Em. Elkattan et al., GROUND GEOPHYSICAL-STUDY FOR DEVELOPMENT AND EXPLORATION OF EL-MISSIKAT RADIOACTIVE MINERALS PROSPECT, CENTRAL EASTERN DESERT OF EGYPT, Nuclear geophysics, 9(4), 1995, pp. 363-382
Citations number
NO
Categorie Soggetti
Geosciences, Interdisciplinary","Mining & Mineral Processing","Nuclear Sciences & Tecnology
The El Missikat area lies in the Eastern Desert of Egypt, 85 km west o
f Qena town. The area being studied is covered mainly by pink granite,
quartz-diorite rocks and wadi deposits. The importance of the area or
iginates from previous studies, including airborne geophysics, surface
geology and mining geology which indicate that the area has features
of radioactive mineralization at the northeastern periphary of G. El M
issikat. The present study deals with the use of ground geophysical me
thods (total-count radiometric and magnetic) in the exploration of rad
ioactive mineralization acid their relation to the geology and structu
ral pattern of the area. The ground total-count radiometric method is
used to describe the radioactivity of different rock units and the con
struction of the standard deviation (or anomaly) contour map to define
the anomalous radioactive zones. Eight prominent radioactive anomalie
s were outlined from this study and they represented targets of high p
riority for ground follow-up. Accordingly, to emphasize the extension
of the anomalous zones at the subsurface, gamma-ray logging was carrie
d out on a total-count basis in one inclined drill hole (120 m depth)
with dip angle 29 and azimuth N20 degrees W at a selected location. In
addition five subsurface radiometric anomalies were identified by gam
ma-ray logging interpretation. The interpreted radioactive anomaly No.
IV is considered a good indication of the subsurface continuity of a
surface mineralized zone associated with the silica vein which was geo
logically mapped at the north of El Missikat well number II. Meanwhile
, the total magnetic intensity survey was used to delineate the major
structural Features. The results of this study revealed the presence o
f six major, deep-seated faults, five basement tectonic blocks, basic
or/and acidic zones, near-surface faults, contact between granite and
quartz-diorite and several shear zones as well as dykes and veins. The
integration between results of these two methods guided the developme
nt of exploration and solved many problems that were obscure for the f
ield geologists and mining works in the area studied. It could also he
lp in defining the radioactive mineralized zones, and their setting in
depth. Also, it was observed that the interpreted radioactive anomali
es are associated with acidic shear zones which may be due to hydrothe
rmal solutions that percolated through, or around, these shear zones.