Stratigraphic significance of carbon isotope variations in the shallow-marine Seis/Siusi Permian–Triassic boundary section (Southern Alps, Italy)

Abstract

Carbonate carbon-isotope values from the Permian–Triassic (P–T) boundary section at Seis/Siusi (Southern Alps, Italy) show a trend similar to that in numerous other P–T boundary sections worldwide. Values decrease from 3.2‰ (V-PDB) in the upper <i>Bellerophon</i> Limestone Formation (Late Permian) to a minimum of –1.7‰ in the lower Mazzin Member. This minimum may represent the P–T boundary. The overall declining carbon-isotope trend is interrupted by a ca. 1‰ positive excursion in the higher Tesero Oolite Horizon. This positive peak is located at a higher lithostratigraphic level than a comparable peak in the adjacent Pufels section, which suggests that the Tesero Oolite Horizon in the Seis section is stratigraphically slightly older than in the Pufels section, and this is also suggested by palaeomagnetic correlation. It is therefore concluded that the base of the Tesero Oolite Horizon does not reflect a synchronous "current event" but is slightly diachronous, a result that was previously shown by biostratigraphic correlation. Nevertheless, this suggestion should be verified by further detailed litho-, magneto- and chemostratigraphic analysis of other P–T sections in the Southern Alps. <br><br> doi:<a href="http://dx.doi.org/10.1002/mmng.200900007" target="_blank">10.1002/mmng.200900007</a>

Organic carbon isotope values from the Late Permian Seis/Siusi succession (Dolomites, Italy): Implications for palaeoenvironmental changes

“…The carbonate carbon isotope trend in the Seis section is similar to those of other Southern Alps sections (e.g., Magaritz et al 1988;Holser et al 1989;Oberhån-sli et al 1989;Horacek et al 2007Horacek et al , 2010Kraus et al 2009; and to the general carbon isotope trend across the PTB as suggested by . We therefore propose that deviations of the d 13 C org record need extra explanation(s).…”

Massive volcanism at the Permian–Triassic boundary and its impact on the isotopic composition of the ocean and atmosphere

“…3) and Pufels ( Fig. 5; not expressed by Gorjan et al, 2008, d 13 C carb ), and is reported also in other sections, such as the Meishan B (China; Nan and Liu, 2004; not expressed in other datasets), Shahreza (Iran; Korte et al, 2004b), Zal (Iran; Korte et al, 2004c), Gartnerkofel core (Austria; Holser et al, 1989), Tesero (Italy; and Seis (Italy; Newton et al, 2004;Kraus et al, 2009), suggesting that it is a general feature. It can be therefore ruled out that a sudden breakdown of biological productivity, due to mass extinction (e.g.…”

Carbon-isotope stratigraphy across the Permian–Triassic boundary: A review

“…The lower Tesero Oolite Horizon of the Tesero and other sections in the Dolomites changes in the eastern part of the Southern Alps into the uppermost, somewhat shallowerwater Bellerophon Limestone, whereas the upper Tesero Oolite Horizon changes into the Mazzin Member. Therefore, in the eastern part of Southern Alps, the Mazzin Member lies directly on the Bellerophon Limestone, and the boundary between the two lithostratigraphic units corresponds there to the EH (Kozur, 1994(Kozur, , 1998aKraus et al, 2009). (N) Idrijca (Slovenia) modified after Dolenec et al (2001).…”