1. INTERNATIONAL ATOMIC ENERGY AGENCY
Technical Meeting on The Origin of Sandstone Uranium
Deposits: A Global Perspective
29 May – 1 June 2012, Vienna, Austria
Uranium mineralization hosted by the
Paleozoic sandstones in Southwest Sinai,
.Egypt
By
Nuclear Materials Authority, El-Maadi, Cairo,
Egypt

2. Outline
 Introduction.
 lithostratigraphy of the Paleozoic succession in Southwest Sinai.
 Geological setting of U-bearing sandstones in Southwest Sinai.
 Mineralogy and petrography of the radioactive sandstones.
 Radioactivity of the studied sandstones.
 Sandstone - type uranium deposits in the promising localities.
 Inferred U- resources in evaluated deposits.
 Summary and conclusions.

3. Introduction
The Paleozoic clastics
exposed mainly along the
NE Egypt (Eastern Desert
and Sinai).
Sinai
These clastics exposed
along the African plate
which related to the Arabo-
Nubian massif.
The Paleozoic success-
ion in Sinai (up to 320m)
form the basal units of the
sedimentary sequence
unconformably overlies
the Precambrian basement
rocks.
Geological map of Egypt

4. ….Introduction Cont
The Paleozoic sandstones
exposures in Southwest Sinai
are distributed mainly as a strip
extend from Um Bogma - G.
Dhalal area, separating the
crystalline area of southern Sinai
from Mesozoic and Tertiary rocks
of El Tih and Egma Plateaux of
central Sinai. Um
Bogma
G. Dhalal
These exposures exist either
as small bodies resting on the
top of high, peneplained Ras
basement rocks or as down- Millan
faulted blocks against crystalline
basement mountains. Simplified geologic- geomorphic map showing the distribution of
.Paleozoic rocks and the studied localities in Southwest Sinai

5. The studied localities (host to sandstone-type
uranium mineralization) in Southwest Sinai:
 W. El Sahu area (SE. Um Bogma)
 G. Adedia
 G. Um Hamd
 G. Abu Triefia
 G. Maghara
 G. Hemeyir area
 El Khamila
 G. Hemeyir
 G. Ghorabi
 Ramlet Hemeyir
 W. El Main area
 W. Qarqur
 W. Imlieh
 W. Um Gidy
 Ras Millan area
 W. Lethi
.Geological map shows the studied localities in Southwest Sinai

6. Lithostratigraphy of the Paleozoic succession in Southwest Sinai
Stratigraphic units included in this study

7. Lithostratigraphy of the Paleozoic succession in Um Bogma area (a) and annotated
outcrop photographs showing in detail its Cambro-Ordovician and lower
Carboniferous formations (b,c).

8. Lithostratigraphy of the Cambro-Ordovician succession in Ras Millan area (a) and annotated
outcrop photographs showing in detail the radioactive sandstones of Araba Formation (b,c)
and composite lithostratigraphic subdivisions of Adedia Formation (e) and detailed
lithostratigraphic section of its radioactive uppermost part (f) and its annotated outcrop
photographs (d,g) in south W. El Sahu area.

10. The radioactive basal conglomerate in Southwest Sinai
The anomalous
polymictic cong-
lomerate lenses
are well extend-
ed in:
W. El Main
W. Qarqur,
W. Um Gidy,
W. Imlieh,
G. Nukhul
G. Adedia.
The lenses
Thorite
range in
thickness from
60 cm to 2.0 m
a. Polymictic basal conglomerate directly overlying the basement rocks at W. Qarqur
b. Radioactive polymictic conglomeratic lens at the base of Araba Fm., W. El Main area.
c. Rock fragments, xenotime and quartz cemented with carbonates (pointed by arrows), iron oxides
and
Fe-Ti cements in the conglomerate of W. Nukhul. (P.L., X=32).

