... radionuclides depend on the type of mother wall from which the soil was formed.
The concentration of uranium and thorium is high in magmatic walls (eg granite), but also in
some sedimentary walls (shards and phosphate walls). According to the UNSCEAR (2000)
report, the mean concentrations of activity ...
Vladimir Simić, Rade Jelenković, Dragana Životić. "Mineral Resources of Serbia: Environmental, Societal and Economic Challenges" in Serbia: Current Issues and Challenges in the Areas of Natural Resources, Agriculture and Environment,, Nova Science Publishers, Inc. (2019)