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

Polar research

Victor A. Zakharov¹  Mikhail A. Rogov²  Petr Skupien³  Martin Košt’ák⁴  Martin Mazuch⁴  Martin Chadima⁵  Petr Pruner⁵  Karel Žák⁵  Boris L. Nikitenko⁶  Oksana S. Dzyuba⁶ 

[1] Geological Institute of Russian Academy of SciencesPyzhevski lane, 7, Moscow RU-119017, Russia;Geological Institute of Russian Academy of SciencesPyzhevski lane, 7, Moscow RU-119017, RussiaCorrespondence;Institute of Geological EngineeringTechnical University of Ostrava, 17 listopadu 15, CZ-708 33, Ostrava-Poruba, Czech Republic;Institute of Geology and PalaeontologyFaculty of Science, Charles University in Prague, Albertov 6, CZ-128 43 Prague 2, Czech Republic;Institute of Geology of the Academy of Sciences of the Czech Republic, v.v.i., Rozvojová 269, CZ-165 00 Prague 6, Czech Republic;Trofimuk Institute of Petroleum Geology and GeophysicsSiberian Branch of Russian Academy of Sciences, Acad. Koptyug av., 3, Novosibirsk RU-630090,Russia

关键词: Biodiversity;    stable isotopes;    J/K boundary;    Arctic Realm;    palaeoceanography;   

DOI  :  10.3402/polar.v33.19714

学科分类：自然科学（综合）

来源: Co-Action Publishing

【 摘 要 】

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 ma...

【 授权许可】

CC BY-NC