Earth’s Cryosphere, 2019, Vol. XXIII, No. 6, p. 7-15

CRYOGENIC MINERAL FORMATIONS IN THE CAVES OF PRIOLKHONIE REGION (WESTERN PRIBAIKALIE)

E.P. Bazarova1, O.I. Kadebskaya2

1 Institute of the Earth Crust, SB RAS, 128, Lermontova str., Irkutsk, 664033, Russia; bazarova@crust.irk.ru
2 Mining Institute, UB RAS, 78a, Sibirskaya str., Perm, 614007, Russia; icecave@bk.ru

The paper provides insights about cryogenic mineral formations in four caves with perennial and seasonal aufeis occurrences studied in the Western Pribaikalie (Fore-Baikal) region. The study revealed that calcite and ikaite, its metastable phase, predominate in the cryogenic material, while gypsum and chalcedony are present in minor amounts. The differences in morphology of the cryogenic mineral formations were described with regard to the internal facial conditions controlling mineral formation. The δ13C and δ18O isotope composition of calcite cryogenic powder and calcite pseudomorphs after ikaite was determined. Their analysis revealed that the isotopic composition of pseudomorphs may be either similar to calcite powder, or differ significantly from it (the pseudomorphs are characterized by lighter isotopic composition of oxygen and carbon). Such difference established in the composition of ikaite from Malaya Baidinskaya cave is explained by the mineral formation under slow-freezing conditions.

Caves, cryogenesis, Western Pribaikalie, calcite, ikaite, coarse-grained cryogenic cave carbonates

DOI: 10.21782/EC2541-9994-2019-6(7-15)