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Integrated stratigraphy of the reference sections for the Callovian-Oxfordian boundary in European Russia

Kiselev D., Rogov M., Glinskikh L., Guzhikov A., Pimenov M., Mikhailov A., Dzyuba O., Matveev A., Tesakova E.

Volumina Jurassica

2013

Vol. 11, no. 1

59–-96

The most complete succession of the Callovian-Oxfordian boundary recorded in European Russia is the Dubki section, where the authors have carried out integrated paleontological and magnetostratigraphical studies. A continuous sequence of the West-European biostratigraphic units in the interval from the Lamberti to the Cordatum Zones is present in this section, and 10 ammonite biohorizons have been recognized. Additional data concerning nannofossil assemblages, foraminifers, ostracods, belemnoids and the paleomagnetic polarity for the Dubki section are also presented. The Callovian-Oxfordian boundary, marked by FAD of the genus Cardioceras, is placed at the base of the scarburgense biohorizon. The paleontological richness and continuity of the succession make the Dubki section a possible GSSP candidate for the Callovian/Oxfordian boundary. Correlation of the Dubki ammonite succession with those of the other GSSP candidates, Redcliff Point and Thuoux, is proposed. Other sections studied in Russia have yielded some additional observations on the Callovian-Oxfordian boundary beds. Although in the Dubki section the praemartini biohorizon is not found, its existence is proved, however, in Orenburg region (Khanskaya Gora). In the Datchovskaya section (Northern Caucasus) the paucicostatum biohorizon is characterized by an unusual combination of Subtethyan and Boreal ammonites, including Kosmoceras, which is not typical of the paucicostatum biohorizon outside the Northern Caucasus.

Correlation of the Barremian belemnite successions of northwest Europe and the Ulyanovsk - Saratov area (Russian Platform)

Baraboshkin E. J., Mutterlose J.

Acta Geologica Polonica

2004

Vol. 54, no. 4

499-510

The marine sedimentary successions of Barremian age yield, both in northwest Europe and on the Russian Platform, diverse and abundant belemnite faunas. These include the genera Praeoxyteuthis, Aulacoteuthis and Oxyteuthis and are attributed to the boreal belemnite family Oxyteuthididae. The Oxyteuthididae are endemic to northwest Europe (northern Germany, northeast England, North Sea) and the Russian Platform, where they evolved in isolation. They possibly derived from the belemnite genus Acroteuthis in Late Hauterivian time. Phylogenetically they are interpreted as the latest off shoot of the Belemnitina, which became extinct in the Early Aptian. Since ammonites are extremely rare on the Russian Platform oxyteuthid belemnites have been used to establish a biozonation scheme with seven belemnite zones (from bottom to top):Praeoxyteuthis hibolitiformis Zone (Early Barremian), Praeoxyteuthis jasikofiana Zone (Early Barremian), Praeoxyteuthis pugio Zone (earliest Barremian), Aulacoteuth is descendens Zone (late Early Barremian), Oxyteuthis brunsvicensis Zone (early Late Barremian), Oxyteuthis germanica Zone (Late Barremian), and Oxyteuthis lahuseni Zone (latest Barremian/Aptian). Apart from the O. lahuseni Zone this zonation can be correlated to the well established belemnite scheme of northwest Europe, allowing a detailed correlation of the Barremian of both areas.