GROUND GAMMA-RAY SPECTROMETRIC SURVEY OF SOME URANIUM ANOMALIES, EAST ABU-ZENEIMA AREA, SOUTHWESTERN SINAI, EGYPT

The aim of this work is to conduct a ground follow up for four airborne g-ray spectrometric anomalies
located in east Abu-Zeneima area, southwestern Sinai, Egypt. To achieve this goal, the selected localities
were first geologically studied, then field g-ray spectrometric measurements were carried out along a
number of profiles, in a direction at high angle to the main structural and radiometric features.
Four horizons in the Paleozoic section were identified with high uranium contents. They include Gabal
(G.) Khamela, Ramlet Homayer, G. Homayer and G. Ghorabi, all are characterized by high uranium
anomalies. The older horizon represents the top most parts of Adadia Formation and is represented by
a highly ferruginous sandstone bed which is recorded in G. Khamela, Ramlet Homayer and at the base
of G. Homayer. The second horizon is located in Adadia Formation and is represented by sandstone
which recorded in G. Ghorabi. The third horizon is the yellowish and whitish sandstone of El-Hashash
Formation at G. Homayer and very close to the doloritic dyke situated at its eastern side. The fourth horizon
is located at Magharet El-Maiah Formation and is represented by shale and kaolin at G. Homayer.
G. Khamela zone shows high eU/eTh ratios reaching more than 9.5, which are associated with the
Adadia sandstone and display elongated E-W and NW-SE trends. There are high eU/eTh anomalies in
the Ramlet Homayer zone, which reach more than 5 in value and represented by ferruginous sandstone of
Adadia Formation. The excavated trenches situated at the contact between Adadia sandstone and the
basic dyke in the G. Homayer anomalous zone are characterized by high eU/eTh ratio reaching 12.5. The
significant anomalies of eU/eTh ratio in the G. Ghorabi zone reached 3 in value and possess different
shapes. They are distributed in the siltstone, which is controlled by NW-SE trend.