Radiolarians from Santonian–Campanian reference sections of Saratov Povolzhie and correlation of subdivisions on calcareous nannoplankton, foraminifers, and radiolarians

The radiolarian assemblages from the Santonian — Campanian siliceous sediments in Pudovkino, Lysaya Gora and Nizhnyaya Bannovka sections in the Saratov Povolzhie are described. Various correlations of the radiolarian biozones with ones based on calcareous nannoplankton and benthic foraminifers are discussed. Radiolarians are especially important for age identification and correlation of the Upper Cretaceous siliceous successions.