11. The radioactive ferruginous
sandstone of El Adedia Fm.
in W. El Sahu area
Wadi Sahu Wadi El Sahu
28o 58 ' 33 " N
33o 22 ' 39 " E
LANDSAT of Wadi El Sahu, Southwestern Sinai.
U- bearing ferruginous sandstone

12. ….The radioactive ferruginous sandstones in W. El Sahu area Cont
.G. Um Hamd

13. The radioactive ferruginous sandstones in G. Hemeyir area
El Khamila
G. Hemeyir
14E 32 33

14. U- bearing ferruginous sandstones in G. Hemeyir area
.Photograph show the aeolian sands cover the exposures of U- bearing ferruginous sandstones

15. Ramlet Hemeyir
Gaba
l G ho
rabi
Ramlet Hemeyir Gabal Ghorabi
29o 03 ' 53 " N
29o 00 ' 59 " N
33o 29 ' 03 " E
33o 30 ' 19 " E
.Radioactive localities in G. Hemeyir area mostly covered with aeolian sand

16. Map of airborne gamma ray spectrometry survey which carried out on
the eastern side of the Gulf of Suez at Abu Zeneima-El Tor stretch
)(4000 Km 2
ea
yir ar
eme
G. H
d
an a
m a a re
B og ahu
Um lS
.E
W
S.

17. The radioactive Cambro-Ordovician sandstones in Ras Millan area
Uc up to 1064ppm & 8359 ppm Th

18. The Lower Carboniferous Abu Thora Formation
Abu Thora Fm.
The lower Carboniferous Abu Thora Fm.
exposed only in Um Bogma area and its
vicinities. It is up to 242m in thickness.
Three main lithofacies could be distinguished
from base to top;
 Ferruginous sandstone lithofacies.
 Varicolored siltstone and shale lithofacies.
 Milky white sandstone lithofacies .

19. The Lower Carboniferous Abu Thora Formation
33 22' 33 23' 33 24'
P3 33 20' 33 25'
G . U m R in n a
Q 29
a
S IN A I 05'
Uranium within Abu Thora Formation
B ab
W . S e ih
P3 W .S e ih ib
a se
W .
29
W .
tN
G.
e 29
N as
S a r a b it
rr
is controlled with major structure lines 04' P 2
Di
P3
E l K h a d im
Q P3 2
04'
e
ib
P 2
a
ab
P3 2
.B
P3 P A b u H a m a ta 29
W
1
2
such as: W U m B ogm a 00'
5 km
Q .M P 2
P3
W .
2
P3
W .A bu E l
or K ey M ap
N as
P 1
ei
P 3
2
P 1
2
2
P 1
2 d
e ib
P 1
Q
a
M o g h e ira t
2
Q
B ab
P 1
P
2
P 2
T a le t
1
2 2
P 1
2
P P 2
W .
TS
S e lie m
2
2 2
P 2
2
P 3
P3
NS
N-S normal fault of W. El Kharig P
2 2
2
P1 P P
P
1
3 2
2
AM 2 2
29 Q
P P3 29
03'
extending to Ras Nukhul and El
2
2
P1
W .
P 3
2 P 3
2
Pc 03'
N as
P3 P3 P 3
2
P 2
2
P3
Khaboba localities. P
e ib
2
2
P 3 P 3
2
P
2
2
Legend 2
Q W a d i D e p o s it s Q Pc
A b u T h o ra F m . P 3
2 P3 P 1
2
P
P 33 S a n d s to n e a n d
C a r b o n a c e o u s c la y
P 1
2
P 3
2
P3
P2 U m Bogm a Fm . P 2
2
P 3 U p p e r d o lo s to n e m e m b e r
P P 3 P3 P 1
Q
2 3
P
NW-SE normal fault of W. Naseib
2 2 2
2
P 22 M i d d l e i n t e r c a l a t io n m e m b e r 2
AT
P 3
P 2
P3 P3 2
or
u -T h
2
P 12 L o w e r d o lo s to n e m e m b e r
29 e tAb Pc
P1 S a r a b it, A b u H a m a ta a n d D abb 29
extending as a right limb of W. El Sahu 02' A d e d iy a F m s .
S a n d s t o n e , p e b b ly S a n d s t o n e P P 1
02'
3 2
P3
2
a n d S ilt s to n e P 1
2
B asem ent R ocks P 2
2
Pc P 2
P 2
graben.
G r a n o d io r ite a n d d io r ite 2 2
P 2
2 Q
D i p - S l ip F a u l t
P P 1 P3 P 1
P3
1
2
Pc
2 2
L o c a t i o n o f l it h o s t r a t i g r a p h i c
s e c tio n
P3 P 1
2 P 3
2
P
29
3
2
0 .0 0 .2 0 .4 0 .6 k m
P3 01'
P
30"
1
2
P3
P 1
2
P 2 P 3
2 P 3
2
2
33 22' 33 23' 33 24'
Geological) : mapl o ofi c Ump Bogmai Nareab (after BElb AassyS et t hal., s t e r n S i n a i .
F ig .( 2 G e o g m a o f W a d a s e i - W a d i a a a r e a , o u w e
2006).

