from the Tanqua depocentre, located in the southwestern segment of the Karoo Basin. After the removal of two normal polarity overprints, a likely primary magnetic signal was isolated at temperatures above 450°C. This section is restricted to a reverse polarity, indicating that it formed during the Kiaman Reverse Superchron (ca. 318-265 Ma), a distinctive magnetostratigraphic marker for Early−Middle Permian rocks. The Ecca Group has a corresponding paleomagnetic pole at 40.8°S, 77.4°E (A95 = 5.5°). UPb SHRIMP ages on zircons are presented here for comparison with prior isotopic studies of the Ecca Group. A weighted mean U-Pb age of 269.5 ± 1.2 Ma was determined from a volcanic ash bed located in the uppermost Tierberg Formation sampled from the OR1 research core. The age is interpreted here as a minimum constraint due to a proposed Pb-loss event that has likely influenced a number of published results. A comparison with the Geomagnetic Polarity Time Scale as well as published U-Pb TIMS ages from the overlying Beaufort Group supports a ca. 290-265 Ma age for deposition of the Ecca Group.

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High-precision timeline for Earth’s most severe extinction

Cited by 582 publications

References 60 publications

High-resolution biochronology and diversity dynamics of the Early Triassic ammonoid recovery: The Dienerian faunas of the Northern Indian Margin

High-resolution biochronology and diversity dynamics of the Early Triassic ammonoid recovery: The Dienerian faunas of the Northern Indian Margin

Deep crustal anatexis, magma mixing, and the generation of epizonal plutons in the Southern Rocky Mountains, Colorado

Refining the chronostratigraphy of the Karoo Basin, South Africa: magnetostratigraphic constraints support an early Permian age for the Ecca Group

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