“…The examination of the exemplary curve (Figure 3) indicates that the specific activities of 226 Ra, 238 U, 232 Th, 214 Pb, 235 U, and 40 K in the oil shale deposits are not related to depth and the irregular recorded variation seems to be related to the lithological factors which probably control the radionuclides' distribution. (14). The S1 (16) shows the highest value of 232 Th and 40 K while S1 (10) indicates the highest value of 214 Pb.…”