Pliensbachian–Toarcian (Early Jurassic) extinction in western North America ...

• Main Author: Caruthers, Andrew Harry
• Format: Text
• Language: English
• Published: University of British Columbia 2013
• Subjects: Arctic; Global warming; Methane hydrate
• Online Access: https://dx.doi.org/10.14288/1.0073839; https://doi.library.ubc.ca/10.14288/1.0073839

The Pliensbachian–Toarcian marine extinction is observable at the species and generic levels. Ammonite diversity data from Europe and parts of the Arctic suggest a multi-phased event with diversity declining over six separate intervals. The main-phase of decline begins at the Pliensbachian–Toarcian boundary and extends into the Early Toarcian to a level correlative with the Tenuicostatum / Serpentinum Zone boundary. To date only this main-phase has been demonstrated as being global in extent, affecting multiple taxonomic groups. The entire Pliensbachian-Toarcian extinction has been attributed to regional and global controlling mechanisms associated with the Volcanic Greenhouse Scenario, an hypothesis linking eruption of the Karoo–Ferrar large igneous province (LIP) to global warming and mass extinction, specifically involving the release of methane hydrate from shelf reservoirs and a global marine anoxic event in the Early Toarcian (the T–OAE). The study presented herein uses paleontology and isotope ...