Synchronism of the Siberian Traps and the Permian-Triassic Boundary

Abstract

Uranium-lead ages from an ion probe were taken for zircons from the ore-bearing Noril'sk I intrusion that is comagmatic with, and intrusive to, the Siberian Traps. These values match, within an experimental error of +/-4 million years, the dates for zircons extracted from a tuff at the Permian-Triassic (P-Tr) boundary. The results are consistent with the hypothesis that the P-Tr extinction was caused by the Siberian basaltic flood volcanism. It is likely that the eruption of these magmas was accompanied by the injection of large amounts of sulfur dioxide into the upper atmosphere, which may have led to global cooling and to expansion of the polar ice cap. The P-Tr extinction event may have been caused by a combination of acid rain and global cooling as well as rapid and extreme changes in sea level resulting from expansion of the polar ice cap.

Triggers of Permo-Triassic boundary mass extinction in South China: The Siberian Traps or Paleo-Tethys ignimbrite flare-up?

“…Although no consensus has been reached so far on the causal mechanisms, the~250 Ma Siberian Traps is widely believed to be the ultimate cause of PTB mass extinction due to the coincidence of these two events (e.g., Campbell et al, 1992;Courtillot, 1994;Courtillot and Renne, 2003;Kamo et al, 2003Kamo et al, , 2006Racki and Wignall, 2005;Reichow et al, 2002;Renne et al, 1995). However, two potential pitfalls are associated with this methodology/reasoning: (a) If the two events took place at the same time, they are possibly but not necessarily related to each other.…”

Growth and demise of Permian biogenic chert along northwest Pangea: evidence for end-Permian collapse of thermohaline circulation

“…However, this trend sharply reverses near the Middle/Late Permian boundary at a time when chert deposition appears to have increased worldwide. Likewise, the end-Permian massive eruption of the Siberian traps (Campbell et al, 1992;Renne et al, 1995) coincides with the collapse, not the outburst, of chert factories around the world.…”

Paleomagnetic Constraints on the Permian-Triassic Boundary in Terrestrial Strata of the Karoo Supergroup, South Africa: Implications for Causes of the End-Permian Extinction Event

“…(Shishkin et al, 1986) has been reported form the lower Norilskian basalts of the Tungusska Basin, Siberia (A proposed candidate for the continental GSSP of the Permian-Triassic boundary (Lozovsky, 1998)). The Norilsky region intrusions are correlated to the Mokulaevskyi basalt (248±4 Ma; Campbell et al, 1992). If this occurrence of Lystrosaurus can be confirmed it would imply a Late Permian-Early Triassic age for the first occurrence of Lystrosaurus within these strata.…”