URANIUM ORE DEPOSITS IN EGYPT

Lecture 5:
Hassan Z. Harraz
hharraz2006@yahoo.com
2016- 2017
@ Hassan Harraz 2017

Outline of Lecture 5:
 CATEGORIES OF URANIUM DEPOSITS
 URANIUM ORE MINERALS
 URANIUM DEPOSITS IN EGYPT
 Introduction
 Uranium Occurrence in the Egypt
 Types of Uranium Deposits in Egypt:
 Uranium Occurrences in Pan-African
Younger Granites of Egypt
 Uranium Occurrences in Dykes
 Uranium Occurrences in Sedimentary
Rock Sequences of Egypt
 Categories of Egyption Uranium Deposits:
I) Vein types:
1)Uranium deposits of Gabal Gattar
2)Uranium deposits of Gabal El-Missikat
3)Uranium deposits of El Erediya
4)Uranium deposits of Um Ara area
II) Volcanic type deposits:
5) Uranium deposits of El Atshan-II
III) Surficial deposits:
6) Uranium deposits in Sinai
7) Black Sand
IV) Phosphorite deposits
References
2

CATEGORIES OF URANIUM DEPOSITS
 Uranium deposits world-wide can be grouped into 13 major categories of deposit types
based on the geological setting of the deposits (OECD/NEA & IAEA, 2014):
1) Unconformity-related deposits (Canada, Australia) (39%)
2) Sandstone deposits (all over the word) (29%)
3) Metasomatite deposits (10%)
4) Hematitic Breccia complex deposits (only Australia – Olympic Dam) (9%)
5) Volcanic deposits(8%)
6) Paleoplacer (Quartz-pebble conglomerate) deposits (2%)
7) Intrusive deposits (Namibia) (1%)
8) Limestone deposits
9) Surficial deposits (USA, Australia, Canada and Namibia)
10) Vein type deposits (all over the word)
11) Phosphorite deposits
12) Lignite deposits (USA)
13) Black shale deposits
Australian uranium deposits can be grouped into 6 of these categories, with
some mineralisation in two further ones.
Most of Australia's uranium resources are in two kinds of orebodies,
unconformity-related and breccia complex, while sedimentary deposits are less
significant than overseas
 [percentages are production in 2014]
4

Carnotite
K2(UO2)2(VO4)2·3H2O,
An important “secondary”
uranium-vanadium bearing
mineral, from Happy Jack
Mine, White Canyon District,
Utah, USA. Credit: Andrew
Silver.Uraninite (Pitchblende) UO2
Autunite
a secondary uranium mineral named after the
town of Autun in France
Torbernite
an important secondary uranium mineral
Uranium Minerals
5

URANIUM ORE MINERALS
Uranium can be found in a large number of minerals.
X-ray diffraction and SEM are usually used to identify U minerals and the associated alteration
products.
The most common economic minerals are listed below:
1) Oxides:
 Uraninite (crystalline UO2-2.6)
 Pitchblende {an amorphous, poorly crystalline mix of uranium oxides often including
triuranium octoxide (U3O8) (amorphous UO2-2.6)} , though a range of other uranium minerals
is found in particular deposits.
 Carnotite K2(UO2)2(VO4)2• 1–3 H2O
 Brannerite: (U,Ca,Y,Ce)(Ti,Fe)2O6
2) Silicates: Hydrated uranium silicates:
 Uranophane (CaO, 2UO2 , 2SiO2, 6H2O)
 Coffinite (U(SiO4)1-x(OH)4x)
3) Phosphates-Hydrated uranium phosphates of the phosphuranylite type; including:
 Autunite Ca(UO2)2 (PO4)2 • 10H2O
 Saleeite Mg(UO2)2(PO4)2•10H2O
 Torbernite Cu(UO2)2(PO4)2 • 12H2O
4) Organic complexes & other forms
 The “primary” uranium minerals weather and break down very easily when exposed to water
and oxygen, to produce numerous “secondary” (oxidized) minerals, for example carnotite
and autunite, which are often mined, but in significantly lower quantities that uraninite.
 Uranium is also found in small amounts in other minerals:
allanite, xenotime, monazite, zircon, apatite and sphene. 6

Introduction
Uranium - Thorium Exploration activity started in Egypt as early
as 1956.
Geophysical, radiometric and geologic exploration resulted in
the discovery of many radioactive anomalies sporadically
distributed in different geologic environments in different parts of
the country especially in the Red Sea Hills, but occasionally on
the younger sedimentary cover in the northern part of the
Western Desert, Eastern Desert, and Central Sinai.
8

Uranium Occurrence in the Egypt
 Western Desert: uranium in sedimentary host rocks of
different ages (Carboniferous, Oligocene) in Gabal
Qatrani, Gabal Hafhuf (Bahariya Oases), Sitra Lake, as well
as in Sabkha.
 Eastern Desert: vein-type uranium associated with Post-
Orogenic granitic magmatism of Pan-African age at Wadi
Araba, EI-Maghrabiya (El Erediya and El Missikat), Um Ara,
Nugrus area, and Gabal Gattar. Felsites and Bostonite
dyes at El Atshan area.
 Sinai Peninsula: uranium mineralization in a karst
environment in Carboniferous dolomites at Abu Zeneima.
The above occurrences have been investigated by surface
methods, including topographic, geologic and radiometric
mapping, as well as by some trenching and tunneling.
Most of Egyptian uranium occurrences containing low grade
uranium ores which can extracted by heap leaching techniques.
9

