Content uploaded by Mohamed F. Ghoneim
Author content
All content in this area was uploaded by Mohamed F. Ghoneim on Mar 24, 2015
Content may be subject to copyright.
ORIGINAL PAPER
Magmatic evolution of the area around Wadi Kariem, Central
Eastern Desert, Egypt
Mohamed F. Ghoneim &Mohamed A. Noweir &
Tamer S. Abu-Alam
Received: 13 August 2014 /Accepted: 24 February 2015
#Saudi Society for Geosciences 2015
Abstract A group of intrusive and extrusive igneous
rocks is located around Wadi Kariem, Central Eastern
Desert. These rocks have diversed petrographic compo-
sitions ranging from gabbros to granites with their vol-
canic equivalents. They belong to four distinct
Neoproterozoic units of the Eastern Desert, namely
“metagabbros (MG), older granites (OG), metavolcanics
(MV) and younger granites (YG)”. Both major and trace
elements are compiled to deduce their genetic relation-
ships. 1/Sr versus Rb/Sr and Rb/Ba versus Rb plots
suggest that these rock units exhibit comparative mag-
matic relationships. The trace element data and the nu-
merical modelling are treated according to the general
equation of partial melting (Shaw 1970)andRayleigh
equation of fractional crystallization. These rock types
favour complex petrogenetic processes during their gen-
eration. The magmatic model is based on “in-sequence”
genesis between partial melting and fractional crystalli-
zation as well as assimilation and/or magma mixing
processes in the late stage. It is evident that these rocks
resulted from five essential stages during magmatic evo-
lution of the area: (1) Meta-andesite (MV) was generat-
ed throughout partial melting (5 %) of the oceanic crust
followed by fractional crystallization (25–50 %); (2)
Gabbroic rocks (MG) were derived by partial melting
(46 %) of the oceanic crust followed by fractional crys-
tallization (20–40 %); (3) Granodiorite (OG) were de-
rived throughout partial melting (6–6.5%)ofgabbroic
parent followed by (5–20 %) fractional crystallization;
(4) Alkali-feldspar granite (YG) was derived throughout
(45–60 %) fractional crystallization of granodiorite
(OG); And finally, (5) the recorded hybrid granodiorite
rocks (HG) were generated by partial melting of grano-
diorite (OG) (24.5 %), assimilation and/or partial melt-
ing of metagabbros (MG) (11.7 %), followed by magma
mixing and (35–55 %) fractional crystallization.
Keywords Geochemical modelling .Eastern desert .
Arabian–Nubian shield .Magmatic intrusions .Partial melting
Introduction
The East African Orogen is characterized by predominantly
remobilized older crust of the Mozambique belt and the East
Antarctica (e.g. Grosch et al. 2015) in the south and juvenile
crust of the Arabian–Nubian Shield in the north (Abdelsalam
and Stern 1996). The Arabian–Nubian Shield represents a
collage of intra-oceanic island arc complexes and micro-
continental blocks that were assembled as a result of the
Neoproterozoic Pan–African Orogenic cycle (Stern and
Abdelsalam 1998;Stern2002;Abu-Alametal.2013,2014).
Stern 1993 assumed a complete Wilson cycle beginning with
rifting of the Rodinian supercontinent (900–800 Ma; e.g.
Hassan et al. 2014), followed by seafloor spreading, subduc-
tion and development of primitive arcs (810–740 Ma).
Consolidation of arc terranes, emplacement of granodioritic
batholites (e.g. Hassan et al. 2015) and the formation of the
mafic lower crust of the Arabian–Nubian Shield took place
M. F. Ghoneim :M. A. Noweir :T. S. Abu-Alam (*)
Geology Department, Faculty of Science, Tanta University,
Tanta 31527, Egypt
e-mail: tamer.abu-alam@npolar.no
T. S. Abu-Alam
Norwegian Polar Institute, 9296 Tromsø, Norway
T. S. Abu-Alam
Egyptian Institute of Geodynamic, Cairo, Egypt
Arab J Geosci
DOI 10.1007/s12517-015-1853-0
between (760–700 Ma), followed by the accretion of compos-
ite arc terranes against the western Gondwanaland.
