Abstract
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 Bellerophon 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. doi: 10.1002/mmng.200900007
Highlights
The most severe mass extinction of the Phanerozoic affected marine and continental biota in the latest Permian, close to the Permian–Triassic (P–T) boundary (e.g., Schindewolf 1953; Sepkoski 1989; Raup 1991; Erwin 2006; Kozur 1998a)
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 suggested by palaeomagnetic correlation
What triggered the P–T boundary d13C trend is still under discussion. Several possible causes, such as Siberian Trap volcanism (e.g., Renne et al 1995; Kozur 1998a, 1998b; Svensen et al 2004; Hansen 2006; Payne & Kump 2007; Retallack & Jahren 2008; Korte et al 2009), re-mobilisation of formerly deposited 13C-depleted organic material due to enhanced weathering triggered by sea-level fall (e.g., Holser & Magaritz 1992), dissociation of isotopically light methane clathrates (e.g., Erwin 1994; Krull & Retallack 2000; Krull et al 2000; Twitchett et al 2001; Wit et al 2002; Sarkar et al 2003), a collapse in primary oceanic productivity (e.g., Visscher et al 1996; Rampino & Caldeira 2005), and shallow marine anoxia resulting
Summary
The most severe mass extinction of the Phanerozoic affected marine and continental biota in the latest Permian, close to the Permian–Triassic (P–T) boundary (e.g., Schindewolf 1953; Sepkoski 1989; Raup 1991; Erwin 2006; Kozur 1998a) This event was accompanied by spectacular global environmental changes, involving significant perturbations of Earth’s carbon cycle expressed as a prominent negative carbon-isotope excursion (e.g., Chen et al 1984; Holser & Magaritz 1987; Magaritz et al 1988; Holser et al 1989; Oberhånsli et al 1989; Wang et al 1994; Morante 1996; Wignall et al 1998; Heydari et al 2000; Krull & Retallack 2000; Krull et al 2000; Twitchett et al 2001; Musashi et al 2001; Wit et al 2002; Sephton et al 2002; Korte et al 2004a, 2004b, 2004c, 2005, 2009; Thomas et al 2004; Korte & Kozur 2005a, 2005b; Algeo et al.2007a, 2007b; Coney et al 2007; Riccardi et al 2007).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