Location map showing
the uranium
occurrences in Egypt
10

TYPES OF URANIUM DEPOSITS IN EGYPT
The uranium-bearing deposits of Egypt can be described as follows:
1) In Younger Granites (e.g., Gabal Gattar, El-Missikat, El Erediya,
Gabal Kab Ameri, Gabal Um Ara).
2) In Dyke of Felsites and Bostonites (e.g., El Atshan area).
3) In Shales, Sandstones, and the Carbonaceous Sediments
(e.g., Wadi Araba, Um Bogma, Um Kharit, Gabal Qatrani,
Bahariya oases)
4) In Phosphate Deposits (e.g., Abu Tartour, Hamarwain, Mahamid).
5) In Black Sands (in the Mediterranean coast of Egypt from Rashid to
Rafah city).
6) In Sabkha deposits (e.g., in Sitra, Nuweirnicya, Bahrein and El
Arag lakes in the Western Desert).
7) In Siltstone of Hammamat deposits (e.g., Um Tawat, Wadi EI-
Kareim).
 Most of these works were concentrated on the Eastern Desert terrains,
particularly in granitic rocks. Main discoveries are four uranium
occurrences in Pan-African Younger Granites, besides one at the
contact of bostonites and felsite dykes in metasediments and one in
pasamitic gneisses in the Eastern Desert, as well as one in siltstone
in a Paleozoic sedimentary basin within granitic rocks in Sinai.
11

Uranium resources in Egypt may be classified as:
1) Vein-type (G. Gattar ; G. El-Missikat; G. El Sella; and Abu
Rusheid Area);
2) Volcanic-type (El Atshan area).
3) Surfacial type U-deposit in sedimentary rocks (Abu
Zeneima);
4) Phosphorite deposits
12

1) Uranium Occurrences in Pan-African Younger Granites
(YG) of Egypt
 Uranium - Thorium Exploration activities led to the discovery of several uranium anomalies and occurrences,
especially in the Younger Granites (YG) as vein-type uranium associated with Post-Orogenic granitic magmatism of
Pan-African age at Wadi Araba, EI-Maghrabiya (El Erediya and El Missikat), Um Ara, Nugrus area, and Gabal Gattar.
 In almost all of these occurrences, the U-mineralization is structurally controlled with preferable development at the
marginal zones of the enclosing granites or associated with wide scale alteration features. But, the question is
why some Egyptian younger granitic masses do not show any valuable U-anomalies, in spite of the
presence of fracturing and large scale alteration.
 Thus, not only secondary processes (as fracturing or alteration) but also the magmatic processes may represent
the main factors controlling U-distribution. In other words, the composition of magma may introduce U-poor or U-
rich granites. Alteration and fracturing of U-rich granites help meteoric water and hydrothermal solutions to liberate
labile uranium and precipitate their loads along microfractures, joints and fault planes.
 The uranium mineralization related to granite masses, where it occurs either as disseminations in the
autometasomatically altered parts (greisens and albitites), or where it forms veinlets and stringers across
granite masses (Hussein et al., 1986).
 Several plutons of these Younger Granites in the Eastern Desert, host a variety of rare metal mineralization
including uranium.
i) The Gattar granite pluton, at the northern-part on the Eastern Desert, hosts vein-type uranium
mineralization associated with molybdenite.
ii) Two Younger Granite plutons: namely El Missikat and El Erediya (El Maghrabiya area), in the central
part of the Eastern Desert, host siliceous vein-type uranium mineralization, which is structurally controlled
by faults and their leather joints associated with NE and NNE trending shear zones.
iii) At the Gabal Kab Ameri, in the central part of the Eastern Desert.
iv) At the southern part of the Eastern Desert, Um Ara granite hosts uranium as disseminated unconformity
contact type.
 The estimation of the uranium potentiality of the four younger granite plutons is 14000 tons uranium as speculative
resources.
13

Uranium Ore Minerals in YG
 Granitic rocks which is the most predominant-type comprising the Pan-African is found to be the
most favorable host of radioactive anomalies, some of these anomalies are found to be either
uranium-bearing or thorium-bearing depending upon the predominance of uranium or thorium
minerals.
 The most ubiquitous radioactive minerals include
 Uraninite (crystalline UO2-2.6);
 Pitchblende (amorphous UO2-2.6),
 Uranothorite {(Th,U)SiO4},
 Thorite {Th(SiO4)},
 Thorianite (ThO2),
 Xenotime {Y(PO4)},
 Monazite {Ce0.5La0.25Nd0.2Th0.05(PO4)},
 Zircon
 and a suite of secondary uranium minerals, the most common of which are
 Uranophane (CaO. 2UO2 . 2SiO2 . 6H2O),
 Autunite {Ca(UO2)2 (PO4)2 • 10H2O},
 Soddyite {(UO2)2(SiO4)•2(H2O)},
 Clarkeite {Na0.7Pb0.1Ca0.1(UO2)0.9O0.9(OH)1.1•0.1(H2O)})
15

