Palaeoenvironments and palaeoceanography changes across the Jurassic/Cretaceous boundary in the Arctic realm: case study of the Nordvik section (north Siberia, Russia)

0428331 - GLÚ 2015 RIV SE eng J - Journal Article
Zakharov, V. A. - Rogov, M. A. - Dzyuba, O. S. - Žák, Karel - Košťák, M. - Pruner, Petr - Skupien, P. - Chadima, Martin - Mazuch, M. - Nikitenko, B. L.
Palaeoenvironments and palaeoceanography changes across the Jurassic/Cretaceous boundary in the Arctic realm: case study of the Nordvik section (north Siberia, Russia).
Polar Research. Roč. 33, 25 March (2014). ISSN 0800-0395. E-ISSN 1751-8369
R&D Projects: GA ČR GA205/07/1365
Institutional research plan: CEZ:AV0Z30130516
Institutional support: RVO:67985831
Keywords : biodiversity * stable isotopes * J/K boundary * Arctic Realm * palaeoceanography
Subject RIV: DB - Geology ; Mineralogy
Impact factor: 1.141, year: 2014

The Jurassic/Cretaceous transition was accompanied by significant changes in palaeoceanography and palaeoenvironments in the Tethyan Realm, but outside the Tethys such data are very scarce. Here we present results of a study of the most complete section in the Panboreal Superrealm, the Nordvik section. Belemnite δ18O data show an irregular decrease from values reaching up to +1.6> in the Middle Oxfordian and from +0.8 to −1.7> in the basal Ryazanian, indicating a prolonged warming. The biodiversity changes were strongly related to sea-level oscillations, showing a relatively low belemnite and high ammonite diversity during sea-level rise, accompanied by a decrease of the macrobenthos taxonomical richness. The most prominent sea-level rise is marked by the occurrence of open sea ammonites with Pacific affinities. Peak abundances of spores and prasinophytes correlate with a negative excursion in organic carbon δ13C near the J/K boundary and could reflect blooms of green algae caused by disturbance of the marine ecosystem.
Permanent Link: http://hdl.handle.net/11104/0233682