The Pan–African rocks in the Eastern Desert of Egypt consist
of five major litho-tectonic units: (1) ophiolites (serpentinites,
metagabbro and pillow lava; e.g. Abu-Alam and Hamdy 2014),
(2) island arc metavolcanics (MV) which are intruded by (3)
calc-alkaline subduction-related metagabbro–diorite complexes
and older granitoids of tonalite–granodiorite composition (El–
Gaby et al. 1988; Ghoneim et al. 2015), (4) intermediate
Dokhan volcanics and molasses-type Hammamat sediments.
This succession was intruded by the end of the Pan–African
Orogen by (5) late and post-orogenic younger granites (YG).
High-grade metamorphic rocks appear underneath the above
described rock units as tectonic windows formed in oblique
compressional setting (e.g. Abu-Alam and Stüwe 2009), in ex-
tension setting (e.g. Fritz et al. 1996) or as strike–slip core com-
plexes (e.g. Meyer et al. 2014).
A full succession of igneous rocks, which includes intru-
sive metagabbros, older granites, younger granites and alka-
line volcanics is exposed in around Wadi Kariem, Central
Eastern Desert, which makes this area as a standard example
to study the magmatic evolution of the igneous rocks during
the Pan–African Orogen.
This paper presents new petrological and geochemical data
on the intrusive and extrusive igneous rocks in the area around
Wadi Kariem. The new data provide constrains about the gen-
esis and the tectonic significance of these rocks.
Field observations and petrography
The Wadi Kareim area is located in the Central Eastern
Desert of Egypt, to the south of Qift–Quseir road and
bounded by longitudes 33° 54′04˝34° 08′39˝Eand
latitudes 25° 59′00˝–26° 04′54˝N. The area and its
adjacent regions have been previously studied by many
investigators (e.g. Gindy 1957a,band c;El-Ramlyand
Akaad 1960; Neubauer 1962;Noweir1968;Akaadand
Noweir 1969,1980; Ghanim 1968; El Kassas 1969;
Shazly 1971; Ghoneim 1973; Abu Anbar 1988;Al
Boghdady and Van Den Kerkhof 2001). The country
rocks exposed in the area comprise the following rock
units: schists, dismembered ophiolites (mainly
serpentinite), metavolcanics, intrusive metagabbros, older
granites, younger granites, Dokhan volcanics and alka-
line volcanics (Fig. 1). In the following section, the field
Fig. 1 Geological map of the study area
Arab J Geosci
Tab l e 1 Chemical data for the 16 representative samples of intrusive and extrusive igneous rocks
Metagabbro (MG) OG Granodiorite (HG) Alkali-feldspar granite (YG) Metavolcanic (MV)
Sample 101a 101b 101c 101d 35 112 119i 123 106 68 69 70 84c 128 22 10
SiO
2
47.7 47.6 47.7 47.1 67.1 66.7 69.0 67.4 73.7 68.5 71.4 66.1 75.7 59.0 53.9 58.5
TiO
2
0.8 0.8 0.84 0.81 0.8 0.71 0.66 0.78 0.69 0.18 0.41 0.84 0.07 0.77 1.66 0.72
Al
2
O
3
18.5 18.9 17.5 18.7 15.1 15.3 15.0 15.0 15.2 14.1 14.5 16.0 13.3 18.4 13.7 17.2
Fe
2
O
3
8.47 8.3 9.41 8.90 3.7 4.13 3.64 4.28 4.28 1.92 2.09 4.06 1.27 7.87 9.07 7.35
MnO 0.1 0.12 0.14 0.13 0.03 0.06 0.04 0.06 0.08 0.03 0.02 0.04 0.01 0.11 0.15 0.11
MgO 11 10.8 11.2 11.6 1.04 2.09 1.61 1.83 0.35 1.04 0.65 1.21 0.15 5.24 2.60 4.9
CaO 10.5 10.2 10.2 10.1 3.74 4.03 2.53 3.44 1.14 2.39 1.65 3.17 0.63 1.54 6.36 1.44
Na
2
O 2.33 2.66 2.37 2.21 4.57 4.65 5.12 4.4 4.17 4.16 3.43 4.42 3.8 4.51 3.32 4.21
K
2
O 0.25 0.28 0.25 0.19 2.2 2.12 2.11 2.5 4.21 3.91 5.65 3.8 4.89 2.33 1.10 2.18
P
2
O
5
0.09 0.09 0.10 0.10 0.16 0.13 0.11 0.15 0.06 0.19 0.09 0.22 0 0.09 0.55 0.08
Trace elements (ppm)
Ba 57 75 69 81 533 346 360 401 370 922 1432 1069 253 707 82 136
