Core-samples from wells and an outcrop located on the Voronesh Anticline
in the southeastern part of the Russian Platform contain Late Cretaceous
radiolaria. 83 species are described and illustrated (SEM and
transmitted light images) from Santonian-early Campanian deposits, and
two assemblages are distinguished. The older assemblage with Alievium
gallowayi, Archaeospongoprunum bipartitum, Archaeospongoprunum. cf. A.
salumi as well as other less age-diagnostic taxa, is interpreted as
Santonian correlative with the Euchitonia santonica-Alievium gallowayi
Assemblage Zone of the Moscow Basin (Vishnevskaya 1993). The younger
assemblage, of Santonian - early Campanian age, contains Patulibracchium
cf. P. davisi, Crucella irwini, Cryptamphorella sphaerica,
Praeconocaryomma californiensis, Dictyomitra lamellicostata among other
species and is correlative with the Orbiculiforma quadrata-Lithostrobus
rostovtsevi Assemblage Zone of the Moscow Basin. In terms of
inter-regional faunal comparisons, both of the Voronesh Anticline
radiolarian assemblages demonstrate relatively close affinities to
coeval rocks from the Volga River region, but less similarity to the
assemblages from the Moscow Basin. Only a few of the common endemic
species of Siberian assemblages occur in our samples. On an
inter-regional level, the radiolarian assemblages described herein have
similarities with assemblages reported from Japan and California.
Index-species characteristic for the Santonian-Campanian radiolarian
biozonations of the Atlantic and Pacific Oceans are not found in our
collection. However, the presence of many cosmopolitan species known
from the European Platform, Japan and California suggests a marine
connection between the Voronesh Anticline region, the western Atlantic
and eastern Tethys during Santonian-Early Campanian time.