Record details

    Palaeoenvironments and palaeoceanography changes across the Jurassic/Cretaceous boundary in the Arctic realm: case study of the Nordvik section (north Siberia, Russia)
    Chadima, Martin
    Dzyuba, O. S.
    Košťák, M.
    Mazuch, M.
    Nikitenko, B. L.
    Pruner, Petr
    Rogov, M. A.
    Skupien, P.
    Zakharov, V. A.
    Žák, Karel
Publication type
    článek v odborném periodiku
Source title - serial
    Polar Research
    Roč. 33, 25 March
    Projekt: GA205/07/1365, GA ČR3cav_un_auth*0228750
    Rozsah: 19 s. : E
    Výzkumný záměr: CEZ:AV0Z30130516
Subject category
    Arctic Realm
    J/K boundary
    stable isotopes
Abstract (in english)
   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.
    AV ČR Brno, Geologický ústav
Contributor code
    AV ČR, GLÚ
Source format
Import date
    23. 10. 2014