الفهرس 
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Abstract
The present thesis aims to study the styles of lode gold deposit at a selected area in
the extreme south Eastern Desert of Egypt and to define vectors for this type of
mineralization styles.
A verified geological/structural mapping carried out using the satellite data (ASTER,
Landsat-8, and Radarsat-2) by different remote sensing techniques. These techniques led to
good discrimination for lithological units, delineation of structural lineaments, which
controls the gold distribution and also highlighting the mineralized hydrothermal alteration
zones.
The study area comprises variably deformed dismembered ultramafic/mafic
ophiolitic sequences and island-arc volcanosedimentary and plutonic rocks. These rocks are
intruded by widespread syn- orogenic granitoids and separated intrusions of late- to postorogenic
gabbros and granites. Felsic and mafic dikes traverse all previous rocks with
several orientations. These rocks are intruded by Red Sea rift-related Tertiary basalt.
Quaternary sand sheets, sand dunes and wadi alluvium are covered the exposed rocks in
several places.
Measurements of structural features for mineralized quartz veins and alteration
zones are confirmed with photos and sketches. Moreover, comprehensive regional tectonic
and geological setting of the South Eastern Desert (SED) as a part of the Nubian shield and
its controls for gold mineralization are discussed. The SED is affected by four main events of
deformation; Allaqui – Heiani Suture (AHS; 750-720 Ma ago) early transpressional phase
(thrusts and folds), Onib–Sol Hamed Zone (OSHZ), Hamisana N-S trending Shear zone
(HSZ; 660-550 Ma ago) (East-West crustal shortening) and its splays and Hodein–Rahaba
(HRSZ) NW-trending sinistral strike slip shear/fault zone (Najd Fault system 630-550 Ma
ago). Romeit gold district is a NNE trend splay of Hamisana N- trend mega shear zone.
Fire assay data of gold for 340 quartz vein samples and 382 samples from
hydrothermally altered quartz diorite show the high potentiality of Romeit district beside
strong correlation of gold distribution with deformed zones.
Whole rock geochemistry (major oxides) has been done for hydrothermally altered
and unaltered quartz diorite using XRF method. The results show enrichment and depletion
for some oxides. Hydrothermal alteration processes at Romeit gold district are represented
by sericitization, cholritization, carbonization and silicification. These alterations are
characterize the orogenic gold deposits (Lode gold) worldwide. Moreover, the ICP-MS data
of selected trace elements from hydrothermally altered quartz diorite show the strong direct
correlation of gold with arsenic and zinc.
High potentiality of gold at Romeit district was confirmed by several tools; one of
them is study of recent alluvial deposits at Romeit drainage pattern. The angular shapes and
the considerable quantity of gold grains in the alluvial samples are strong evidence of gold
fertility of Romeit district.
In conclusion, the characteristics of Romeit gold district indicate that gold
mineralization is lode gold style, which is shear controlled and in turn the shear zones in the
Nubian shield should subjected to full detailed exploration programs.