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2 (a) Exeter section composite from the Newark Basin including new data (red, Constitution Avenue) and previously published outcrop data from the Exeter area as well data from the Martinsville no. 1 core (Appendix Note 7), and outcrops at Woodland Park, N.J. (Appendix Note 8), projected in with scaling shown in Olsen et al. (2016b, Fig. 34). C = Clathropteris leaf fragments; S. o. = spinocaudatan Shipingia olseni. Notes: a from Olsen et al., 2002; b occurrence of Shipingia olseni in Martinsville no. 1 core anchored by being in the upper part of E23r of Kent et al. (1995) in that core; c occurrences of track taxon Eubrontes giganteus from exposures at Woodland Park; d fern spore percentages from Olsen et al. (2002) and Olsen et al. (2016b); e Rochechouart data from Tagle et al. (2009), normalized to C1 chondrite; f Canyon Diablo data from Tagle et al. (2009), normalized to C1 chondrite;

2 (a) Exeter section composite from the Newark Basin including new data (red, Constitution Avenue) and previously published outcrop data from the Exeter area as well data from the Martinsville no. 1 core (Appendix Note 7), and outcrops at Woodland Park, N.J. (Appendix Note 8), projected in with scaling shown in Olsen et al. (2016b, Fig. 34). C = Clathropteris leaf fragments; S. o. = spinocaudatan Shipingia olseni. Notes: a from Olsen et al., 2002; b occurrence of Shipingia olseni in Martinsville no. 1 core anchored by being in the upper part of E23r of Kent et al. (1995) in that core; c occurrences of track taxon Eubrontes giganteus from exposures at Woodland Park; d fern spore percentages from Olsen et al. (2002) and Olsen et al. (2016b); e Rochechouart data from Tagle et al. (2009), normalized to C1 chondrite; f Canyon Diablo data from Tagle et al. (2009), normalized to C1 chondrite;

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Multiple lines of evidence suggest that volcanic and thermogenic gas emanations from the voluminous eruptions of the Central Atlantic Magmatic Province (CAMP) triggered the end‐Triassic mass extinction. However, a comparison of the timing and duration of the biotic and environmental crises with the timing and duration of the magmatic activity is di...

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... It was emplaced at ca. 201 Ma, close to the Triassic-Jurassic boundary, during the early stages of the breakup of the supercontinent of Pangaea that led to the opening of the Central Atlantic Ocean [1][2][3][4][5]. CAMP magmatism is nowadays represented by remnants of intrusive (crustal underplates, layered intrusions, sills, dykes) and extrusive (pyroclastic sequences and lava flows) rocks that occur in once-contiguous parts of North and South America, northwestern Africa, and southwestern Europe, e.g., [4,[6][7][8][9][10][11][12]. It may have covered over 7 × 10 6 km 2 , with a total volume of magma estimated at 2-4 × 10 6 km 3 , [6,23,28]). ...
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The morphology, internal architecture, and emplacement mechanisms of the Central Atlantic Magmatic Province (CAMP) lava flows of the Hartford and Deerfield basins (USA) are presented. The Talcott, Holyoke, and Hampden formations within the Hartford basin constitute distinct basaltic units, each exhibiting chemical, mineralogical, and structural differences corresponding to flow fields. Each flow field was the result of several sustained eruptions that produced both inflated pahoehoe flows and subaquatic extrusions: 1–5 eruptions in the Talcott formation and 1–2 in Holyoke and Hampden basalts, where simple flows are dominant. The Deerfield basin displays the Deerfield basalt unit, characterized by pillow lavas and sheet lobes, aligning chemically and mineralogically with the Holyoke basalt unit. Overall, the studied flow fields are composed of thick, simple pahoehoe flows that display the entire range of pahoehoe morphology, including inflated lobes. The three-partite structure of sheet lobes, vertical distribution of vesicles, and segregation structures are typical. The characteristics of the volcanic pile suggest slow emplacement during sustained eruptive episodes and are compatible with a continental basaltic succession facies model. The studied CAMP basalts of the eastern United States are correlated with the well-exposed examples on both sides of the Atlantic Ocean (Canada, Portugal, and Morocco).