2) Uranium Occurrences in Dykes
 Another favorable geologic environment for uranium is delineated in the central part
of the Eastern Desert where the host rock is alkaline sills and dikes of trachytic
composition (Bostonites).
 Uranium is epiqenized in the form of El Atshan area (probably amorphous
Clarkeite {Na0.7Pb0.1Ca0.1(UO2)0.9O0.9(OH)1.1•0.1(H2O)} and secondary alteration
minerals particularly along joint planes and along contact with the enclosing
metasedimentary rocks. Although this type of occurrence is repeated in several
places, it represents only small-sized prospects of subeconomic potential.
16

3) Uranium Occurrences in Sedimentary Rock Sequences of
Egypt
 Radioactive anomalies discovered in the Younger Sedimentary cover are represented by
anomalies in Carboniferous rocks, in Cretaceous rocks, in Oligocène rocks and in
Recent deposits.
a) In Carboniferous rocks (part of Um Bogma Formation), Uranium anomalies are
restricted to Central Sinai and its economic potentiality is not yet assessed.
Uranium mineralization is also delineated in a karst environment in Carboniferous dolomites
(i.e., Surfacial type U-deposit in sedimentary rocks) at Abu Zeneima.
b) Anomalies in Cretaceous black shales, and in phosphorite deposits. Cretaceous rocks
are related to the exposed section containing phosphates and phosphatic rocks
occurring along the Red Sea (between Quseir and Safaga), along the River Nile
(between Idfu and Qena) and in the Western Desert (Oases).
 Phosphates and phosphatic rocks represent a substantial uranium
resource in Egypt.
c) Anomalies in Oligocene Shales and Sandstones are restricted to the northern part of
the Western Desert. The economic potentiality of this type depends largely on the
development of appropriate flowsheet for extraction of uranium particularly, if we kept
in mind that there is no other by-product that will come out with uranium.
 It was also discovered in the Oligocene sandstones and associated rocks at
Gabal Qatrani, where uranium of up to 0.3% U3O8, is concentrated in the
intersitital spaces between sand grains (Said, 1962).
d) The Recent deposits are represented by the vast resource of Black Sands containing
monazites spreading over along the Mediterranean coast. The economic potentiality of
this commodity is viewed in terms of appropriate marketing of the different products
coming out of this sand (rutile, zircon, ilmenite, magnetite, ... etc), and the
industrialization of large tonnage of monazite-rich concentrate.
17

Categories of Egyptian Uranium Deposits
In the following some lights will be given to the
areas with more potentialities in Egypt.
Based on the geological setting of the deposits (OECD/NEA & IAEA, 2014), Egyptian uranium
mineralization can categorist as following::
I) Vein types
1) Uranium deposits of Gabal Gattar
2) Uranium deposits of Gabal El-Missikat
3) Uranium deposits of El Erediya
4) Uranium deposits of Um Ara area
II) Volcanic type deposits
III) Surficial deposits
7) Black Sand
IV) Phosphorite deposits
18

 Gabal Gattar area, at the northern-part on the Eastern Desert, is bounded by the following coordinates:
longitudes 33° 13/ 26// - 33° 25/ 47// E and latitudes 27° 02/ 00// - 27° 08/ 30// N.
 The early studies which had been carried out before 1984 were mainly dealt with the geology,
petrography, geochronology and geochemistry of the normal Gattarian granites as well as the mining
prospection for molybdenum deposit. After discovering U-mineralization in Gabal Gattar granites (northern
part of the Gattarian granite batholith) by NMA during the field season 1984/1985.
 Gabal Gattar area, as a segment of the north Eastern Desert of Egypt, is a part of the Arabian-Nubian
shield.
 This area is dominantly covered with Pan-African rocks, mainly Younger Granites of late Proterozoic
age. The Gattarian granite mass forms an elongated huge granite batholith trending by its long dimension
(40 km) in a NS direction. More than 80 publications and internal reports had been carried out on this
granite mass.
 The Gattar granite pluton hosts vein-type uranium mineralization associated with molybdenite.
 The Younger Granites of Gabal Gattar acquire their importance from hosting of uranium mineralization
in eight uraniferous occurrences namely G-l, G-ll to G-VIII.
 They are characterized by visible intense secondary U-minerals with their characteristic yellow to greenish
yellow colours.
 Only one occurrences (G-V) was confined to a strongly altered contact zone between the northern
border of Gabal Gattar granite and the closely adjacent Hammamat sediments of Gabal Um Tawat along
Wadi Bali. The locations and distributions of the recorded uraniferous sectors are structurally controlled by
the NNE, NS and ENE major fracture systems and shear zones (i.e., Unconformity-related deposit
Types).
 Nearly all the recorded U-mineralized sectors are found to be associated with strongly deformed and
deeply hematitized granite zones. Only one occurrence (G-V) was confined to a strongly altered contact
zone between the northern border of Gabal Gattar granite and the closely adjacent Hammamat sediments
of Gabal Um Tawat along W. Bali. The locations and distributions of the recorded uraniferous major
fracture systems sectors are structurally controlled and shear zones.
 G-l, G-II, G-V and G-VI represent the most significant and more promising uraniferous occurrences. The
visible secondary U-minerals are encountered filling large and feather fractures with thickness ranging
from a few mm to a~8 mm. They are always accompanied with deep brown hematite and occasionally
with dark violet fluorite.
19