21. Mineralogy of the polymictic basal conglomerate
Thorite Uranothorite
Zircon
Thorite is the most abundant Th-bearing mineral associated with other detrital
heavy minerals; including abundant uranothorite, thorianite, monazite, zircon,
xenotime besides cheralite (Th, Ca, Ce)(PO4, SO4), chevikinite (Ca, Ce, Th)4
(Fe, Mg)2(Ti, Fe)3O22 and thorutite (Th, U, Ca) TiO2.

22. .Mineralogy of the ferruginous sandstones of El Adedia Fm
The principal minerals Xenotime
Xenotime
responsible for the radioactivity:
 The refractory xenotime,
apatite, allanite, euxenite
zircon, monazite as well as
secondary U minerals;
Xenotime
Saleeite and becquirelite
in W. El Sahu area.
Uvanite and threadgoldite
in G. Hemeyir area.
The gangue minerals
Uvanite
mainly are iron oxides;
magnetite, goethite, ilmenite
in addition to barite and
galena.

23. .Mineralogy of the Araba sandstones at Ras Millan area
Autunite Allanite
Sodium meta-autunite
Monazite
The minerals responsible for
radioactivity are zircon, allanite,
thorite, xenotime, monazite, davidite
Zircon
and secondary U minerals; saleeite,
johannite and sodium meta-autunite.
The aluminium phosphate
minerals; goyazite, florencite, Zircon grains cemented with Fe-Ti oxides
plumbogummite were associated in
the anomalous sandstones.

24. Black sand lenses in El Adedia and Araba formations
The black sand lenses occur within the radioactive
horizons of El Adedia and Araba formations.
Meander loops and channels with deep scours appear to
be the most favourable sites for these lenses.
It consist of heavy minerals concentrate include
zircon, monazite, xenotime, ilmenite, ilmenorutile
and rutile. Well rounded monazite and zircon are
the most abundant minerals.
The framework grains coated with iron and titanium
oxides cement.
The cement materials occur as fibrous, radial and
acicular forms.

25. Mineralogy of the radioactive Abu Thora sandstones
Graphite
 The anomalous U content
in Abu Thora Fm. (Uc up to
Sphene
380 ppm) is controlled
mainly by the presence of U-
bearing detrital grains.
 These detrital minerals are Apatite
sphene, apatite, euxenite, Zircon
zircon and monazite.
 The leached U hosted in
the interbeded mudstones
and siltstones is captured by
the iron oxides, clay minerals
and organic matter contents.
 U occurs as spots within
other minerals as graphite.
Euxenite

26. Radioactivity of basal conglomerate lenses
The basal conglomerate lenses have anomalous eU and eTh contents
(reach up to 157 ppm eU and 2379 ppm eTh).
The eTh/eU ratio for these sediments ranges from 1.3 to 18.2 with an
average of 5.3.
The chemical uranium (Uc) is depleted in this lithofacies (reach up to 40
ppm at W. Qarqur). It ranges from 14 to 40ppm with an average of 23.2ppm.
The high Th content is attributed to high concentration of Th and Th-U
bearing minerals such as thorite, chevikinite, cheralite, thorutite, thorianite,
zircon, monazite and xenotime.
These radioactive minerals essentially exist as inclusions in the rock
fragments (framework components) or through detrital matrix and/or cement
materials.

27. Radioactivity of ferruginous sandstones in south W. El Sahu area
The ferruginous sandstones has anomalous Uc; up
to 3000 ppm in south W. El Sahu area; G. Abu Triefia
The anomalous sandstones in G. Um Hamd, G.
Abu Triefia and G. Um Karasy show high radiometric
measurements and are enriched in radionuclides; eU,
eRa and K%. Wadi Sahu
G. Um
 eU content reached 2040 ppm with an average of
Hamd
506 ppm.
 Ra content reached 1528 ppm, with an average of G. Um
Karasy
396 ppm.
The high uranium and radium contents are
attributed mainly to the presence of tongues and
lenses of secondary U-mineralization.
The Uc/eU ratios of these sandstones ranges from
0.41 to 5.1 with an average of 1.51. G. Um
The eU/eRa ratios for most of the mineralized Hamd
samples exceed unity, reflecting a state of radioactive
disequilibrium between uranium and its daughters. G. Um
Karasy
G. Abu
The above ratios indicates the enrichment of Uc in Triefia
these sandstones in the form of secondary uranium
mineralization such as saleeite and becqurelite.

