The Peshnevo Formation (Early Pliocene) palynology in southern Western Siberia

Neogene sediments are widespread in the southern West Siberian Plain. Limited data on the Pliocene palynology were obtained mainly in the second half of the 20 th century and have poor stratigraphic correlation. The Peshnevo Formation is one of such frontier units. The eponymous faunal complex of the Early Ruscinian with the index species of Promimomys antiquus (MN14 Zone, 4.9–4.2 Ma) characterizes the formation. Formerly these sediments were dated from the Lower Miocene to the Upper Pliocene. Previous studies suggest no data on the Peshnevo level palynoflora. Three new small mammal sites of the Peshnevo level were studied near Irtysh and Om rivers (Omsk region). The pollen analysis data indicate the pre-dominant forest-steppe environment. Arboreal pollen accounts for up to 45 %, indicating local mixed forests with dark coniferous and broad-leaved species. Thus, the paper presents the first palynological characteristics of the Peshnevo Formation sediments, which include a reliable paleontological correlation with small mammals.