Earth’s Cryosphere, 2024, Vol. XXVIII, No. 4, p. 23-32.
SURFACE AND GROUND WATERS IN TERRESTRIAL PERMAFROST REGION
SUBPERMAFROST GROUNDWATER IN THE NORTHEASTERN PART OF THE LENA–AMGA INTERFLUVE
M.A. Fedorov*, A.A. Fedorov, N.A. Pavlova
Melnikov Permafrost Institute, Siberian Branch of the Russian Academy of Sciences, Merzlotnaya St. 36, Yakutsk, 677010 Russia
*Corresponding author; e-mail: FedorovMA@mpi.ysn.ru
The purpose of this work was to specify the hydrogeological conditions in the poorly studied north-eastern part of the Lena–Amga interfluve. We analyzed archival (1965–1995) and published data on subpermafrost waters and permafrost thickness in the Churapcha and Tattinsky districts of the Republic of Sakha (Yakutia), including new field studies (2009–2022). The research was based on the data from 19 groundwater exploration boreholes, 450 to 650 m in depth. It is shown that the Jurassic and Middle Cambrian aquifer complexes differ in piezometric pressures and chemical composition. Based on the new information, it is suggested to shift the estimated boundary of fissured formation groundwater occurrence in terrigenous carbonate sediments northwards by 50–80 km. A zone with distinct hydrogeological conditions near the Tatta–Tompo fault was identified. Presumably the fault was formed under conditions of horizontal compression, which resulted in compaction of rocks, which reduced permeability along the fault, and increased freezing intensity in strata with low water content during periods of decreased global temperatures.
Keywords: groundwater, Middle-Cambrian aquifer system, Jurassic aquifer system, Tatta–Tompo fault, hydrostatic level, chemical composition.
Recommended citation: Fedorov M.A., Fedorov A.A., Pavlova N.A., 2024. Subpermafrost groundwater in the Northeastern part of the Lena–Amga interfluve. Earth’s Cryosphere XXVIII (4), 23–32.
Received January 5, 2024
Revised March 31, 2024
Accepted April 16, 2024
Translated by S.B. Sokolov