Mineralogy
 Radiometrically, the normal granites forming Gabal Gattar are considered as an uraniferous granite type, its
specific background gamma activity range is normally exceeding than that of the normal world granites (4 ppm U
and 14 ppm Th). It has U-contents ranging from 12 to 30 ppm with an average value of 18 ppm, whereas their Th-
contents are within the normal value (15 ppm).
 The main U-minerals in Gabal Gattar U-prospect identified are given below.
 These U-minerals are occasionally associated with calcite, fluorite, hematite, and ilmenite. Biotite, zircon,
wolfenite, and chlorite. Some of these gangue minerals, especially hematite and ilmenite, play an important role in
fixation of U-minerals from its beating circulating water. Minerals Formulae
Uraninite 2UO2
Carnotite K2O, 2UO2, 2VO4
Umohoite UO2, MoO4, 4H2O
BeCquerelite 7UO3, H2O
Masuyite UO3. H2O
Uranophane CaO, 2UO2 , 2SiO2, 6H2O
-Uranophane CaO, 2UO2, 2SiO2. 6H2O
Kasolite Pb, 2UO2, 2SiO2, 2H2O
Zippeite 2UO3, 2SiO2. 2H2O
Soddyite 3UO2, 2SiO4, OH, 5H2O
 The encountered U-minerals are usually associated
with dark brown hematite and occasionally with deep
violet fluorite.
 Fluorite is sometimes recorded without my trace of U-
minerals indicating presence of two generations of
fluorite.
 Primary U-minerals (uraninite) are occasionally
identified in some intensely uraniferous parts.
22

Characterization of uranium deposits in Gabal Gattar:-
 U and Th are concentrated mainly in the accessory minerals; more than 80 % of U is contained in accessory
minerals while only a maximum of 20 % U is associated with essential minerals. The secondary minerals (as
hematite, fluorite and clay minerals), which formed during post magmatic processes, concentrate much more U
than Th indicating that U enrichment is controlled mainly by post magmatic processes to a great extent.
 The highest U and Th contents are displayed by hematitized granite. Thus, a positive correlation between the
degree of hematitization and the intensity of uranium mineralization. This feature supports the hydrothermal
concept of mineralization at Gabal Gattar uranium prospect. The probable source of uranium bearing fluids
could originate be either from the granite at its late or post magmatic stage or from some deeper source
(Roz, 1994).
 The presence of quartz veinlets and deep violet fluorite in the mineralized granites is a supporting evidence for
hydrothermal vein type uranium mineralization (Salman et al., 1990 and Shalaby, 1995).
 The hypogene enrichment in uranium in the G-l occurrence is mostly due to hydrothermal solutions rich with
uranium which affected the Gattar granite and resulted in their intense alteration and deposited their uranium in the
structural network of the rocks. A supergene source of enrichment in uranium is mainly due to the leaching of
some of the magmatic uranium from the host rocks by meteoric fluids that were drained to the fractured and
sheared zones, where they deposited their loads (Moharem, 1997).
 Gattar granite was affected by strong acidic changed later to strong alkaline hydrothermal solutions. These
solutions played the most important role in the alteration of Gattar granite along shear zones. Acidic solutions with
low U, Th and Zr contents resulted in kaolinization of Gattar granite along shear zone. The acidic solutions were
changed to alkaline solutions rich in Fe, Th and U. In hematitized granite, U and Th replaced Zr especially along
zircon rims while iron oxides adsorbed most U and precipitated along fractures or coated the metamicted zircon
crystals (Dardier, 2000).
 Structurally, The Gattarian granite batholith was subjected to more than one tectonic episode printed on the rock
surfaces, by joints, faults and shear zones of various attitudes and directions. The NNE, NS, NE and ENE
directions represent the most significant fracture systems and shear zones. Along these fractures, granites are
highly sheared and extensively subjected to various deuteric and post magmatic hydrothermal alterations.
Hematitization silicification, kaolinization and epidotization are the most pronounced alteration features
encountered Fluoritization, episyenitization and carbonatization are superimposed later. Among these
alteration features, the hematitization, episyenitization of the granites and fluoritization are the most
significant ones, since they are oftenly associated with most of the recorded U-mineralized sectors.
23

