Radon activity of faults (western Baikal and southern Angara areas)

We report results of transect radon surveys on twenty six large and small faults of different geometries in the western Baikal and southern Angara (southern Siberian craton) areas. The studied faults show up in the radon field as broad zones of high radon activity concentration, with their widths 1.4 times the widths of faulting-related deformation zones. Other things being equal, radon emanation depends on the size and slip geometry of faults and on their activity in the Cenozoic. Relative radon activity is higher in rift faults than in cratonic ones, in normal relative to strike-slip faults, and in larger and more active faults, the latter factor being the basic geodynamic control of radon emanation.