However, there may be some weak links in this chain of events: the changes in the 13C/12C ratio expected to result from a massive release of methane do not match the patterns seen throughout the early Triassic; and the types of oceanic thermohaline circulation that may have existed at the end of the Permian are not likely to have supported deep-sea anoxia.
Porén, podería haber algúns elos febles nesta cadea de feitos: os cambios na proporción 13C/12C esperados como resultado dunha liberación masiva de metano non se corresponden cos observados ao longo do Triásico; e os tipos de circulación termohalina oceánica que puideron existir ao final do Permiano non é probable que mantiveran a anoxia do mar profundo.