Origin of uranium mineralization in Gabal Gattar:-
 Shalaby and Moharem (2001) suggested that the geochemical behavior of U and the genesis of U deposits in the G-V occurrence
could have proceeded through the following successive stages:
(1) Uranium was first mainly trapped in the crystal lattice of accessory minerals of the granites.
(2) The area was affected by tectonic events producing faults and shear zones which acted as good channels for the
hydrothermal ascending fluids and the percolating meteoric water to mix with the trapped residual magmatic fluids rich in U
and Th, and generating a low temperature hydrothermal system. This released U from the essential and accessory minerals
of the hosting granites and redeposited it as uranium minerals in the shear zones. , and
(3) The supergene meteoric water and super-heated solutions could pass through the structural network. They leached some
of the magmatic U from the younger granites and reprecipitated their loads, in the shear and weak zones of the Hammamat
sediments, by the effect of evaporation and adsorption on the surface of Fe oxides and clay minerals.
 The hydrothermal concept could be accepted for the local uranium mineralizations in the shear zone, but the surfacial enrichment
of secondary uranium could, however, be considered as due to the oxidation and mobilization of uranium and the adsorption of its
minerals on the surface of clay minerals and iron oxides in granites.
 Therefore, magmatic differentiation plays a small part in uranium enrichment but secondary processes played the principal role in
the uranium enrichment of the mineralized granites, as following:
1)The fresh granite of Gabal Gattar could be classified as uraniferous granites. They are highly affected by faulting, jointing
and fracturing due to the active role of the various tectonic movements.
2)The planes of such structure provided easy channels for the passage of solutions.
3)These solutions affected the granites and resulted in their intense alteration. The types of alteration processes affect the
uranium concentration and its redistribution.
4)The U-bearing solutions may be of hypogene origin and ascending through the structural network of fractures, and joints
which form suitable structural traps for mineralization.,
5)The secondary source of uranium enrichment is the supergene fluids which percolate on the granite, and could leach some
of their magmatic uranium.
6)The role of iron oxides in adsorbing uranium from its circulating solutions could not be neglected, and
7)The ascending alkaline hydrothermal solutions which caused hematitization are responsible for the U-mineralization along
shear zones of Gattar pluton. Thus, U-concentrations must probably increase with depth and the future subsurface works
may explore primary U-mineralizations of economic potentialities.
24

2) Uranium deposits of Gabal El-Missikat
 The granitic rocks of Gabal El-Missikat pluton are essentially composed of potash feldspars,
plagioclase and quartz, with subordinate biotite. Zircon, sphene, apatite and magnetite are
present as accessory minerals .
 These anomalies occur as disconnected lensoidal shapes with limited dimensions, where all
these anomalies are structurally controlled.
 It connected with jasperoid silica and strong alteration represented by silicification,
sericitization, hematitization and kaolinization.
 The uranium mineralization is mainly associated with smoky and/or red jasperoid siliceous
materials in reactivated shear fractures (M-I, M-II and M-III) crossing the orthoclase granites
in NE-SW to ENE-WSW directions and dipping steeply toward SE.
 Uranium mineralization are elongated generally in the direction of the main fracture zone and
occur along micro-fracture surfaces, and coating cavities and vugs as thin films and fine
clots.
 U-minerals are always found in association with black fluorite, and iron oxides and
manganese oxides.
 The uranium mineralization at Gabal El-Missikat occurrences is represented essentially by
visible secondary uranium minerals : uranophane and soddyite with finely disseminated
sooty pitchblende. Some of these anomalies are associated with lemon yellow secondary
uranium minerals (probably uranophane) and fluorite with deep violet -to black-colour.
 They are accompanied with sulphide and gangue minerals. Sulphides are mainly: pyrite,
calcopyrite, galena, sphalerite and molybdenite.
 The gangues are mainly iron and manganese oxides and fluorite.
 It belongs to the vein-type uranium deposits (Hussein et al., 1986) and relates to poly-
metallic vein type probably formed in reducing condition (Abu-Deif et al., 1997).
25

Figure 1: Geological map of El Erediya area (after Abu-Deif,1992)
29

3) Uranium deposits of El Erediya
Fig.5. The main shear zones in El Erediya granite.
 Uranium mineralization in El Erediya area, Egyptian Eastern Desert, is associated
with the hydrothermally altered parts of the granitic rocks, and localized within
several shear and fractured zones that are filled with jasperoid veins.
 This granite exhibits extensive alteration, including silicification, argillization,
sericitization, chloritization, carbonatization, and hematization.
 Alteration, such as hematitization, limonitization, and manganese stains, is
common.
 Mineralization is structurally controlled and is associated with jasperoid veins that
are hosted by a granitic pluton.
 The primary uranium mineral is pitchblende, whereas uranpyrochlore,
uranophane, kasolite, and an unidentified hydrated uranium niobate mineral are
the most abundant secondary uranium minerals.
 The mineralization is associated with red jasper, black and grey amorphous silica,
chalcedony and quartz.
 Gangue minerals are represented by quartz, carbonate and fluorite.
30

A two-stage metallogenetic model (after Abd El-Naby, 2008) is proposed for
the alteration processes and uranium mineralization in El Erediya area. The
primary uranium minerals were formed during the first stage of the
hydrothermal activity that formed jasperoid veins in the El Eradiya granite
(130–160 Ma). This stage is related to the Late Jurassic–Early Cretaceous
phase of the final Pan-African tectono-thermal event in Egypt. After the
formation of El Erediya jasperoid veins, they were subjected to a late stage of
hydrothermal alteration encompassing argillization, dissolution of iron-
bearing sulfide minerals, formation of iron-oxy hydroxides, and corrosion of
primary uranium minerals. Fluids altering the early formed minerals, such as
petscheckite to uranpyrochlore and oxy-petscheckite, were enriched in U, Ca,
Pb, Zr, and Si.
Uranium was likely transported as a uranyl carbonate and uranyl fluoride
complexes. In the nearsurface environment, these complexes became
unstable and decomposed in the presence of silica, calcium, and lead to form
uranophane and kasolite. Iron and manganese oxides played a role in
extraction and fixation of uranium from solution.
Finally, oxy-petscheckite was subjected to a later stage of low-temperature
supergene alteration and altered to an unidentified hydrated uranium niobate
mineral by removal of Fe.
Metallogenetic Model
31

Fig. 4 Genetic model for uranium minerals and associated alteration in the El Erediya granite (after Abd El-
Naby, 2008).
32

