Planktonic foraminifers and radiolarians from the Coniacian-santonian deposits of the Mt. Ak-Kaya, Crimean Mountains, Ukraine

Cenomanian–Campanian (Late Cretaceous) planktonic assemblages of the Crimea–Caucasus area: Palaeoceanography, palaeoclimate and sea level changes

“…The evolution of new k-strategists and their maximum diversification may reflect more stable, oligotrophic conditions (Spezzaferri and Spiegler, 2005). The planktonic foraminifera that characterized the early Turonian and most of the Santonian in the study area represent assemblages compatible with Tethyan conditions (Tur et al, 2001;Kopaevich, 2010;Korchagin et al, 2012;Bragina et al, 2014). marginotruncanids by globotruncanids, appear to be related to a cooling episode (Petrizzo, 2002;Huber et al, 1995Huber et al, , 2002Spezzaferri and Spiegler, 2005;Hay, 2008).…”

“…The evolution of planktonic foraminifera from the Cenomanian to the Campanian is characterized by an increase in species diversity and morphological complexity (Bandy, 1953(Bandy, , 1961Bolli, 1959;Borsetti, 1962;Maslakova, 1978;Caron, 1985;Gorbachik, 1986;Krasilov, 1986;Sliter, 1995, 1999;Hart, 1999 (1978), Samyshkina (1983), Plotnikova in Astakhova et al (1984), Tur (1996), Tur et al (2001), Korchagin, 2001;Kopaevich (2009), and Korchagin et al (2012). The Albian-…”

“…The Cenomanian-Turonian transition of Selbukhra has been described by Bragina and Bragin (2007). The TuronianConiacian of the Bel'bek River has been described by Bragina et al (2014) and the Turonianlower Coniacian of the Biyuk-Karasu by Korchagin et al (2012), which also includes the Santonian of Mt. Ak-Kaya.…”

“…The Marginotruncana pseudolinneiana IRZ (Pessagno, 1976) Robaszynski and Caron (1995): this zonal species is very rare, or absent, in the study area (Korchagin et al, 2012).…”

“…It is the primary criterion for the definition of the GSSP for the base of the Santonian stage (Lamolda et al, 2014). As a result of the acme of Neosciadiacapsa diabloensis Pessagno, this interval can be compared with the Santonian of the Ak-Kaya section in the Crimea (Korchagin et al, 2012) and the Voronezh Region of Russian Platform (Popova-Goll et al, 2005). Assemblage VI, with the Globotruncanita elevata PRZ and…”