... The Central Atlantic Magmatic Province (CAMP) is one of the largest Large Igneous Province on Earth that was emplaced at ca. 201 Ma, close to the Triassic-Jurassic boundary, during the early 2 stages of the breakup of the supercontinent of Pangaea ( Figure 1) that led to the opening of the Central Atlantic Ocean [1][2][3][4][5]. CAMP magmatism is nowadays represented by remnants of intrusive (crustal underplates, layered intrusions, sills, dykes) and extrusive (pyroclastic sequences and lava flows) rocks that occur in once-contiguous parts of North and South America, northwestern Africa, and southwestern Europe e.g., [4,[6][7][8][9][10][11][12]. It may have covered over 7 x 10 6 km 2 , with a total volume of magma estimated at 2-4×10 6 km 3 , and it was active for no more than 4-5 Ma. ...
... However, the pillow breccias and pillow lavas of units 3 and 4 indicate that the basin was again inundated. 12 The Holyoke basalt, the second volcanic formation, corresponds to one thick sheet lobe of a simple inflated pahoehoe flow. The Holyoke basalt has erupted under subaerial conditions after the deposition of the underlying 100-250 m thick sediments (of the Shuttle Meadow Formation [36]). ...
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... Large volcanic and extraterrestrial impact events in the Late Triassic have been detected from protracted negative osmium (Os) isotopic shifts and high abundances of highly siderophile elements (HSEs: Os, Ir, Ru, Pt, Rh, Pd, and Re) in sedimentary rocks (Cohen and Coe, 2002;Ravizza and Peucker-Ehrenbrink, 2003;Tanner and Kyte, 2005;Kuroda et al., 2010;Onoue et al., 2012;Sato et al., 2013Sato et al., , 2016Sato et al., , 2021Tegner et al., 2020;Tomimatsu et al., 2021;Whiteside et al., 2021;de Graaff et al., 2022). Seawater Os isotope ratios ( 187 Os/ 188 Os) recorded by marine sediments reflect changes in the relative inputs of unradiogenic Os from the mantle and extraterrestrial materials ( 187 Os/ 188 Os ~0.12) and radiogenic Os from continental materials ( 187 Os/ 188 Os ~1.4) (Peucker-Ehrenbrink and . ...
... In addition, possible ejecta deposits derived from the Rochechouart structure (206.92 ± 0.32 Ma; Cohen et al., 2017) in France have been reported from uppermost Sevatian 2 (Misikella hernsteini conodont zone) deposits of the Western Tethys . Although the decrease in 187 Os/ 188 Os i values identified in this study is unlikely to record the Rochechouart impact event due to its age, we examined the HSE abundances to distinguish between an extraterrestrial signature (e.g., Alvarez et al., 1980;Onoue et al., 2012;Sato et al., 2016;Goderis et al., 2021) and volcanic activity (e.g., Tanner and Kyte, 2005;Tegner et al., 2020;Whiteside et al., 2021). ...
... In addition, in the paleotropical latest Rhaetian and Early Jurassic, Clathropteris leaves are restricted to beds very close in time to major lava flows, suggesting a possible association with major volcanic winter episodes Whiteside et al. 2022). The palynological ETE in eastern North America, is in fact directly associated with a fern spike, the spores comprising that abundance peak are Granulatisporites infirmis, produced by Clathropteris menicoides (Cornet and Traverse 1975;Whiteside et al. 2020). The geographic distribution of Clathropteris, especially in Siberia indicates it did tolerate the prolonged arctic darkness, and suggests it could probably tolerate freezing temperatures, but it may also have been a generalist adapted to highly disturbed conditions. ...
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... In addition, reliable correlation of the specific magmatic activities of the CAMP with the biotic events is difficult to establish with the existing data (Whiteside et al. 2021). Some authors assert time equivalence between the ETE and CAMP eruptive pulses (Deenen et al. 2010;Schoene et al. 2010;Whiteside et al. 2010Whiteside et al. , 2021Blackburn et al. 2013;Dal Corso et al. 2014). ...
... In addition, reliable correlation of the specific magmatic activities of the CAMP with the biotic events is difficult to establish with the existing data (Whiteside et al. 2021). Some authors assert time equivalence between the ETE and CAMP eruptive pulses (Deenen et al. 2010;Schoene et al. 2010;Whiteside et al. 2010Whiteside et al. , 2021Blackburn et al. 2013;Dal Corso et al. 2014). However, some previously published δ 13 C data show that the initiation of the negative CIE marking the extinction horizon predates the earliest lava flows, questioning the causal relationship between the eruptions of the CAMP and the ETE (Davies et al. 2017;Yager et al. 2017). ...