4) Uranium deposits of Um Ara areaUm Ara area bounded between latitudes 22° 30/and 22° 42/ N and longitude 33° 45/ and 33° 55/ E.
The younger granitic pluton covers 30 km2 in the central part. It is intruded into a tectonic mélange to
the southeast, south and west. The mélange comprises metasedimentary matrix with the serpentinites
making up the rock fragments and blocks. The younger granites are faulted against the arc
metavolcanics to the northern and faulted against the younger Dokhan volcanics to the north.
Um Ara granitic pluton was affected by faults having various trends. The major faults trend in the E-W,
N-S, ENE, ESE, NE and NW directions. The earlier E-W faults are sinistral faults with oblique slip. The N-
S and ENE trending faults form conjugate set indicating crustal shortening in NE direction and
extension in the NW one. The later NW-faults are analogous to the NW-wrench faults of the Najd Fault
System in Saudi Arabia and described in the Central Eastern Desert of Egypt by Stem (1985).
Um Ara granite pluton comprises three main rock varieties:
a) Coarse grained monzogranitic phase covering about 90% of the pluton area.
b) Fine grained alkali feldspar granitic phase covering the northern western corner. The fine-grained
phase is intruded into earlier monzogranites and exhibits the effects of intense mechanical
deformation and shearing.
c) Upper zinnwaldite albitized granite zone. The rock is fine grained, alkali feldspar granites and
showing different of red, pink, buff, green and yellow colours. They are essentially composed of
quartz, K-feldspars and plagioclases. Biotite, phlogopite, muscovite and lepidolite are the main
varieties. In most cases, the micas are of secondary origin where they fill mariolitic vugs replacing
the felsic components. The accessory minerals are mainly fluorite, zircon, garnet and secondary
uranium minerals.
33

Figure 1. Geological map of the Um Ara area, south Eastern Desert of Egypt (after Abd El-Naby, 2008).
34

4) Uranium deposits of Um Ara area
U mineralization
 Radioactive mineralizations in Um Ara -Um Shilman younger granite pluton are restricted to the
medium grained variety which range in composition from albitized to the potash feldspar-rich
granites.
 The uranium mineralization of Um Ara are structurally controlled following WNW and NW trends .
 Uraninite and/or thorite inclusion in orthoclase, plagioclase feldspars, quartz and biotite which
points out to their syngenetic origin.
 Later alteration caused their oxidation to a group of secondary minerals
 Secondary U mineralization is found in the oxidized zone pervading fractured albitized
and alkali-feldspar granites emplaced at the northern boundary of Um Ara Pluton.
 It occurs as stains along crevices and fracture surfaces and as idiomorphic and acicular
crystals filling cavities.
 U-mineralization is dominated by Uranophane and -Uranophane and traces of Uraninite,
topaz, monazite, zircon, apatite, rutile, Deep violet fluorite, Ca-montmorillonite and illite .
 The wall rock alteration comprises silicification, microclinization, albitization and hematitization.
 The association of topaz and monazite with Li-rich mica indicates the enrichment of
the late stage hydrothermal fluids in F and P (London, 1987).
 Uranpohane and -uranophane are the most abundant U minerals, whereas Ca-
montmorillonite and illite represent low temperature alteration products of the host
granitic rocks.
Origin
 The genesis of secondary U minerals is mainly attributed to the action of oxic
groundwater on previously corroded primary U minerals. These secondary U minerals
were deposited near the surface from the circulating groundwater by evaporation.
35

 El Atshan area is covered by different Pan-African rocks, which intruded by younger
bostonite rock, andesite dykes and carbonate veins.
 El Atshan mining area, central Eastern Desert, represents one of the uranium
occurrences related to alkaline volcanic rocks in n Egypt.
 This mining area seems to have been subjected to the influences of groundwater
activity, the underground levels of this mine are currently submerged with water. So, this
mine could be regarded as a good example for investigating the role of aqueous fluids in
the redistribution of uranium.
 El Atshan-II uranium prospect area which lies at the intersection of about 25˚50'35“N
and 34˚06'35"E., on the Red Sea Coast (Fig.1a), represents one of the important
anomalously high radioactivity areas and is becoming a promising target for U
exploration.
 The radioactive anomalies, with or without visible U mineralization, are mainly restricted
within and around joints and fractures in the bostonite rock and sporadically along its
upper and lower contacts with the older country rocks.
 The bostonite is a Post-orogenic volcanic rock, widely distributed in the central Eastern
Desert of Egypt and occurs mainly in the form of dykes and sills with length and
thickness of about 0.5 - 1.5 km and 3 - 20 m, respectively.
 This volcanic rock is present in more than one generations where the Rb-Sr age ranges
from 302 to 245 Ma, corresponding to Carboniferous to Early Permian age {74 Ma;
Mahdy et al., 1994).
 From the mineralogical point of view, bostonite represents one of the most important
igneous rocks which host U and/or thorium (Th) minerals, and it can be divided into U-
rich and Th-rich bostonite (Mahdy et al., 1994).
36

Geologic map of El Atshan mining area (after Dawood et al., 2004)
37

Figure 1. Location and geologic maps of El Atshan-II uranium prospect area, central Eastern
Desert, Egypt.
38

