الفهرس | Only 14 pages are availabe for public view |
Abstract The main objectives of this study were to provide digital, high resolution ground gammaray spectrometric data in hand with total magnetic intensity field and VLFEM data to enhance existing bedrock and surficial geological mapping and mineral exploration program for the two Ubearing prospective areas in the Eastern Desert (Kab Amiri Episyenite and Sela Shear zone) for direct detection of their uranium deposits. The formation of the Kab Amiri episyenite may be related to NESW as well as EW extensional fractures. The episyenite zone appears to be the most favorable reservoir for uranium mineralization, due to the presence of a large part of its volume full of free vugs reaching up to 30% empty volume. The increase of U and their ratios versus stability of the Th values in the episyenite proved the enrichment of the uranium due to the remobilization and reconcentration of U through the hydrothermal alteration. However, the episyenitic bodies representing highly permeable conduits, deep drilling is required to evaluate the possible uranium resources of these zones. The structures, which are interpreted from the magnetic data, are characterized by four intersecting sets of faults trending in the EW, NWSE, NNWSSE and NESW directions. The EW trending set of faults is older than the NWSE trending set, where the later dissect and displace the former. Sela shear zone is clearly delineated on the various <U+F067>ray spectrometric maps. These maps show that the sheared lamprophyre is clearly detected from the sharp increase in the eU values and marked decrease of the K and eTh values. These patterns can be used to improve the lamprophyre dykes have higher Ucontent, many times greater than the granite, leading to an increase in the Upotentiality of the study area. These dykes may eventually have played an important role as a heat source, which may have led to Umobilization and possibly local uranium entrapment in the study area. The magnetic and apparent conductivity maps clearly exhibit distinctive anomalies over Sela shear zone, particularly in the central parts of the study area, where the sheared lamprophyre is associated with high magnetic susceptibilities and high electric conductivities. The stacked profiles of highresolution ground gammaray spectrometric, magnetic and VLFEM data are illustrated for a chosen geologic crosssection, to enhance the existing bedrock and surficial geological mapping, for the uranium exploration program in the two studied areas. The magnetic results indicate that the expected extension of the Kab Amiri granitic intrusion towards the east however, it underneath by basic rocks towards the west. This suggests determining the locations of drilling to the east and northeast of the granitic intrusion. The association of a spectrometry, magnetic and conductivity anomaly for the Sela shear zone would be sufficient indication to that target as one of the most promising uranium vein type in Egypt representing a good trap for Urich fluids or U ores and it will be promising for drilling. |