Publication Date:
2012-05-01
Description:
Huang et al. (2011) have produced a valuable astro-chronological framework across the Permian-Triassic boundary in China and Austria. However, in doing so they define a mass extinction interval (MEI) and prolonged extinction lasting in all cases ∼700 k.y. The MEI in their study ranges from the start of the Neogondolella meishanensis conodont zone to the base of the Isarcicella isarcica zone, spanning four conodont zones. This is much too long a time period to assign to the extinction event. For the Meishan, China, section, most workers put the abrupt mass extinction horizon at the base of Bed 25 (Jin et al., 2000). More recently, Kaiho et al. (2009) narrowed the Late Permian mass extinction horizon to within a 1.2-cm-thick interval near the top of Bed 24e-2 in the condensed section at Meishan. A possible second abrupt extinction event takes place at the base of Bed 28 (Song et al., 2009). By contrast, Huang et al. define a prolonged MEI stretching from the top of Bed 24e to the base of Bed 29.
Print ISSN:
0091-7613
Electronic ISSN:
1943-2682
Topics:
Geosciences
