A new scenario for the Domerian-Toarcian transition
Details
Serval ID
serval:BIB_367E64EBFBE3
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
A new scenario for the Domerian-Toarcian transition
Journal
Bulletin de la Société Géologique de France
ISSN-L
0037-9409
Publication state
Published
Issued date
2003
Peer-reviewed
Oui
Volume
174
Pages
351-356
Language
english
Abstract
In contrast to the majority of recently published hypotheses, we believe that the main trigger for early Toarcian anoxia is neither increased primary productivity during the Tenuicostatum and Falciferum Zones nor sudden methane hydrate degassing close to the transition between these two zones. In our opinion, this peculiar paleoceanographic episode is linked to a major, though short-lived, regression at the end of Upper Domerian. Sea-level fall resulted from sudden cooling due to increased volcanic activity. This generated global thermal insulation and subsequent glaciation. The regression is responsible for a major hiatus over NW-European epicontinental seas and is later followed by the well-known Lower Toarcian transgression. The interval corresponding to this hiatus allowed vegetation to colonise vast newly emerged surfaces. The leaching and drowning of the accumulated organo-humic matter then triggered the anoxic cycle at the transgressive maximum, concomitant with a global warming.
Create date
19/11/2007 11:11
Last modification date
20/08/2019 14:24