Natural radioactivity and geochemical aspects of radioactive mineralisation in El Sela, South Eastern Desert, Egypt

ABSTRACT

The natural radioactivity data revealed that eU reached up to 157.4, 1625 and 178 ppm in microgranite and dolerite dikes as well as japer vein, respectively, whereas the two-mica granite possesses the higher eTh-contents up to 53.8 ppm. Mineralogically, the two-mica granite is enriched in thorite, brockite and uranothorite, whereas uraninite and coffinite are recorded in dolerite, and the latter one is recorded in microgranite, bostonite and jasper. Primary uranium minerals as uraninite and coffinite could be a source for uranium enrichment and the formation of secondary uranium mineralisation. Uranium mobilisation was active towards the two perpendicular shear zones having NNW-SSE and ENE-WSW rejuvenated trends. Successive hydrothermal alterations play their role in the formation of uranium ore deposits to be trapped in post-granitic dikes.

KEYWORDS:

• Natural radioactivity
• uranium
• thorium
• mineralogy
• shear zone
• El Sela

Acknowledgments

The authors would like to express their gratitude to members of Geomodel Research Center, Saint Petersburg State University, Saint Petersburg, Russia for their assistance in scanning electron microscope and electron microprobe. The authors would like to thank Yuriy V. Erokhin at the Institute of Geology and Geochemistry (IGG) of the Ural Branch of the Russian Academy of Sciences, Chairman of the Ural Branch of the Russian Mineralogical Society for valuable discussion, constructive comments and revising this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).