Abstract
Sedimentary rock geological and radioactivity studies are important for their use as raw materials in the construction industry. Six samples were collected from south of Hail at the east and north of the Arabian Shield of Saudi Arabia. Their coordinates between Lat. N: 26 degrees 04'09.1 to N: 28 degrees 59' 01.3 '' and long. E: 43 degrees 35'16.1 '' to E: 45 degrees 19'59.3 ''. Samples were analyzed by XRD for the mineral constituents. X-RD results give the major, minor and trace minerals, the major mineral is calcite (CaCo3), Dolomite (CaMg(CO3)(2)), and Quartz(SiO2), with minor and trace concentrations. Also, the dried samples were analyzed by atomic absorption spectrometer for the Al, Ca, K, Bi, Pb, andTh, concentrations in ppm and/or percent. Results give concentrations in percent and ppm ranging from 0.10 to 0.68, 3.16 to 33.53, and 0.13 to 0.31 in %, and <10, <7.5 to 1756.38, and <1 in ppm respectively. Using high-resolution gamma-ray spectroscopy, the activities concentrations Bq/.kg dry weight for the U-238, Ra-226, Th-232, U-235 and K-40, ranged from 176.10+/-0.07 to 222.86+/-0.21, 28.34+/-0.11 to 231.04+/-0.05, 08.66+/-0.17 to 137.84+/-0.04, 09.35+/-0.03 to 12.69+/-0.03, 78.27+/-0.23 to 202.21+/-0.04 with mean values 199.18 +/-0.17, 109.01 0.07,37.96+/-0.10, 11.47+/-0.02, and 123.57+/-0.13 respectively. For theRa(Eq) (Bq/kg) ranged from 59.193 to 438.615 with mean value 172.810 which is lowr than 370Bq/kg, the permissible limit (UNSCEAR, 2000). The mean values of the annual effective dose (D-eff(mSv/y) was found to be less than one (0.096) which is within the worldwide mean values(<1for D-eff (mSv/y) (UNSCEAR, 2000). [AfafA. Fakeha. Activity Concentrations of Natural Radionuclides in Sedimentary Rocks from North of Arabian Shield (Hail), Saudi Arabia. Life Sci J 2012;9(4):5610-5614] (ISSN: 1097-8135). http://www.lifesciencesite.com. 835