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Large magnitude and rapid negative carbon isotope (δ ¹³ C) excursions (CIEs) in the Triassic-Jurassic boundary (TJB) interval have been proposed as critical evidence for the hypothesis that the emplacement of Central Atlantic Magmatic Province (CAMP) has triggered global carbon cycle perturbations and the end-Triassic mass extinction (ETE). However, the pattern and timing of δ ¹³ C variations during the ETE remain poorly constrained. Here I present high-resolution organic carbon isotope (δ ¹³ C org ) records from a terrestrial TJB succession continuously exposed along the Haojiagou valley in southern margin of the Junggar Basin, northwestern China. The δ ¹³ C chemostratigraphic correlations, combined with the palynological data, indicate that the position of the TJB should be placed at the base of bed 53. Importantly, the results show that two rapid negative CIEs at the end Triassic roughly coincided with two episodes of variations in the palynological records. This observation supports the hypothesis that two pulses of biotic crisis of the ETE may have been triggered by two major episodes of magmatic activities of CAMP. In addition, the data in this study support an early start of CAMP magmatic activities in early Rhaetian, which may have led to a global carbon cycle perturbation and the related biotic crisis or turnover.
... The event coincided with an acute carboncycle perturbation, as indicated by a large (up to 6‰) negative carbonisotope (δ 13 C) excursion (e.g., Pálfy et al., 2001;Ward et al., 2001;Hesselbo et al., 2002;Whiteside et al., 2010;Lindström et al., 2017Lindström et al., , 2021 in both marine and terrestrial sedimentary records, as well as stomatal index and pedogenic carbonate evidence for a rise in atmospheric CO 2 (McElwain et al., 1999;Schaller et al., 2011;Steinthorsdottir et al., 2011). Stratigraphic records of the extinction are also marked by mercury (Hg; Thibodeau et al., 2016;Percival et al., 2017;Lindström et al., 2019;Kovács et al., 2020;Yager et al., 2021) and highly siderophile element (HSE) enrichments (e.g., Ir, Ru, Rh, Pt, Pd; Olsen et al., 2002aOlsen et al., , 2002bWhiteside et al., 2021), as well as a shift towards a relatively unradiogenic 187 Os/ 188 Os i composition of seawater (Cohen and Coe, 2002;Kuroda et al., 2010). The ETE was contemporaneous with the early onset of volcanism associated with the Central Atlantic Magmatic Province (CAMP), based on radioisotopic dating of volcanic ash layers just above the extinction horizon, CAMP igneous units themselves, and the documentation of CAMP lavas interbedded with sedimentary records of the event (e.g., Schoene et al., 2010;Marzoli et al., 2011;Blackburn et al., 2013;Wotzlaw et al., 2014;Davies et al., 2017). ...
... Consequently, increased emissions of CO 2 and other gases such as SO 2 (Bacon et al., 2013;Steinthorsdottir et al., 2018) from CAMP volcanic outpouring and/or sill intrusions are widely implicated as the main trigger of the extinction (e.g., Wignall, 2001;Deenen et al., 2010;Davies et al., 2017;Heimdal et al., 2018). The Hg and platinum-group element (PGE: Ru, Rh, Pd, Os, Ir, Pt) enrichments and shifts towards more unradiogenic osmium-isotope seawater compositions have been explained as a further consequence of, and proxy for, this volcanism (e. g., Kuroda et al., 2010;Thibodeau et al., 2016;Percival et al., 2017;Lindström et al., 2019;Whiteside et al., 2021). Alternative hypotheses have been proposed, such as methane hydrate release as an alternative source of the carbon emissions (Beerling and Berner, 2002), and a meteorite impact event as a source of the HSE enrichment (Olsen et al., 2002a(Olsen et al., , 2002bde Graaff et al., 2017), which is similar, though an order of magnitude lower, to the well-documented HSE enrichment associated with the Cretaceous-Paleogene (K-Pg) boundary mass extinction (Alvarez et al., 1980;Smit and Hertogen, 1980;Goderis et al., 2013Goderis et al., , 2021. ...