28. Radioactivity in G. Hemeyir area
a Gabal Hemeyir
29o 01' 36" N
33o 32' 38 " E
2400 ppm
G.Hemeyir
b
El Khamila
c 29o 01' 38 " N
a 33o 32 ' 32 " E
> 550 ppm
b
c
G. Ghorabi
29o 01' 38 " N
33o 32 ' 32 " E
> 400 ppm
LANDSAT of Gabal Hemeyir, southwestern Sinai.

29. ….Radioactivity in G. Hemeyir area Cont

30. ….Radioactivity in G. Hemeyir area Cont
 Chemical uranium (Uc) in the ferruginous sandstones reach up to 2400ppm with an
average of 399.6 ppm.
 Uc/eU ratios for the ferruginous sandstones in G. Hemeyir area ranges from 0.49 to
27.5 with an average of 7.7.
 The eTh/eU ratio ranges from 0.12 to 0.44 with an average of 0.36.
 The radioactive sandstones at G. Hemeyir area are related to three successive
horizons include;
 The ferruginous sandstone at the topmost part of El Adedia Formation.
 The lateritic soil directly overlying the first and is represented by ferruginous siltstone (~ 1.5 m in
thickness).
 The third horizon is the violet and mottled white S.S. at the base of Abu Thora Fm., with Uc reach up
to
212 ppm.
The enrichment of uranium in these sandstones under conditions where uranium
was removed from its source and re-deposited in permeable fault zone with
continuous recharge and a basic dyke act as a barrier to U-bearing solutions.

31. Radioactivity of Araba Formation in Ras Millan area
The anomalous sandstones are highly
radioactive along the fault zone (extend ~12 km);
its activity is variable along this extension.
The radioactive horizons are:
 The basal quartzite of Araba Fm. (Uc up to 102
ppm and Th up to 7433 ppm).
Ras Millan area
The very fine sandstone at the topmost part of
Araba Fm. (Uc up to 1016 ppm and Th up to
8359 ppm).
The high eTh/eU ratios range from 1.68 to 25.6
with an average of 9.08.
This ratios reflect the presence of detrital
radioactive Th and Th-U bearing minerals like .
xenotime, allanite, monazite, thorite, zircon and Fm
davidite. a ba
r
A

32. ….Radioactivity of Araba Formation in Ras Millan area Cont
The highest radioactive measurements
were located at the downstream of W. Lethi
(eTh = 8359 ppm and eU = 450 ppm) in
Araba very fine sandstones.
The sandstones far from the fault zone
are slightly enriched in uranium than thorium
(Uc ~ 100 ppm in average).
 U liberates from the lattice of refractory hi
Let
W.
minerals during the hydrothermal alteration
Cam
bro
processes along the permeable fault zones
-Or
dov
and re-precipitated as secondary uranium
i ci a
ns
and
(e.g. saleeite, johannite and sodium-meta-
Ca
st o
mb
nes
ro-
autunite) in the overlying sandstones. This
Ord
ovi
explains the high value of both Uc and
cia
ns
and
eTh/eU ratio in the same time in these
s ton
es
sandstones.

33. Radioactivity of Abu Thora Formation
S. No. Lithofacies eU eTh Ra K% eTh/eU
The Uc/eU ratio in most of
Ferruginous
the mineralized and non 1 sandstones 13.4 10.4 16.2 0.62 0.81
mineralized samples greater Coal bearing
2 9.72 19.78 6.61 0.36 2.12
than 1. It ranges from 0.09 to black shales
58 with an average of 12.7. 3
Varicolored
24.72 37.09 18.0 0.24 1.91
siltstones
4 White sandstones 6.0 2.83 1.16 0.035 1.5
There is negative relation
between the eTh/eU ratios and
Uc indicates some enrichment
of U relative to Th (U was
enriched during secondary
processes). Uc in White S.S.
Uc in ferruginous S.S.
1 Uc in Shales
Uc in Siltstones
The close spatial correlation
between U-bearing sandstones
and major structures in the
area suggested that the 50 51 52 53 54 55 56 57 58 59 60
supergene enrichment of U in Average U concentration in ppm
these clastics was facilitated by
tectonic movements.

