Search Results

You are looking at 1 - 2 of 2 items for

  • Author: Ekaterina M. Tesakova x
Clear All Modify Search
Open access

Maria S. Karpuk, Ekaterina A. Shcherbinina, Ekaterina A. Brovina, Galina N. Aleksandrova, Andrey Yu. Guzhikov, Elena V. Shchepetova and Ekaterina M. Tesakova

Abstract

Previous studies made in different parts of the world have shown that Barremian–Aptian times imply many difficulties in deciphering the biostratigraphy, microfossil evolution and correlation of bioevents. In an attempt to improve our knowledge of this period in a particular area of the Tethyan realm, we present the first integrated study of microbiota (including planktonic foraminifera, calcareous nannofossils, ostracods and palynomorphs) and magnetostratigraphy of the upper Barremian–Aptian sediments from south-eastern Crimea. The nannofossils display the classical Tethyan chain of bioevents in this interval, while the planktonic foraminifera demonstrate an incomplete succession of stratigraphically important taxa. Our study enabled the recognition of a series of biostratigraphic units by means of four groups of microfossils correlated to polarity chrons. The detailed analysis of the microfossil distribution led to a biostratigraphic characterization of the Barremian/Aptian transition and brought to light an interval, which may correspond to the OAE1a.

Open access

Alexey S. Tesakov, Vadim V. Titov, Alexandra N. Simakova, Pavel D. Frolov, Elena V. Syromyatnikova, Sergey V. Kurshakov, Natalia V. Volkova, Yaroslav I. Trikhunkov, Marina V. Sotnikova, Sergey V. Kruskop, Nikita V. Zelenkov, Ekaterina M. Tesakova and Dmitry M. Palatov

Abstract

Late Miocene continental deposits overlying the Khersonian marine sediments near the city of Maikop bordering the Belaya River (North Caucasus) yielded a diverse biotic record including palynology, ostracods, fresh-water and terrestrial molluscs, fishes, amphibians and reptiles, birds, and mammals. The obtained data indicate predominantly wooded landscapes along the banks of a large fresh-water estuarine or lagoonal basin with occasional connection with the sea. The basin existed in a warm temperate to subtropical climate with a high humidity and an estimated mean annual precipitation above 800 mm. The mammalian assemblage with Hipparion spp., Alilepus sp., Paraglirulus schultzi, Eozapus intermedius, Parapodemus lugdunensis, Collimys caucasicus sp. nov., Neocricetodon cf. progressus, etc. is referable to the early Turolian, MN 11. The data regarding composition and stage of evolution of the small mammal content combined with mostly normal polarity of the fossiliferous deposits, and the age estimates of the upper Khersonian boundary as between 8.6 and 7.9 Ma indicate a plausible correlation with Chron C4n and an age range between 8.1–7.6 Ma.