Hg Isotopes and Enhanced Hg Concentration in the Meishan and Guryul Ravine Successions: Proxies for Volcanism Across the Permian-Triassic Boundary

High-resolution organic carbon isotope (δ13C), Hg concentration and Hg isotopes curves are presented for the Permian-Triassic boundary (PTB) sections at Guryul Ravine (India) and Meishan D (China). The total organic carbon (TOC)-normalized Hg concentrations reveal more intense environmental changes at the Latest Permian Mass Extinction (LPME) and the earliest Triassic Mass Extinction (ETME) horizons coinciding with major δ13C shifts. To highlight palaeoredox conditions we used redox-sensitive elements and Rare Earth Element distribution. At Meishan, three Hg/TOC spikes (I, II, and III) are observed. Spike I remains after normalization by total aluminum (Al), but disappears when normalized by total sulfur (TS). Spike III, at the base of Bed 26, corresponds with excursions in the Hg/TS and Hg/Al curves, indicating a change in paleoredox conditions from anoxic/euxinic in the framboidal pyrite-bearing sediments (Bed 26) to oxygenated sediments (Bed 27). At Guryul Ravine, four Hg/TOC spikes were observed: a clear spike I in Bed 46, spike II at the base of the framboidal pyrite-rich Bed 49, spike III at the PTB, and spike IV at the LPME horizon. Some of these Hg/TOC spikes disappear when TS or Al normalization is applied. The spike I remains in the Hg/TS and Hg/Al curves (oxic conditions), spike II only in the Hg/TS curve (anoxic/euxinic), and spikes III and IV only in Hg/Al curves (oxic). In both sections, Hg deposition was organic-matter bound, the role of sulfides being minor and locally restricted to framboidal pyrite-bearing horizons. Positive mass-independent fractionation (MIF) for Hg odd isotopes (odd-MIF) was observed in pre-LPME samples, negative values in the LPME–PTB interval, and positive values above the ETME horizon. Most Hg-isotope patterns are probably controlled by the bathymetry of atmospheric Hg-bearing deposits. The source of Hg can be attributed to the Siberian Traps Large Igneous Province (STLIP). In the LPME-PTB interval, a complex of STLIP sills (Stage 2) intruded coal-bearing sediments. The negative δ202Hg, the mercury odd-MIF Δ201Hg patterns, and the Δ199Hg–Hg plot in both sections are compatible with volcanic mercury deposition. Our study shows the strength of Hg/TOC ratios as paleoenvironmental proxy and as a tool for stratigraphic correlation.

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Archosauriform footprints in the Lower Triassic of Western Alps and their role in understanding the effects of the Permian-Triassic hyperthermal

PeerJ ◽

10.7717/peerj.10522 ◽

2020 ◽

Vol 8 ◽

pp. e10522

Author(s):

Fabio Massimo Petti ◽

Heinz Furrer ◽

Enrico Collo ◽

Edoardo Martinetto ◽

Massimo Bernardi ◽

...

Keyword(s):

Mass Extinction ◽

Lower Triassic ◽

Western Alps ◽

Large Igneous Province ◽

Early Triassic ◽

Triassic Boundary ◽

Habitable Zones ◽

Single Well ◽

Permian Mass Extinction ◽

Permian Triassic Boundary

The most accepted killing model for the Permian-Triassic mass extinction (PTME) postulates that massive volcanic eruption (i.e., the Siberian Traps Large Igneous Province) led to geologically rapid global warming, acid rain and ocean anoxia. On land, habitable zones were drastically reduced, due to the combined effects of heating, drought and acid rains. This hyperthermal had severe effects also on the paleobiogeography of several groups of organisms. Among those, the tetrapods, whose geographical distribution across the end-Permian mass extinction (EPME) was the subject of controversy in a number of recent papers. We here describe and interpret a new Early Triassic (?Olenekian) archosauriform track assemblage from the Gardetta Plateau (Briançonnais, Western Alps, Italy) which, at the Permian-Triassic boundary, was placed at about 11° North. The tracks, both arranged in trackways and documented by single, well-preserved imprints, are assigned to Isochirotherium gardettensis ichnosp. nov., and are here interpreted as produced by a non-archosaurian archosauriform (erytrosuchid?) trackmaker. This new discovery provides further evidence for the presence of archosauriformes at low latitudes during the Early Triassic epoch, supporting a model in which the PTME did not completely vacate low-latitude lands from tetrapods that therefore would have been able to cope with the extreme hot temperatures of Pangaea mainland.

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Triassic Foraminifera from the Great Bank of Guizhou, Nanpanjiang Basin, south China: taxonomic account, biostratigraphy, and implications for recovery from end-Permian mass extinction

Journal of Paleontology ◽

10.1017/jpa.2021.10 ◽

2021 ◽

pp. 1-53

Author(s):

Demir Altıner ◽

Jonathan L. Payne ◽

Daniel J. Lehrmann ◽

Sevinç Özkan-Altıner ◽

Brian M. Kelley ◽

...