Cr 358 401 380 239 55 88 45.9 64 9 10 11 11 25 71 46 183
Cu 64 56 71 46 6 16 20 34 3 6 4 5 3 28 81 30
Nb 2 3 2 2 8 7 7 8 28 16 7 19 25 4 3 4
Ni 224 257 214 235 32 53 27 39 7 6 7 7 15 25 27 63
Pb 03 22 136791711149462 44
Rb 7 7 5 5 39 45 46 55 117 81 87 75 89 48 3 11
Sr 297 332 345 282 284 305 282 280 124 362 376 401 78 293 236 273
V 123.6 139.9 141 117.2 78.9 92 74.9 85.8 11.7 44.4 30 58.8 2.9 171.7 322 189
Y 15 17 16 14 39 23 24 25 25 11 6 17 16 18 31 13
Zn 63 57 57 54 63 39 44 57 50 69 37 73 75 65 81 65
Zr 74 83 75 71 318 253 266 270 130 300 165 239 71 81 107 76
Arab J Geosci
observations will be described for all the rock units, but
the petrographic observations will be described only for
the metavolcanics, the intrusive metagabbros, the older
granites and the younger granites.
The schist is the oldest rock unit in the study area and
comprises a succession of distinctly interbedded assem-
blage of calcareous pelitic and semipelitic schists togeth-
er with subordinate mature metaquartzites and immature
metagreywackes. The schist crops out at the northwestern
part on the map area and is encountered as a small
wedge shaped. Its length reaches up to 6.4 km and its
wide range between 0.8 and 2 km. This rock unit ex-
tends from Wadi Abu Ziran in the north to Wadi Um
Shaghir in the south. The schists are bounded from the
east by Dokhan volcanics; from the west, the schists are
intruded by older granites, while the younger granites
bounded these schists from the east and the south.
Small rock units of schists are exposed around Wadi
Um Shaghir and the northwestern of Gabal Um
Shaghir. Other small outcrops occur around the asphaltic
road as small islands. The field relations between the
schists and the surrounding rock units are clearly intru-
sive and extrusive contacts, where the contact between
the schists and the alkaline volcanics is extrusive contact,
while the contact between the schists and the younger
granites is intrusive contact. Plutons of the older granite
in the form of a tongue-like body intruded these schists.
The schists are foliated and lineated and show a style of
small syncline fold. This small fold is a normal extent of
Meatiq dome. This fold is trending NNW–SSE. The east-
ernlimbisdippingWSWwithanaveragedippingvalue
of 74
°
while and western limb is dipping ESE with an
average value of 60
°
.
The dismembered ophiolites appear mainly as elon-
gated bodies, and lenses of serpentinites extend NW–SE
parallel to the main structural tend in the study area.
35 45 55 65 75
0
3
6
9
12
15
18
Nephelin
P-N
B+T
P-T
Phonolite
Benmorite
Mugearite
Hawaiite
Basalt
B-A Andesite
Dacite
Trachyandesite
Rhyolite
Trachyte
SiO2
Na2O+K2O
(b)
(a)
SiO2
Na2O+K2O
Ijolite gabbro
Gabbro Diorite
Granodiorite
Granite
Alkaligranite
Syenite
Nepheline
syenite
Syeno-diorite
Syenite
40 50 60 70
2
4
6
8
10
12
14
16
Symbole that used
OG
MG
MV
YG
HG
Fig. 2 a The chemical
classification and nomenclature
of plutonic rocks using alkalis
versus silica (TAS) diagram of
Cox et al. (1979) adapted by
Wilson (1989) for plutonic rocks.
The curved solid line subdivides
the alkalic from subalkalic rocks.
bThe chemical classification and
nomenclature of volcanic rocks
using alkalis versus silica (TAS
diagram of Cox et al. (1979))
Arab J Geosci
The serpentinite bodies are composed mainly of talc
carbonites. Small chromite lenses can be found. The
serpentinite bodies thrust over the metavolcanics and
are intruded by the metagabbros and the alkaline
volcanics.