... Alternative hypotheses have been proposed, such as methane hydrate release as an alternative source of the carbon emissions (Beerling and Berner, 2002), and a meteorite impact event as a source of the HSE enrichment (Olsen et al., 2002a(Olsen et al., , 2002bde Graaff et al., 2017), which is similar, though an order of magnitude lower, to the well-documented HSE enrichment associated with the Cretaceous-Paleogene (K-Pg) boundary mass extinction (Alvarez et al., 1980;Smit and Hertogen, 1980;Goderis et al., 2013Goderis et al., , 2021. However, the mounting evidence for CAMP volcanism over methane hydrate release from other sources (see e.g., Heimdal et al., 2018Heimdal et al., , 2019Lindström et al., 2019;Whiteside et al., 2021) and the lack of additional supportive evidence for an impact event such as impact spherules, Ni-rich spinel crystals, shocked quartz or an impact structure of a correct age (see e.g., Tanner et al., 2004Tanner et al., , 2008, leaves CAMP volcanism as the more widely accepted cause. ...
Article
The end-Triassic extinction event (~ 201.5 Ma) is one of the five major mass extinction events in Earth's history, however, considerable discussion continues on the exact causes and timing of the event. This is because, whilst certain geochemical data on T-J sections appears to be largely comparable globally, with for example a significant (up to 6‰) negative carbon-isotope (δ¹³C) excursion at the extinction horizon, more often than not other geochemical variations are neither uniform nor fully consistent between sections. Critical to this discussion is that the majority of the studied sections containing the end-Triassic extinction event are limited to shallow marine or terrestrial sections, which are prone to discontinuities and hiatuses. In this study, we present carbon isotopes (δ¹³Ccarb), total organic carbon (TOC), major and trace, mercury (Hg) and highly siderophile elements (HSE), osmium-isotope compositions and paleomagnetic data of a relatively less studied deep-marine T-J succession in the Budva Basin, Čanj, Montenegro. At Čanj, deep-marine Triassic limestones are abruptly interrupted by a ~ 6 cm finely laminated clay layer, before transitioning to more argillaceous Jurassic red beds. The clay layer is interpreted to represent the end-Triassic extinction interval and is characterized by a negative carbon isotope excursion, relative heavy rare earth element (HREE) enrichment, Hg increase, HSE enrichment and a sharp shift to unradiogenic osmium-isotopic ratios. This establishes the Čanj section as a unique and well-preserved outcrop that exquisitely encapsulates the end-Triassic extinction in the Tethyan marine realm. The distinct geochemical markers recorded at Čanj are consistent with the Central Atlantic Magmatic Province as the main driver behind the end-Triassic extinction.
... In numerous previous studies, high platinum-group element (PGE) concentrations and negative osmium (Os) isotope anomalies preserved in sedimentary rocks have been used to detect large impact and volcanic events in the Late Triassic (Cohen and Coe, 2002;Olsen et al., 2002;Tanner and Kyte, 2005;Kuroda et al., 2010;Onoue et al., 2012;Sato et al., 2013Sato et al., , 2016Clutson et al., 2018;Nozaki et al., 2019;Tomimatsu et al., 2021;Whiteside et al., 2021). Since the discovery of anomalous concentrations of iridium (Ir) and other PGE (Os, Pt, Pd, and Ru) at the Cretaceous/Paleogene (K/Pg) boundary by Alvarez et al. (1980) and Ganapathy (1980), PGE anomalies have been regarded as geochemical evidence for the impact event (e.g., Ebihara and Miura, 1996;Goderis et al., 2013;Sato et al., 2016). ...
... Given this small amount of contamination, it may be reasonable that our thin-section observations for SVSC5 cannot confirm unequivocal signs of impact such as microspherule and Ni-rich crystals (Fig. 5B), which are abundantly found in ejecta layers of Manicouagan (Onoue et al., 2012;Sato et al., 2013). The Late Triassic is marked not only two large impact craters of Manicouagan and Rochechouart but also large volcanic activities documented by LIP formations such as the Angayucham Province cropping out in the Alaska and the CAMP emplaced in the central portion of Pangea, both of which might be invoked as the potential causes of PGE enrichments in sedimentary successions (e.g., Tegner et al., 2020;Whiteside et al., 2021). However, based on the above arguments and several lines of evidence summarized below, we propose that the shaley bed with PGE anomaly in the study section is sourced by Rochechouart impact melt, probably transported as fine particulates from the continental Massif Central in France by high-energetic erosion related to impact-triggered tsunami, rather than atmospheric fallout of dust and melt droplets as with the case of PGE-enriched ejecta layers in K/Pg boundary and Manicouagan. ...