Keyword(s):

South China ◽

Mass Extinction ◽

Environmental Changes ◽

Carbonate Platform ◽

Ecological Niches ◽

Ocean Bottom ◽

Triassic Boundary ◽

Permian Mass Extinction ◽

Benthic Ecosystems ◽

Permian Triassic Boundary

Abstract Foraminifera are important components of tropical marine benthic ecosystems and their recovery pattern from the end-Permian mass extinction can yield insights into the Mesozoic history of this group. Here we report the calcareous and agglutinated foraminifera recovered from five measured stratigraphic sections on the Great Bank of Guizhou, an uppermost Permian to Upper Triassic isolated carbonate platform in the Nanpanjiang Basin, south China. The material contains >100 Triassic species, including three that are newly described (Arenovidalina weii n. sp., Meandrospira? enosi n. sp., and Spinoendotebanella lehrmanni n. gen., n. sp.), ranging from Griesbachian (Induan) to Cordevolian (Carnian) age. The species belong to the classes Miliolata, Textulariata, Fusulinata, Nodosariata, and to an unknown class housing all aragonitic forms of the orders Involutinida and Robertinida. Based on previously established conodont zones and carbon isotope chemostratigraphy, the Griesbachian (early Induan) through Illyrian (late Anisian) interval has been subdivided into 12 foraminiferal zones and two unnamed intervals devoid of foraminifera. Following the extinction at the Permian-Triassic boundary, habitable ecological niches of Griesbachian age were invaded by disaster taxa that subsequently became extinct during the Dienerian (late Induan) and left no younger descendants. The disaster taxa were replaced by Lazarus taxa with Permian origins, which were then decimated by the Smithian-Spathian (mid-Olenekian) boundary crisis. The tempo of recovery appears to have been modulated by environmental changes during the Griesbachian through Smithian that involved both climate change and expansion of anoxic ocean bottom waters. Uninterrupted and lasting recovery of benthic foraminifera did not begin until the Spathian. UUID: http://zoobank.org/2a6e9061-b163-402a-9098-8765a80576b3

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MINERALOGY AND GEOCHEMISTRY OF THE PERMIAN – TRIASSIC BOUNDARY (PTB) STRATA IN THE ABADEH SECTION OF IRAN AND THEIR IMPLICATIONS FOR THE MASS EXTINCTION

10.1130/abs/2016am-286709 ◽

2016 ◽

Author(s):

Nasser Arzani ◽

◽

Ezat Heydari ◽

Jamshid Hassanzadeh

Keyword(s):

Mass Extinction ◽

Triassic Boundary ◽

Permian Triassic Boundary

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Aras Valley (northwest Iran): high-resolution stratigraphy of a continuous central Tethyan Permian–Triassic boundary section

Fossil Record ◽

10.5194/fr-23-33-2020 ◽

2020 ◽

Vol 23 (1) ◽

pp. 33-69 ◽

Cited By ~ 1

Author(s):

Jana Gliwa ◽

Abbas Ghaderi ◽

Lucyna Leda ◽

Martin Schobben ◽

Sara Tomás ◽

...

Keyword(s):

High Resolution ◽

Carbon Isotopes ◽

Environmental Changes ◽

Triassic Boundary ◽

Nw Iran ◽

Environmental Setting ◽

Before And After ◽

Permian Extinction ◽

Permian Mass Extinction ◽

Permian Triassic Boundary

Abstract. The Permian–Triassic boundary section in the Aras Valley in NW Iran is investigated with respect to carbonate microfacies, biostratigraphy (particularly conodonts, nautiloids, and ammonoids), chemostratigraphy (carbon isotopes), and environmental setting. Correlation of the data allows the establishment of a high-resolution stratigraphy based on conodonts (with four Wuchiapingian, 10 Changhsingian, and three Griesbachian zones), ammonoids (with nine Changhsingian zones), and carbon isotopes; it forms the base for the reconstruction of the environmental changes before and after the end-Permian extinction event at the studied locality. In the Aras Valley section, there is no evidence for the development of anoxic conditions, associated with the end-Permian mass extinction.

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Siberian Trap volcanism, global warming and the Permian-Triassic mass extinction: New insights from Armenian Permian-Triassic sections: Comment

Geological Society of America Bulletin ◽

10.1130/b36099.1 ◽

2021 ◽

Author(s):

Micha Horacek ◽

Leopold Krystyn ◽

Aymon Baud

Keyword(s):

Global Warming ◽

Mass Extinction ◽

Seawater Temperature ◽

Correct Position ◽

Triassic Boundary ◽

Temperature Changes ◽

Siberian Trap ◽

Stratotype Section ◽

Permian Triassic Boundary

Joachimski et al. carried out geochemical investigations to study seawater temperature changes and their potential triggers across the Permian-Triassic Boundary (PTB). Unfortunately, in our opinion, an incorrect biochronology was applied to define the PTB, and the existing alternative was not considered, nor the reasoning explained. As a consequence, Joachimski et al. report diachronous temperature changes for the investigated Chanakhchi section with respect to the global stratotype section and point (GSSP) in Meishan, China. This discrepancy disappears when the, in our view, correct position of the PTB is adopted by using the proper biochronology.