The Dokhan volcanics are the surface and near-
surface manifestations of the plutonic calc-alkaline mag-
matic activity. The Dokhan volcanics comprise a com-
plex association of intermediate porphyritic volcanics
together with subordinate pyroclastics. The rock associ-
ation occurs in two separate outcrops. The first outcrop
covers an area of about 60 km
2
at the central part of
the map district. The second outcrop occupies an area
of about 6.5 km
2
at the northwestern part of the map
district, along the main asphaltic road. The Dokhan vol-
canics have extrusive contacts with all surrounded rock
unites.
The alkaline volcanics cut the older rocks of the basement
complex and occur in the present map area in the form of
sheets, plugs and dykes and are accessible by desert tracks
running through Wadi Kareim. Gabal Umm Shaghir repre-
sents a landmark in the study area, which consists of alkaline
volcanics.
Metagabbros (MG) occupy an irregular outcrop,
about 18 km long by 1.2–4 km wide, in the central
northern part of the map area. The outcrop extends
NW–SE parallel to the regional trend of the area.
Another small irregular outcrop of about 4 km
2
is lo-
cated in the central part of the area to the east of Gabal
El- Degheimi. Metagabbroic rocks possess light to dark
grey colours and include metagabbros and metadolerites.
They consist of plagioclase (An
40
-An
55
), hyperthene, au-
gite as relics, hornblende, actinolite and minor biotite.
The biotite is partially altered to chlorite, whereas pla-
gioclases are saussuritized. Magnetite and hematite are
common opaque minerals. The MG rocks possess relic
ophitic, subophitic and intersertal textures.
Metavolcanic rocks (MV) occupy roughly oval outcrops in
the eastern part of the map. They occupy about 85 km
2
and are
trending in a NW–SE direction. The MV includes
metarhyodacite, metadacite, meta-andesite and metabasalt.
They are characterized by a blasto-propheritic texture, where
quartz and plagioclase form phenocrysts, embedded in a
ground mass composed of small crystals of plagioclase, horn-
blende, epidote and iron oxides. Spherulitic and intersertal
textures are characteristic for the metarhyodacite and meta-
andesite, respectively.
(c)
(b)
(a)
Tholeiitic
Tholeiitic
Calc-Alkaline
Calc-Alkaline
Na O+K O
22
Na O+K O22
MgO
MgO
FeOt
FeOt
Al O
23 MgO
O
23
Fe O +Ti 2
Tholeiitic
Tholeiitic
Calc-Alkalin e
Calc-Alkalin e
Komatite
Komatite
11012
40
50
60
70
80
Alkalinit
y
Ratio
SiO
2
Peralkaline
Alkaline
Calc - alkaline
(Strongly alkaline)
29876543
Fig. 3 a FeOt-Na
2
O+K
2
O-MgO magma type diagram after Irvine and
Baragar 1971.bAl
2
O
3
-FeO*+ TiO
2
-MgO magma type diagram after
Jensen 1976.cWright alkalinity ratio variation diagram after Wright
1969.Symbols as Fig. 2
Arab J Geosci
Granitic suite includes granodiorite related to the older
granite (OG) and alkali-feldspar granite related to the younger
granite (YG). They cover mainly the western part of the study
area. The YG is separated from the OG by a narrow schist belt.
The YG plutons possess elongate outcrops, with their longer
axes trending NNW–SSE, parallel to the regional trend of the
study area.
The tonalite and granodiorite are the most common rock
varieties of the OG. Quartz, plagioclase (An
5
-An
15
), horn-
blende and biotite are abundant minerals, whereas apatite
and zircon are accessories. Biotite is altered to chlorite and
muscovite, while the feldspars are altered to sericite.
Magnetite and minor hematite are the common opaque
minerals.
Petrographically, the YG is differentiated into
synogranite and alkali-feldspar granite. Quartz, micro-
cline, orthoclase and plagioclase (An
8
-An
22
)arethe
most essential minerals. Biotite and hornblende are the
mafics. The feldspars are altered to sericite and epidote.
Hematite is the common opaque mineral.
