The 234U/238U activity ratio as an indicator of redox surface in the Allouga Quarry face, Southwestern Sinai, Egypt.

The 234U/238U activity ratio can be used to delineate the last redox surface between the lower and middle members of Um Bogma Formation in Allouga Quarry, southwestern Sinai, Egypt. The activity concentrations of radionuclides were measured for nine samples collected from the base to top of the geologic section. The 234U/238U activity ratio was used to express the oxidation or reduction prevailing. The lower (base) samples showed oxidation state, while the upper (top) samples showed reduction state. From uranium age results, the uranium leaching process in lower member is more recent than the uranium accumulation process in middle member. [ABSTRACT FROM AUTHOR]