Geophysical Radioactive Environmental Anomaly in WadiShatti area South Central LIBYA

By: Bashir Youshah

Department of Geophysics – Faculty of Science – University of Tripoli

Issue: Vol 21 |First Issue | 2015

article language: English

Abstract:

An airborne geophysical survey measuring gamma-ray spectra and the earth's magnetic field was conducted in the Wadi Shatti area in south-central Libya at the end of the last century. The area was previously known to contain sedimentary lenses of iron ore. The primary objective of the geophysical survey was to explore the mineral potential of the area. Some of the radioactive anomalies recorded by the gamma-ray spectrometer were analyzed to determine the equivalent uranium (eU), equivalent thorium (eTh), and equivalent potassium (eK) of these anomalies. Surprisingly, some of these anomalies were located at sabkhas and swamps fed by artesian springs resulting from groundwater flow. A high level of radioactivity was found at one artesian spring, with scintillometer measurements showing an activity of 1500 counts per second. This radioactivity could be attributed to the geological formations carrying the groundwater, disequilibrium in the decay of various radioactive series, subsurface phosphate layers, phosphate fertilizers, or other reasons. Regardless of the cause of this notable radioactivity, some of the natural springs in the area are used for drinking water and irrigation. Although some of these anomalies are located in remote desert areas, they should be considered environmental geophysical anomalies and studied in detail with follow-up, including monitoring the health records of the population in the areas where these anomalies are located.