Publication Date:
2015-02-06
Description:
Mesozoic Oceanic Anoxic Events (OAEs) are an expression of major physical oceanographic changes at times of perturbation of the global carbon cycle. A northern Tethyan record of OAE2 is preserved in expanded Cenomanian–Turonian pelagic limestone sections (Seewen Formation) in eastern Switzerland. The new carbonate carbon-isotope stratigraphy extracted from these limestones demonstrates that the OAE2 is condensed in all the studied successions and only the onset of the δ 13 C excursion (5.0‰) is present. The condensed interval is characterized by dissolution features, which are filled by a glauconite quartz sandstone. This bed is overlain by a well-sorted sandstone with intercalated limestone pebbles (Götzis Member), which can be compared with palimpsest sands forming today along current-swept shelves. The wide distribution of this thin sandstone layer within OAE2 indicates that an intense, erosive, east-west trending shelf current was active during the highest sea-level and most extreme carbon-cycle perturbation of the OAE2. This article is protected by copyright. All rights reserved.
Print ISSN:
0954-4879
Electronic ISSN:
1365-3121
Topics:
Geosciences
