Radioactivity of Outcropping Rock Formations / Iraqi Southern Desert

Abstract

The study area located between latitude (29^o-31^o) N and longitudes (42^o-47^o) E within the Mesopotamian zone inside Stable and Unstable Shelves. Airborne radioactivity survey of Iraq prepared by French Company (C.G.G.), (1974) was used to acquire the total count readings on a scale of 1:200.000 for Iraqi southern Desert. A regional radio-geological study was carried out to determine the relationship between various radioactive levels and the general structural and geological framework in the study area. The natural radiation background was calculated using trend surface analysis method, it ranged between (890) cps in Hour Al-Hammar region and (1160) cps in Iraqi-Saudi border of the area. The total radioactivity of the exposed geologic units and formations were ranged between (800_900) cps in Dibddiba Formation and (1100_1200) cps in Umm Er-Radhuma Formation, as well as that for Quaternary deposits it was found between (700_900) cps in slope deposits in Al-Salman region and (1100_1300) cps in valley fill deposits in Middle Member of Dammam Formation. Six sites of radiometric anomalies were noticed in the third order residual anomaly map. After the analysis of available geologic, structure and geophysical information of the study area, the nature and cause of these normally occurring anomalies and their relations with the mineral and lithological constituents of the rocks and their relation to the structural and geologic setting of the region was established and analyzed.