Mojzeš A., Andrássy E., Nogová E., Ondrášová L. & Marko F., 2025: Uranium occurrences as landfill residuum after closed mining in the Kravany area (Kozie chrbty Mountains, Western Carpathians, Slovakia). Acta Geologica Slovaca, 17, 1, 17–25.

Uranium occurrences as landfill residuum after closed mining in the Kravany area (Kozie chrbty Mountains, Western Carpathians, Slovakia)

Andrej Mojzeš¹, Erik Andrássy¹, Ema Nogová², Lenka Ondrášová² & František Marko³

¹Department of Engineering Geology, Hydrogeology and Applied Geophysics, Faculty of Natural Sciences, Comenius University Bratislava, Ilkovičova 6, SK-842 15 Bratislava, Slovak Republic; andrej.mojzes@uniba.sk, andrassy4@uniba.sk
²Earth Science Institute, Slovak Academy of Sciences, Dúbravská cesta 9, SK-840 05 Bratislava, Slovak Republic; ema.nogova@savba.sk, lenka.ondrasova@savba.sk
³Department of Geology and Paleontology, Faculty of Natural Sciences, Comenius University Bratislava, Ilkovičova 6, SK-842 15 Bratislava 4, Slovak Republic; frantisek.marko@uniba.sk

Abstract

The Kozie chrbty Mountains are known for their potential for uranium deposits and mineral occurrences, many of which have been mined and exploited in the past. Pilot ground gamma-ray spectrometry measurements along six profiles crossing the Vikartovce fault map trace were carried out in the north-east vicinity of the village of Kravany to specify its position in the field. Extremely high radioactivity values were measured especially the absorbed dose rates and uranium concentrations. The results of an additional eleven rosette-shaped profiles at the three most radioactive sites confirmed the high values. The average values of the absorbed dose rate (136.4 nGy.h^-1) and the uranium concentration (8.8 ppm eU) in the studied location greatly exceeded the average values for the rocks of the Western Carpathians, 63.3 nGy.h^-1 and 3.3 ppm eU, respectively. The maximum measured values of 1482.6 nGy.h^-1 and 223.9 ppm eU were on the order of 10- to 100-times higher than the average values. In the case of potassium and thorium, the average values were exceeded only rarely and not as significantly. The cause of the increased and high values of radioactivity of the rock and soil environment are the remnants of uranium mining as well as the reclamation of mining facilities and activities. The radioactively contaminated near-surface horizon over an area of more than 2000 square meters of the studied location may pose a significant health risk to people potentially staying in the area during the annual cycle. This information should be evaluated when planning future human activities in the area studied.

Key words: Western Western Carpathians, Kozie chrbty Mts., Permian, uranium deposit, landfill, remediation, gamma-ray spectrometry

Manuskript doručený: 2025-06-04

Manuskript revidovaný: 2025-07-14