Characteristics of secondary deposits in the Starateley cave (Sverdlovsk Region)

The paper reports, for the first time, on cryogenic minerals and flowstones in the Starateley cave on the River Sosʼva (the Northern Urals). The cave was found and explored in 2011; presently it is one of the largest, in terms of its volume, underground caverns in the Sverdlovsk Region. Upon our visit in 2016 in addition to «common»speleothems, such as cryogenic flour and flowstone, we have found peculiar aggregates of yellowish calcite as well as cave pearls. The depleted O and enriched C isotope signatures indicate cryogenic origin of this calcite and its formation from slowly freezing solution. Dating cryogenic calcite with ²³⁰Th/²³⁴U method allow to constraint the time of climate warming-related thawing of permafrost on the eastern slope of the Northern Ural Mountains to 85.4 ± 0.5 ka BP. The age of cave pearls is Holocene (7.4 ± 2.1 ka BP). Stalagmite sample has not been dated due to low U contents and inferred «open system» behavior of U and Th isotopes.