Recorded hybrid granodiorite (HG) is a product of
reaction between intruding granitic magma and
metagabbros. Both petrography and field evidences con-
firm the presence of small- (<2 mm) and large-scale
(>15 cm) mafic bodies of the MG enclosed within the
HG. These small bodies composed mainly of horn-
blende, iron oxides and chlorite. Quartz, zoned plagio-
clase and short orthoclase laths are the common essen-
tial minerals. The feldspars altered to sericite, while the
biotite altered to chlorite. Zircon, apatite, sphene and
iron oxides are common accessories. The hypidomorphic
texture is the common texture in this rock unit.
Geochemistry
Chemical data of 16 representative samples from the above-
mentioned intrusive and extrusive igneous rocks are analysed
by XRF in Osaka City University, Faculty of Science,
Department of Geosciences. These data are presented in
Tab le 1.
The analysed samples are plotted on the (TAS) diagram
of Cox et al. (1979) adapted by Wilson (1989) for plutonic
rocks (Fig. 2a); all rock units fall near the curved solid line
that subdivided the alkalic from subalkalic rocks. The pres-
ent granitic rocks fall in the alkali-feldspar granite (YG)
and granodiorite (OG and HG) (excepted one sample of
YG lies in the syeno-diorite field). The MG samples ex-
hibit gabbro composition (Fig. 2a). Metavolcanic (MV)
samples are plotted on the (TAS) diagram of Cox et al.
(1979) for volcanic rocks (Fig. 2b); the MV samples fall
within the fields of trachy-andesite, andesite and basaltic
andesite.
The granitic rocks belong to both calc-alkaline (OG
and HG) and alkaline magma (YG) (Fig. 3a–c).
80
(c)
(b)
(a)
60 65 70 75
0
200
400
600
SiO2
A- type
I - type
Zr
R1
R2
0 500 1000 1500 2000 2500 3000
0
500
1000
1500
2000
2500
5
4
3
2
1
6
7
1 - Mantle Fractionates
2 - Pre-late Collisio n
3 - Post-Collision Uplift
4 - Late-Orogeni c
5 - Anorogeni c
6 - Syn-Collisio n
7 - Post-Orogeni c
1 10 100 1000
1
10
100
1000
VAG+
Syn-COLG
WPG
ORG
Y
Nb
Fig. 4 a Zr-SiO
2
plot after Kleeman and Twist 1989.bTectonic setting
of granites after Pearce et al. 1984.cR1-R2 discrimination diagram of
tectonic setting after Batchelor and Bowden 1985
Arab J Geosci
550 2 0 75 100 125 150 175 200 225 250
0
3000
6000
9000
12000
15000
18000
LKT- A,B
CAB -A ,C
OFB - B, D
A
B
C
D
Zr
Ti
(a)
AI
AII
B
CD
Zr/4 Y
Nb*2
(c)
CAB
IAT
MORB
OIT
OIA
MnO*10 P2O5*10
TiO2
(d)
OFB
IAB
CAB
Zr Sr/2
Ti/100
(b)
Fig. 5 a Ti-Zr tectonic setting diagram after Pearce and Cann 1973.bTi/100-Zr-Sr/2 tectonic setting diagram after Pearce and Cann 1973.cNb*2-Zr/4-
Y tectonic setting diagram after Meschede 1986.dTiO
2
-MnO-P
2
O
5
tectonic setting diagram after Mullen 1983
0.01 0.1 1 7
0.001
0.01
0.1
Rb/Sr
1 / S r
Simple mixing
FC
PM
Fig. 6 Diagram Rb/Sr-1/Sr. The
arrow (FC) indicates the general
trend of fractional crystallization.
PM is the partial melting trend
Langmuir et al. 1978;symbols as
Fig. 2
Arab J Geosci
Meanwhile, MV and MG rocks show geochemical char-
acteristic for calc-alkaline rocks (Fig. 3a, b)ofisland
arc setting (Fig. 5a–d).
Regarding the paleotectonic environment, the granitic
rocks are of I type (Fig. 4a) and merging between volcanic
arc granite (VAG) to syn-collisional granite (Syn-COLG)
(Fig. 4b, c)(Fig.5).
1/Sr versus Rb/Sr plot (Fig. 6) displays a curved line
trend for the MG, OG, HG, YG and MV association
indicative of a sympathetic relation of mixing and frac-
tional crystallization processes (Langmuir et al. 1978).
