Chemical Composition of Vendian Mudrocks (Middle Urals) and Some Quantitative Features of Paleoclimate

Lithogeochemical features of the Vendian nonglacial mudrocks (Serebryanka and Sylvitsa groups) in the Middle Urals indicate that average annual temperatures in paleocatchment areas during their accumulation varied from 4 to 21°C. Such temperatures comply mainly to the temperate and temperate-warm, but less often warm climates. The calculated RW index values also suggest that paleoclimate in the Vendian catchment areas was generally temperate. At the same time, some mudrock samples of the Garevka, Kernos, and Perevalok formations, as well as the Kobylii Ostrov Member of the Chernyi Kamen Formation, have RW index values comparable to those of modern continental or subarctic climate. Variations in RW index values and reconstructed MAP values demonstrate similar cooling/warming trends for mud rocks of Vendian nonglacial intervals in the Middle Urals.