Fig.3. Forms of the ordebodies in Wadi El
Atshan locality (after Sayyah and El
Shatoury, 1991).
 Lenses of uranium concentration in the form of disseminated pitchblende were
located (Obrenovich et al., 1965) (Fig. 3).
 Both hypogene and supergene processes played an important role in the genesis of
uranium mineralization in the Al Atshan area.
 The hypogene process is evidenced by the presence of primary uranium mineralization
of siliceous U-sulfides type, whereas the supergene process is indicated by the alteration
of feldspars and the formation of secondary minerals such as kasolite and soddyite on
the fracture surfaces. The secondary minerals are represented by quartz and calcite in
the form of thin veinlets or fracture fillings. Similarly, the foliated siltstone beds are altered
along their contacts, faults and fractures.
 It is apparent that the bostonite was undergoing a long period of alteration and rock–fluid
interaction, providing the source for the formation of the secondary uranium minerals on
the surface.
39

Genetic model (after Dawood et al., 2004)
El Atshan mining area, central Eastern Desert, represents one of the
uranium occurrences related to alkaline volcanic rocks in Egypt. Based on
the plot of total alkali elements versus silica, these rocks are classified as
trachytes. The U and Eu anomalies appear to be derived from trachyte
exposed to a long period of alteration and rock–fluid interaction. The
trachyte has been subjected to two phases of alteration. The pronounced
chemical changes include the mobility of Si, Na, Fe, U, Zn and REE and
the immobility of Mg, Th, Hf, Ta and Sc. The late stage hydrothermal
solutions caused the breakdown of the feldspars by losing sodium,
potassium and partially silica and eventually formation of argillic alteration
products, dissolution of iron-bearing sulphides, formation of iron-oxy
hydroxides and corrosion of primary uranium minerals forming uranyl oxide
hydrates. The acidic water percolating through the fractured trachyte rock
leached not only available major or trace elements, but also REE.
Eu originally incorporated in feldspars as Eu+2 has been oxidized to Eu+3
and subsequently leached away leaving a negative anomaly in the host
rock. The leached U and Eu were then transported most probably as
carbonate complexes. The second phase of alteration occurred at the near
surface profile when the late stage hydrothermal fluids cool to the
temperature of meteoric water and may have mixed with it, the pH of the
fluids would shift to more alkaline values and at these conditions U and Eu
were precipitated into the fracture system mainly by being adsorbed on the
clay minerals and probably coprecipitated with iron oxy-hydroxides.
40

Genetic model for genesis of U and Eu anomalies in El Atshan mining area
(after Dawood et al., 2004)
41

Trace amounts of uranium are known to be associated with
carbonaceous Jurassic sedimentary rocks in the Maghara
area of the Platform Province and with manganese are
deposits east of Abu Zenima and Abu Rudeis. Due to its
classified nature, information regarding uranium
mineralization elsewhere in Sinai and in Egypt's Eastern
and Western Deserts could not be obtained. Consequently,
Dames & Moore must rely on its assessment of favorable
host environments in Sinai to evaluate the potential for
economic uranium occurrences.
Our review of literature for the post-Carboniferous
sandstone deposits of north Sinai did not detect the
potential presence of pronounced oxidation/reduction fronts.
These serve as the concentrating mechanism for roll-front
uranium mineralization such as that which occurs in the
western United States. Furthermore, extensive sequences
of acid extrusive volcanic tuffs or detritus from acid intrusive
rocks--indicative of trace amounts of uranium--are not
present; therefore, we assess the potential for large
uraniferous sandstone deposits in Sinai as limited. This
does not preclude the occurrence of small concentrations of
uranium in sandstone in close association with igneous
intrusive and high-grade metamorphic rocks, particularly in
the vicinity of manganese-iron mineralization.
42

 Uranium content in
phosphoric acid is proportional
to its content in the phosphate
ore. However, Concentrations
above 80 ppm U, is viable as
commercial by-product.
 It is important to note that
removal of uranium from
phosphoric acid is an
environmental commitment.
Histogram shows distribution of uranium in some
Egyptian phosphorites
Uranium Extracted from Egyptian Phosphorite Deposits
43

The average uranium content of various phosphatic rocks in Egypt
Area Locality U (ppm) Reference
Red Sea
Quseir
85 Davidson & Atkin (1953)
67 Abdou (2002)
Um El-Hweitat 49 Shahata et al (2004)
Wasif 84 Shahata (2005)
Safaga
102 Davidson &Atkin (1953)
131 Abdou (2002)
Hamrawin
94 Hassan & El-Kammar (1975)
55.2 Abdou (2002)
Abu Shegiala 35 Ahmed (1986)
Nile Valley
Oweinia 143 Hassan& El-Kammar (1975)
Mahamid East
98 Germann et al (1987)
116.5 Abdou (2002)
Mahamid West
67 Hassan & El-Kammar (1975)
62.6 Abdou (2002)
Sibaiya East 94 Hussein (1954)
East Luxor 114 Salman (1974)
Wadi Higaza 69 El-Aassy (1977)
Western Desert
Kharga Oasis
20 Zaghloul & Abdel Aziz(1961)
32 Zaghloul & Mabrouk (1964)
Abu Tartur
20 El-Mahrooky (1992)
33 El-Kammar&El-Reedy (1984)
24.7 Abdou (2002)
Sinai
East El Qaa
SouthWeast Sinai
88 El-Aassy (1992)
38 Shahata et al (2001)
44