34. Sandstone–type uranium deposits in the promising localities
The studied Paleozoic sandstones in southwest Sinai host two types of uranium
:mineralization
1. The syngenetic continental/littoral paleoplacers; include mainly refractory
minerals which are detrital from nearby source rocks.
 Two types of placers can be recognized on the basis of depositional
environment; stream and beach placers.
 The stream placers hosted mainly in the basal polymictic conglomerate
lens directly overlying the basement rocks and in black sand lenses
exist in the sandstones of El Adedia and Araba formations.
 The refractory minerals concentration is depositional controlled and its

35. …Sandstone–type uranium deposits in the promising localities Cont
2. The tectolithologic sandstone- type uranium deposits
 It formed by the epigenetic enrichment of uranium within the sandstones
unconformably overlying the Precambrian granitic basement rocks or faulted
against it.
 The present U deposits are related to the permeable fault zones and stacked
as discordant bodies through more than one stratigraphic horizon.
 The sandstones enriched in secondary uranium minerals include uranium
phosphates and vanadates in addition to detrital mineral grains; xenotime,
sphene, apatite, zircon, monazite, euxenite, fergusonite and allanite.
 The concentration of xenotime (YPO4) and associated authigenic Al-phosphate
minerals may have been formed by dissolution of the detrital minerals by

37. Estimation of inferred U resources in uraniferous blocks of G. Um Hamd- W. El Sahu area.
Average Ore Metal
Density, Average
S. No. Block No. Area, m 2
thickness, amount, amount,
g/cm3 grade, %
m ton ton
SH333F-
1 708.77 2.8 2.639 5237.25 0.054 2.83
VC1
SH333WC
2 733.2 2.56 2.739 5141.08 0.075 3.86
2
SH333V-
3 5986.78 1.2 2.498 17946 0.014 2.51
FD1
4 SH333FD2 2500 1.2 2.712 8136 0.014 1.14
5 SH333FD3 2500 0.6 2.712 4068 0.014 0.57
SH333V-
6 2500 1.8 2.359 10615.5 0.014 1.49
FD4
7 SH333FD5 1909.38 1 2.712 5178.24 0.018 0.93
SH333F-
8 9920.55 1.77 2.716 47691.3 0.023 10.97
WD6

38. I. The inferred U resources in G. Um Hamd - W. El Sahu area.
No. of No. of No. of Estimated
Locality excavated excavated evaluated U metals
.No
Shafts trenches blocks in tons
1 G. Um Hamd 19 3 8 24.3
 The inferred U resources in G. Um Hamd locality is 28.7 ton U 3O8 or 24.3 ton U metal.
 The area south W. El Sahu; G. Abu Triefia, G. Um Karasy and G. Maghara are still under
preliminary evaluation stage.

40. El Khamila locality
G. Hemeyir
W
.
El
Kh
am
ila

41. Inferred U resource estimation in El Khamila locality
Volume determination of ore-deposits =
170m X 140m X 2.0m = 47600m3
U- grade % = 0.024%
U-ore tonnage = 111860 t ferruginous sandstone
U- metal tonnage = 26.85 t
U3 O8 – tonnage = 31.7 t
3 8

42. Summary and Conclusions
The tectonic history of southern Sinai is considered to be one of the most important
factors in the formation of the present tectonic-lithologic type uranium deposits.
 The uranium deposits hosted in fluvial sediments, which generally consist of a
sequence of conglomerates-sandstones-mudstones (fining upward sequence).
 The refractory minerals in the basal conglomerates and upper parts of Adedia and
Araba formations represent the primary source of uranium and its associated
metals in the Paleozoic sandstones.
 Another source of primary uranium is considered to be either the surrounding
uraniferous granitic provenance, or detrital granitic and/or felsic volcanic rock
fragments in the host sandstones.

43. Summary and Conclusions
 The tectonic-lithologic stack type deposits are in part considered the product of
redistribution of uranium in permeable hosts along structures took place by younger
tectonic processes.
 The uranium mineralization are rarely located far from fault zones and are stacked
up along different horizons of these permeable localities.
 The tectonic-lithologic sandstone-type uranium deposits occur in significant
quantities in the Cambro-Ordovician sandstones of G. Hemeyir, W. El Sahu and Ras
Millan areas.
 The large extension of the hosted sandstones indicates significant U-resources in
these localities in Southwest Sinai.
 Results point to the necessity for further exploration in detail.