The same geochemical observation can be seen in
(Fig. 7) which shows the relationship between Rb ver-
sus Rb/Ba. These plots suggest that these rock units
exhibit comparative magmatic relationships, particularly
between OG, MV, HG and YG.
Magma generation and petrogenic modelling
The trace element data (e.g. of the oceanic crust and
primitive mantle (Table 2)) and the numerical modelling
are treated according to the general equation of partial
melting (Shaw 1970) and Rayleigh equation of fraction-
al crystallization. The magmatic model is based on “in-
sequence”genesis between partial melting (e.g. Table 3
and 5) and fractional crystallization (e.g. Table 4)as
well as assimilation and/or magma mixing processes in
the late stage. The source of partition coefficient (Kds)
values that will be used in the following section
(Tables 6,7,8) is from Arth 1976; Allegre et al.
1977; Allegre and Minister 1978;Leemanand
Lindstrom 1978; Lindstrom and Weill 1978;Irving
1978,IrvingandFrey1978; Pearce and Norry 1979;
Schock 1979; Depaolo 1981; compilation of Henderson
1982;Dostaletal.1983; Green and Pearson 1983;
Powell 1984;Fujimakietal.1984; Green and Pearson
1985; Green and Pearson 1987;Conrad1987;and
Green et al. 1989. Mineral abbreviations that will be
used are as follows: olivine (Oliv.), orthopyroxene
(Opx.), clinopyroxene (Cpx.), phlogopite (Phlog.), mag-
netite (Mag.), hornblende (Hb.), plagioclase (Plag.), k-
feldspar (k-feld.), garnet (Gar.), apatite (Apat.), sphene
(Sph.), allanite (Alla.) and quartz (Qz.). The composi-
tional variation of the studied rocks suggested five con-
sequence stages formulating their magmatic evolution
(Fig. 8).
(Stage 1) Source magma and metavolcanic (MV) generation
The geochemical data of meta-andesite (MV—Tables 3and 4)
and the oceanic crust of Table 2are compared. They indicated
two processes, namely partial melting and fractional crystalli-
zation which could explicate the petrogenesis of meta-
andesite.
(Stage 1-a) Partial melting
The magma source of MV may be explicated by partial
melting of the oceanic crust parent. The partial melting
600 20 40 80 100 120
0.0
0.1
0.2
0.3
0.4
0.5
Rb/Ba
AFC
Simple mixing
FC
Rb
Fig. 7 Rb/Ba versus Rb diagram
showing the effect of fractional
crystallization (FC), assimilation
fractional crystallization (AFC)
and simple mixing processes on
the behaviour of trace element.
The arrow (FC) represents the
fractionation trend calculated
using Rayleigh fractionation law.
The amounts of residual melt are
also shown on the fractionation
line. The arrow (AFC) represents
the assumed general trend of
assimilation fractional
crystallization, after Stern and
Hedge 1985
Arab J Geosci
model was based on the Kds value in Table 8.The
trace element composition of the oceanic crust accord-
ing to (Taylor and McLennan 1985)wastakenasthe
source with the average normative composition as fol-
lows: olivine (66.5 %), orthopyroxene (23.5 %) and
clinopyroxene (10 %). The weight fractions of liquid
contributed by each phase during melting are olivine
(25 %), orthopyroxene (50 %) and clinopyroxene
(25 %). The obtained results for partial melting model
suggest partial melting of 5 % (Table 3).