Article
The Norian and Rhaetian transition (Late Triassic) is characterized by a faunal turnover in major pelagic groups, such as radiolarians, conodonts, and ammonoids. Although catastrophic events such as emplacements of large igneous provinces and/or extraterrestrial impacts have been suggested to account for this biotic turnover, firm evidence based on geochemistry of sedimentary successions is still lacking. In order to assess environmental changes across the Norian/Rhaetian boundary (NRB), we report high–resolution stratigraphic variations for whole-rock major, trace, and highly siderophile element abundances, together with ReOs isotope ratios for the Sasso di Castalda section in Lagonegro Basin, southern Italy. The section consists of a continuously exposed sequence of upper Norian (Sevatian) through the lower Rhaetian of a deep basinal deposits. Our data demonstrated that the upper Norian section records important events in stratigraphically ascending order: (1) a depositional environment moved below the Carbonate Compensation Depth, leading to the carbonate-biosilica transition associated with a slight depletion of elements favored in heavy minerals such as Zr, Hf, and Ti, (2) an input of Rochechouart impact components detected by platinum-group element anomaly, and (3) a transient change of redox state into low oxygen (dysoxic to suboxic) conditions marked by increases of V, U, and Re. This sequence of events suggests that the Rochechouart impact predates the major environmental changes resulting in faunal turnover at the NRB. Although their direct causal relationships are highly questionable given the small size of impactor and the interval between the impact horizon and the NRB, the possibility of triggering subsequent environmental and biotic collapses cannot be ruled out. This study provides the first identification of Rochechouart impact horizon in marine strata, which could be an important event marker for further studies on contemporaneous sections in the Lagonegro Basin and other localities.
Article
Mesozoic continental basins of northern China, including the Junggar Basin, provide some of the most spectacular and important fossil assemblages in the world, but their climatic and environmental contexts have been shrouded in uncertainty. Here we examine the main factors that determine those contexts: palaeolatitude; the effects of changing atmospheric gases on the radiative balance; and orbitally paced variations in insolation. Empirical evidence on these factors is accumulating rapidly and promises to upend many long standing paradigms. We focus primarily on the Junggar Basin in Xinjiang northwest China with the renowned Shishugou Biota and the basins in Liaoning, Hebei, and Inner Mongolia with their famous Jehol and Yanliao Biotas. Accurate geochronology is necessary for disentangling these various factors and we review the Late Triassic to Early Cretaceous U-Pb ages for these areas and supply one new LA-ICP-MS age for the otherwise un-dated Sangonghe Formation of Early Jurassic age. We review climatic-sensitive facies patterns in North China and show that the climatic context changed synchronously in northwestern and northeastern China consistent with a previously proposed huge Late Jurassic-earliest Cretaceous True Polar Wander (TPW) event with all the major plates of East Asia docked with Siberia and moving together since at least the Triassic, when the north China Basins were at Arctic latitudes. We conclude that this TPW shift is was responsible for the coals and ice rafted debris being produced at high latitudes and the red beds and eolian strata being deposited at low latitudes, within the same basin. The climatic and taphonomic context in which the famous Shishugou, Yanlaio and Jehol biotas preserved was thus a function of TPW as opposed to local tectonics or climate change. Supplementary material at https://doi.org/10.6084/m9.figshare.c.6738045
Article
The Triassic–Jurassic transition, which is here broadly defined as extending from the Late Triassic through the Early Jurassic (~237 Ma to 174 Ma), was an important interval in Earth history. The end-Triassic mass extinction (ETME), at ~201 Ma, ranks among the ‘Big Five’ Phanerozoic mass extinctions. It largely completed the shift from the ‘Paleozoic Evolutionary Fauna’ to the ‘Modern Evolutionary Fauna’ that had been initiated by the end-Permian mass extinction, and may have contributed to the ‘Mesozoic Marine Revolution’ and rise of dinosaurs to dominance in terrestrial environments. In addition, the Triassic–Jurassic transition encompasses a second-order mass extinction during the early Toarcian oceanic anoxic event (T-OAE), at ~181 Ma. The ETME was triggered by Central Atlantic Magmatic Province (CAMP) magmatism, and the T-OAE by Karoo-Ferrar Large Igneous Province (KFLIP) magmatism, both associated with the stepwise disintegration of the Pangean supercontinent. These events led to major changes in continental and marine habitats, including climatic warming, ocean acidification, and widespread watermass anoxia, that produced a cascade of lethal environmental stresses. This article undertakes a review of the ETME and T-OAE mass extinctions, the large igneous province eruptions that triggered those biotic events, and the web of environmental changes that linked them together.