Publisher © Czech Geological Survey, ISSN: 2336-5757 (online), 0514-8057 (print)
Soil gas radon and proximity to fault systems in the Czech Republic
AbstractThe soil gas radon (222Rn) values and their dependence on proximity to faults was studied on 9300 Rn measurements and 33131 detected vectorised faults within the Czech Republic using ArcGIS 8.3 programme. The proximity to faults influences only the mean and range of maximal values on the test sites classified as high radon index (decrease of parameters with interval distance 0-50, 50-100, 100-150 m from the detected fault). Maxima over 200 kBq . m-3 were observed in the eastern margin of Bohemian Massif in a lithologically and radiometrically homogeneous area of Culm sedimentation. These maxima are situated in the close vicinity of tectonically active faults oriented NW-SE and WNW-ESE (W-E). The recent geodynamic activity of the latter fault system is evidenced by GPS satellite measurements (vectors of movements caused by stress of Carpathian belt). Thus, the spatial investigation of soil gas radon maxima related to faults can contribute to studies of recent neotectonic activity of fault structures in the Bohemian Massif.