Oceanic crust
Oceanic crust
Magma
Metagabbro
(MG)
Metagabbro
(MG)
Magma
Granodiorite
(OG)
Granodiorite
(OG)
Alkali-feldspar
granite
(YG)
Alkali-feldspar
granite
(YG)
Magma
Metandesite
(MV)
Magma
Magma
Mixing
magma
Hybrid granodiorite
(HG)
Partial melting (46 %)
Partial
melting
(5 %)
stage (1-a)
Partial
melting
(24.5 %)
stage (5-a)
Partial
melting
(11.7 %)
stage (5-a)
Partial melting (6-6.5 %)
Fractional crystallization
(20-40 %)
Fractional crystallization (5-20 %)
stage (3-b)
Fractional crystallization (45-60 %)
Fractional
crystallization
(35-55 %)
stage (5-c)
Stage (5-b)
stage (2-a)
stage (2-b)
stage (3-a)
Fractional
crystallization
(25-50 %) stage (1-a)
Fig. 8 Flow chart shows the five main stages and substages of modelling processes
Tabl e 2 Shows the trace element contents of the oceanic crust and
primitive mantel (Taylor and McLennan 1985)
Trace
elements
Ba Cr Nb Ni Rb Sr V Y Zr
Oceanic crust 25 270 2.2 135 2.2 130 250 32 80
Primitive
mantle
5.1 3000 0.56 2000 0.55 17.8 128 3.4 8.3
Arab J Geosci
(Stage 1-b) Fractional crystallization
Despite no compatibility between the data of partial
melting and the actual composition of (MV) sample
No. 128 (Table 3), these modelling data are further de-
duced by using fractional crystallization of the previous-
ly calculated melt of stage 1-a. The assumed fractionat-
ed phases are olivine (9 %), orthopyroxene (14 %),
clinopyroxene (20 %), hornblende (7 %), plagioclase
(0.1 %), garnet (40 %) and magnetite (10 %). The es-
timated trace element data from the fractional crystalli-
zation model indicate that the MV rocks most probably
formed through (25–50 %) fractional crystallization
from parent melt (Table 4).
(Stage 2) Gabbroic source magma and (MG) generation
Comparison between the trace element contents of the
oceanic crust, primitive mantle (Taylor and McLennan
1985) and present MG indicates that the latter rocks are
comparable to those of the oceanic crust rather than
those of the primitive mantle. This could be carried
out through two successive processes, viz partial melt-
ing of the oceanic crust followed by fractional crystal-
lization of the produced melt.
(Stage 2-a) Partial melting of the oceanic crust
Partial melting is the most appropriate model to inter-
pret the magma source of MG. The trace element
contents are given in Table 2(Taylor and McLennan
1985). The oceanic crust was considered composing ol-
ivine (66.5 %), orthopyroxene (23.5 %) and
clinopyroxene (10 %). The weight fractions of liquid
contributed by each phase during melting are olivine
(30 %), orthopyroxene (50 %) and clinopyroxene
(20 %). The obtained results from partial melting model
suggest that the most reliable degree of partial melting
is 46 % (Table 5).
(Stage 2-b) Fractional crystallization
The second substage to producing the MG rocks is by
further fractional crystallization of the melt produced
from substage 2-a. The assumed fractionated phases
are olivine (0.66 %), orthopyroxene (0.66 %),
clinopyroxene (0.5 %), hornblende (0.66 %), phlogopite
(25 %), plagioclase (15 %), magnetite (15 %) and gar-
net (43 %). The estimated trace element data from the
fractional crystallization model indicate that the MG
rocks are most probable to be formed through (20–
40 %) fractional crystallization from the parent magma
produce from substage 2-a (Table 9).
(Stage 3) Source magma and granodiorite (OG) generation
The comparable average values of trace elements for
both metagabbroic rock (MG) and granodiorite (OG)
reflect a great extent of the genetic relationship between
the two investigated rocks. However, applying
Tabl e 3 Oceanic crust partial
melting results Trace elements Composition of
parent oceanic crust
Estimated melt with partial
melting degrees (f)
Actual composition
of MV sample No. 128
20 % 15 % 10 % 5 %
Ba 25 119.5 156.3 225.8 406.7 707
Rb 2.2 10.44 13.6 19.5 34.5 48
V 250 672.2 710.1 752.6 800.5 171.7
Y 32 116.1 132.6 154.4 184.8 18
Tabl e 4 Fractional crystallization of source melt to produced (MV)
Trace
elements
Parent comp. of the
source melt (5 %)
Estimated composition with fractional crystallization degrees (f) Actual comp. of MV
sample No. 128
25%30%35%40%45%50%
Ba 406.7 538.6 576.2 619.5 669.8 729.3 800.7 707
Rb 34.5 45.7 48.9 52.62 56.91 61.97 68.03 48
V 800.5 270.8 239.2 214.2 193.9 177.1 163.02 171.7
Y 184.8 58.68 44.56 33.16 24.09 17.03 11.64 18
Arab J Geosci
modelling calculation by both partial melting and frac-
tional crystallization (using the trace elements of the
studied MG and OG) did not give satisfactory compar-
ative results. Therefore, a combination of partial melting
and fractional crystallization models is favoured to yield
realistic results.
