Investigating the Pollution of Radioactive Elements Based on Airborn Radiometric Geophysical Measurements in Goljeh (Zanjan province)

The study area is located in the southeastern quarter of Hashtjin 1:100000 geological map in Zanjan province. The area is located in both Eastern Alborz and Central Iran geological settings and known as Gollejeh/ Gulluja region. A wide spectrum of extrusive and intrusive igneous rocks as well as volcanoclastic sediments are exposed in the investigated area. Structural elements such as faults along with lithological heterogenities led to differential erosion and creation a various topography. The aim of the study is to measure the contamination of the radioactive elements of uranium, thorium and potassium in such geological setting. A total of 52107 samples were systematically gathered by airborn radiometric geophysical method. Statistical analysis and iso-concentrational mapping overlain on the satellite and geological map of the area show that the high concentration of these radioactive elements is generally associated with the igneous rocks such as granitic rocks distributed in the eastern part of the study area (e.g. Varmaziarabd village). The low concentrations of the U, Th and K could mainly be observed over volcanoclastic rocks in the middle parts of the study area (e.g. Habash and Tristan villages). Average concentration of the radioactive elements does not show a serious contamination in the area, while the maximum concentration of the thorium elements exceeds the standard of WHO.