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Vojin Gordanic, Geological Institute of Serbia (Serbia and Montenegro)
Aleksandra Ciric, Geological Institute of Serbia (Serbia and Montenegro)
Dragan Jovanovic, Geological Institute of Serbia (Serbia and Montenegro)
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Contents of natural radionuclides (uranium, thorium, potassium) as well as radon (Rn-222) concentrations in different geological milieus (igneous and sedimentary rocks) of Southern Serbia are presented in this paper. Areas with anomalous concentrations of radon is soils taken from smaller settlings or from their vicinity were selected.
Uranium mineralizations were detected in coarse-grained sediments (breccias-conglomerates, conglomerates and sandstones) of Tertiary-Palaeogene Pcinja basin. The anomalous uranium contents are connected with limonitized sandstones and they reach values up to 120 g/t. Radon concentrations measured from the soils of Zbevac during detailed geochemical investigations reach values over 110 Bq/l. Results are presented on adequate geochemical map.
Another selected area is placed within Bujanovac granitoide massif in the draining area of Bujanovac River and Moravica River. Natural radionuclide contents are detected by detailed geochemical investigations on the location that is built of plagiogranites and dark-red clays. Obtained values are: in the weathered plagiogranites for ΣU=1.1 ppm, for Th-232 =3.18 ppm, for ΣK= 0.91% (wt), and in dark-red clays for ΣU=2.71 ppm, for Th-232=9 ppm and for ΣK= 0.95% (wt). Radon concentrations in soil were measured during geochemical investigations and they range in interval from 3.7 to 57.37 Bq/l, with average of 9.6 Bq/l. Results of these investigations are presented on the corresponding geochemical map.
Within the Vardar zone, which belongs to the Serbo-Macedonian mass, area selected for investigations was the Stublovaca area in vicinity of Binacka Morava River. Geologically, this area consists of volcanogenic-sedimentary rocks (trachytes and trachytic sandstones). Contents of natural radionuclides in them range within interval from 15-23 g/t for ΣU , 55-68 g/t for Th-232 and 5.2-6.3 % (wt) for ΣK. Radon concentrations in soils were measured during detailed emanometric examination and obtained values were over 740 Bq/l. Results of these investigations are also presented on the adequate geochemical map.
Taking in to the consideration the fact that there are settlements on selected areas, the results of hidrogeochemical, metallometric, lithogeochemical, atmogeochemical and biogeochemical investigations are of special interest for defining areas of geochemical endemics and for population protection.
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