A new Rhaetian δ13Corg record: Carbon cycle disturbances, volcanism, End-Triassic mass Extinction (ETE)

Intensified continental chemical weathering and carbon-cycle perturbations linked to volcanism during the Triassic–Jurassic transition

“…Carbon-isotope (inorganic and organic) and mercury records in sedimentary successions have been widely used to infer volcanism during the T–J transition. The CAMP coincided with ~3–6‰ negative CIEs in both carbonates and organic matter, which have been used to constrain its onset and duration 4 , 6 , 9 , 39 , 40 . The sources of isotopically light carbon are inferred to have been volcanic gases and/or thermogenic gases generated through magmatic intrusions into organic-rich strata 4 or dissociation of seafloor methane clathrates 7 .…”

“…Atmospheric CO 2 concentrations during the T–J transition increased by a factor of 2–4× relative to pre-T–J boundary values (i.e., from 1000–2000 ppm to 2000–4000 ppm 11 , 41 , 42 ). The presence of negative CIEs in carbonate and organic carbon isotope profiles of both marine and terrestrial T–J boundary sections serves to demonstrate the global extent of the underlying carbon-cycle perturbations 4 , 6 – 9 , 39 , 40 . Furthermore, these emissions of carbon-based greenhouse gases had deleterious bio-environmental effects: (1) higher temperatures—various marine and terrestrial proxies suggest an average global temperature rise of 3–4 °C 10 , 11 , 41 , (2) increased wildfire frequency in terrestrial habitats, attributed to climatic warming 43 – 45 , and (3) oceanic acidification due to higher carbon dioxide concentrations in seawater 13 , 14 .…”

New magnetobiostratigraphic results from the Ladinian of the Dolomites and implications for the Triassic geomagnetic polarity timescale

“…Marzoli et al, 2004;Hesselbo et al, 2007;Deenen et al, 2010;Dal Corso et al, 2014;Davies et al, 2017) and associated with the end-Triassic extinction event (e.g. Hesselbo et al, 2002;Guex et al, 2004;Ward et al, 2004;Richoz et al, 2007;Van de Schootbrugge et al, 2008;Tanner, 2010;Whiteside and Ward, 2011;Hillebrandt et al, 2013;Zaffani et al, 2017;Lucas and Tanner, 2018), are located in the murky SA5n.2n-SA6n magnetostratigraphic interval of the St. Audrie's Bay section (Hesselbo et al, 2002(Hesselbo et al, , 2004Hounslow et al, 2004) and in the BIT2r-BIT5n interval of Brumano/Italcementi Quarry (Muttoni et al, 2010;Zaffani et al, 2018), which broadly correspond to the E22n-E24n interval in the Newark-APTS (Fig. 13).…”

“…in Petrified Forest, and in Blackburn et al (2013) from Palisades Sill. Carbon Isotopes Excursions (CIE) in Brumano and Italcementi Quarry sections are from Zaffani et al (2018); CIEs in St. Audrie's Bay section are from Hesselbo et al (2002Hesselbo et al ( , 2004. Base of Daxatina canadensis ammonoid Subzone is from Prati di Stuores, Italy (Ladinian base;Broglio Loriga et al, 1999;Mietto et al, 2012), FOs of conodonts Metapolygnathus parvus and Carnepigondolella gulloae are from Pizzo Mondello, Italy (Norian base; Mazza et al, 2012a), FO of conodont Misikella posthernsteini s.s. is from Pignola-Abriola, Italy (Rhaetian base; Maron et al, 2015;Rigo et al, 2016;Bertinelli et al, 2016;Zaffani et al, 2017), FO of Psiloceras spelae is from Levanto, Peru (Hettangian base; Schoene et al, 2010;Guex et al, 2012;Wotzlaw et al, 2014).…”

Sedimentary record of Upper Triassic impact in the Lagonegro Basin, southern Italy: Insights from highly siderophile elements and Re-Os isotope stratigraphy across the Norian/Rhaetian boundary

“…Stepwise or episodic extinctions took place across the NRB, during which high extinction rates of ammonoids and marine bivalves, including pectinacean Monotis, have been documented (McRoberts, 2007(McRoberts, , 2010Wignall et al, 2007;Lucas and Tanner, 2008;Whiteside and Ward, 2011;Lucas, 2018aLucas, , 2018bRigo et al, 2020;Ogg et al, 2020), as well as significant faunal turnovers in radiolarians and conodonts occurred (O'Dogherty et al, 2010;Onoue et al, 2016;Du et al, 2020;Karádi et al, 2020). Most of these extinctions were long conflated as a single mass extinction at the end of the Triassic (Sepkoski Jr., 1982, 1996, but recent magneto-bio-stratigraphic (Gallet et al, 2007;Muttoni et al, 2010;Hüsing et al, 2011;Maron et al, 2015Maron et al, , 2019Kent et al, 2017) and carbon isotope stratigraphic studies (Sephton et al, 2002;Ward et al, 2004;Zaffani et al, 2017Zaffani et al, , 2018Rigo et al, 2020;Rigo and Campbell, 2021), and radiometric dating (Wotzlaw et al, 2014) have clearly distinguished them from the ETE.…”