Locality
phosphorites
(million tons )
P2O5-content
(million tons )
U-content
(Tons)
Red Sea 72 16.7 7,000
Nile Valley 225 55.8 22,500
Western Desert 700 156 21,000
The phosphate resources and uranium content in the different localities of phosphatic rocks
in Egypt
 There are no good figures on the current production of phosphate rock
in Egypt. In 1977 There was a reported production of 600,000 tons of
phosphate.
 The total uranium content would be 120,000 pounds (60 ton) per year,
assuming uranium content 100 ppm. The phosphate resources and
uranium content according to De voto and stevens (1979) are tabulated
in table (2)
45

SourcesInternational Atomic Energy Agency (IAEA)
Uranium Minerals
Uranium Deposits
Abdalla, H.M., 1996. Geochemical and mineralogical studies at Um Ara rare metals prospect, Southeastern Desert, Egypt. Ph.D. Thesis, Hokkaido University, Sapporo,
Japan.
Abdel Meguid, A.A., 1986. Geologic and radiometric studies of uraniferous granite in Um Ara–Um Shilman area, south Eastern Desert, Egypt. Ph.D. Thesis, Suez Canal
University, Egypt.
Abdel Monem AA, Bakhit FS, Ali MM (1990) Trace and rare earth elements geochemistry of the uranium mineralization at El Erediya, central Eastern Desert, Egypt. J
Egypt Mineral 2:143–150
Abd El-Naby, H.H. (2008). Genesis of secondary uranium minerals associated with jasperoid veins, El Erediya area, Eastern Desert, Egypt Miner Deposita 43, 933–944.
DOI 10.1007/s00126-007-0171-1
Abu-Deif A (1985) Geology of uranium mineralization in El Missikat area, Qena-Safaga road, Eastern Desert, Egypt. Unpublished M.Sc. thesis, Al-Azhar University, 103 p
Abu-Deif A (1992) The relation between the uranium mineralization and tectonics in some Pan-African granites, West of Safaga, Eastern Desert, Egypt. Unpublished
Ph.D. thesis, Assiut University, 216 p
Abu-Deif A, Abouelnaga HS, Hassanein HI (2001) Distribution of radioelements and its relation to uranium migration, El Erediya exploratory tunnels, central Eastern
Desert, Egypt. J King Abdulaziz Univ (Earth Sci) 13:19–40
Abu-Deif, A., Ammar, S.E. and Mohamed, N.A. (1997) Geological and Geochemical Studies of Black Silica at El-Missikat Pluton, Central Eastern Desert, Egypt, Proc.
Egypt. Acad. Sci. 47, pp: 335-346.
Dawood, Y.H. ; Abd El-Naby, H.H.; and Sharafeldin, A.A. (2004). Influence of the alteration processes on the origin of uranium and europium anomalies in trachyte,
central Eastern Desert, Egypt. Journal of Geochemical Exploration 88, 15–27
Dawood, Y.H., Abd El-Naby, H.H., 2001. Mineralogy and genesis of secondary uranium mineralization, Um Ara area, south Eastern Desert, Egypt. J. Afric. Earth Sci. 32
(2), 317–323.
El Ghawaby; Salman, A.B.; and El Amin, H. (1963). On results of drilling at uranium occurrences of Al Atshan locality, central Eastern Desert, Egypt: Internal Report,
Geology and Nuclear Raw Materials Dept., AEE, Cairo 25p.
Hussein, A.H.; Hassan, M.A.; El Taker, M.A; and Abou Deif, A. (1986). Uranium bearing silicious veins in younger granites, Eastern Desert, Egypt, IAEA-TECDOC-361,
Vienna 143-157.
Ibrahim, M.E., 1986. Geologic and radiometric studies on Um Ara gramte pluton, South East Aswan, Egypt. M.Sc. thesis, Mansoura University, 177p.
Mahdy, M.A., Salman, A.B. and Assaf, H.S. (1994) Bostonite Rocks as Additional Uranium Resources in Egypt. Second International Conference of the Geology of the
Arab World, Cairo University, Egypt, 77-96.
Obrenovich, M.; EL Kassas, I.; and El Amin, H. (1965). Report on the results of detailed exploratory mining works at the uranium deposits in Wadi Al Atshan locality,
central Eastern Desert, Egypt: Internal Report, Geology and Nuclear Raw Materials Dept., AEE, Cairo 31p.
Salman, A.B., El Aassy, I.E., Shalaby, M.H. (1990). New occurrence of uranium mineralization in Gabal Qattar, Northern Eastern Desert, Egypt: Annals of the Geol. Surv.
Egypt, V. XVI (1986-1989) 31-34.
Sayyah, T.A. and El Shatoury, H.M. (1991). Uranium Resources and Reserves in Egypt. Assessment of Uranium Resources and Supply-IAEA, VIENNA, IAEA-TECDOC-597,
51-68. ISSN 1011-4289
46

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47

Regional
geologic map for
Wadi El Kareem
Area, ED, Egypt
48

El- Sella shear zone (ENE–WSW) cuts two mica granites,
Eastern Desert, Egypt.
49

Geologic map of W. Sikait, South Eastern Desert,
Egypt
56

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