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Precession-driven monsoon variability at the Permian–Triassic boundary — Implications for anoxia and the mass extinction

Global and Planetary Change ◽

10.1016/j.gloplacha.2012.06.006 ◽

2013 ◽

Vol 105 ◽

pp. 160-170 ◽

Cited By ~ 23

Author(s):

Arne Winguth ◽

Cornelia Winguth

Keyword(s):

Mass Extinction ◽

Triassic Boundary ◽

Monsoon Variability ◽

Permian Triassic Boundary

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What caused Earth's largest mass extinction event? New evidence from the Permian-Triassic boundary in northeastern Utah

Global and Planetary Change ◽

10.1016/j.gloplacha.2019.03.013 ◽

2019 ◽

Vol 177 ◽

pp. 81-100 ◽

Cited By ~ 5

Author(s):

Benjamin J. Burger ◽

Margarita Vargas Estrada ◽

Mae Sexauer Gustin

Keyword(s):

Mass Extinction ◽

Triassic Boundary ◽

Extinction Event ◽

Mass Extinction Event ◽

Permian Triassic Boundary ◽

New Evidence

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Rebound from the Permian/Triassic mass extinction: evolutionary paleoecology of sequential early Triassic (Smithian to Spathian) marine paleocommunities

The Paleontological Society Special Publications ◽

10.1017/s2475262200008212 ◽

1992 ◽

Vol 6 ◽

pp. 261-261

Author(s):

Jennifer K. Schubert ◽

David J. Bottjer

Keyword(s):

Mass Extinction ◽

Lower Triassic ◽

Upper Permian ◽

Early Triassic ◽

Triassic Boundary ◽

Biotic Recovery ◽

The Status ◽

Life Habits ◽

Stalked Crinoids ◽

Permian Triassic Boundary

The Permian/Triassic mass extinction, the most devastating biotic crisis of the Phanerozoic, has aroused considerable scientific interest. However, because research has focused primarily on understanding the magnitude of diversity reduction and causal mechanisms, the nature and timing of biotic recovery in the Early Triassic are still poorly understood. Marine limestones in the Lower Triassic Moenkopi Formation, which disconformably overlies the Upper Permian of southeastern Nevada and southern Utah, provide a rare opportunity to study the aftermath of the mass extinction in shallow water carbonate environments.Two contemporaneous members of the Moenkopi record the first marine incursion from the northwest in the Early Triassic (Smithian), the very sparsely fossiliferous marginal marine Schnabkaib Member in Nevada and southwest Utah, and the Sinbad Limestone in central-southern Utah, a marine unit dominated by amalgamated and condensed fossil-rich beds. The Virgin Limestone member was deposited during a subsequent (Spathian) Early Triassic sea level rise, about 4-5 Ma following the Permian/Triassic boundary, and includes nearshore and inner shelf limestones characterized by fossiliferous storm beds.Because the fossiliferous limestones of the Smithian Sinbad and the Spathian Virgin were deposited in similar shallow subtidal settings, they provide an opportunity to compare and contrast the status of biotic rebound at different points along an Early Triassic “time transect.” Analysis of bulk samples reveals that the older Sinbad and younger Virgin are similar in each possessing 2-3 different benthic marine paleocommunities of low within-habitat species richness. There are, however, several important differences between the Sinbad and Virgin faunas. The richly fossiliferous Sinbad assemblages are primarily molluscan, composed of approximately 2-8 species of bivalves, which may or may not be accompanied by ammonoids and 0-11 species of gastropods. Small spines, possibly belonging to an echinoid, are numerous in some samples. Although bivalves are also abundant in Virgin Limestone assemblages, fossils of other higher taxa are well-represented, including abundant crinoid ossicles, common brachiopods, echinoid spines and plates, and rare ammonoids and gastropods. Sinbad faunas also appear to lack epibionts and borers, while they are present but not abundant in the Virgin.The addition from Sinbad to Virgin times of groups other than molluscs, with different life habits and strategies, most likely led to an increase in spatial partitioning and resource utilization, in particular the development of epifaunal tiering with the appearance of stalked crinoids in the Virgin. This pattern of earliest Triassic community dominance by molluscs followed by later more “Paleozoic-like” communities has been observed in other regions. Earliest Triassic paucity of epibionts and borers indicates significant reduction in the biotic component of taphonomic processes, including taphonomic feedback, when compared with other time intervals. Data from these Early Triassic assemblages thus indicate the initiation of both an evolutionary and an ecological rebound between Sinbad (Smithian) and Virgin (Spathian) times.

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