(Stage 3-a) Partial melting
The most primitive MG sample (No. 101c) is used as an ap-
proximate initial source composition with the average norma-
tive composition of olivine (21 %), orthopyroxene (6.5 %),
clinopyroxene (9.5 %), hornblende (2.5 %), phlogopite
(2.5 %), garnet (4 %), magnetite (2.5 %) and plagioclase
(51.5 %). The weight fractions of liquid contributed by each
phase during melting are olivine (0.5 %), orthopyroxene
(7 %), clinopyroxene (25 %), hornblende (7 %), phlogopite
(15 %), garnet (25 %), magnetite (0.5 %) and plagioclase
(20 %). The obtained results from partial melting model sug-
gest that the most suspectable degree of partial melting will
range around the value of 6–6.5 % (Table 10).
(Stage 3-b) Fractional crystallization
The estimated melt composition calculated from stage (3-a)
(Table 10) was taken as a parent composition for further frac-
tional crystallization. The assumed fractionated phases are
hornblende (10 %), biotite (1 %), magnetite (30 %), quartz
(29 %) and plagioclase (30 %). The obtained results from the
fractional crystallization model suggest that the most reliable
degree of fractionation that yields a granodiorite (OG) might
range between 5 and 20 % fractional crystallization (Table 11).
(Stage 4) Source magma and rock generation
of alkali-feldspar granite (YG)
The petrogenetic model for the investigated alkali-
feldspar granite (YG) involves one stage including frac-
tional crystallization of the older granites (OG). The
most primitive OG sample (No. 35) was taken as a
parent composition to initiate the fractional crystalliza-
tion phase. The fractionated and separated phases were
assumed quartz (41 %), hornblende (52 %), plagioclase
(3 %), k-feldspar (2.5 %), biotite (0.2 %) and magnetite
(0.8 %). The obtained results from the fractional crys-
tallization model suggest that the most acceptable de-
gree of fractionation that yields YG would range be-
tween 45 and 60 % fractional crystallization (Table 12).
(Stage 5) Hybrid granodiorite (HG) modelling between partial
melting and magma assimilation
The geochemical data of hybrid granodiorite (HG),
metagabbro (MG) and older granite (OG), using trace ele-
ment modelling, partial melting and/or fractional crystalliza-
tion equations, have not got satisfactory comparative results.
The petrography and the field observations (e.g. the presence
Tabl e 5 Melting of the oceanic
crust and generate of MG magma Trace
elements
Composition of
parent oceanic
crust
Estimated melt with
partial melting
degrees (f)
Comp. of (MG)
sample No. 101c
45 % 46 % 47 %
Nb 2.2 4.81 4.72 4.6 2
Rb 2.2 4.8 4.72 4.6 5
Sr 130 283.58 277.74 272.1 345
V 250 499.7 495.12 490.6 141
Y 32 68.65 67.6 66.57 16
Tabl e 6 The source of Kds values of felsic rocks
Hb. k-feld. Plag. Biotite Mag. Qz. Opx. Cpx.
Ba 0.04 4.3 0.3 23.5 0.00 0.022 0.003 0.13
Cr 0.00 0.00 0.2 5.2 400 0.00 2 0.00
Nb 4 0.00 0.06 6.36 2.5 0.00 0.8 0.8
Rb 0.01 0.34 0.04 4.2 0.00 0.041 0.003 0.03
Sr 0.02 3.7 15.6 0.12 0.00 0.022 0.009 0.51
Y 6 0.00 0.1 0.03 2 0.00 1 3.1
Zr 4 0.03 1 0.00 0.8 0.00 0.033 0.18
V 8 0.00 0.00 0.00 20 0.00 7 0.00
Tabl e 7 The source of Kds values of intermediate rocks
Hb. Gar. Plag. Mag. Oliv. Opx. Cpx.
Ba 0.1 0.02 0.5 0.01 0.01 0.013 0.02
Rb 0.04 0.01 0.07 0.01 0.1 0.022 0.013
V 32 8 0.01 30 0.08 1.1 1.1
Y 2.5 11 0.013 0.5 0.01 0.45 1.5
Arab J Geosci
of mafic bodies as enclaves within the hybrid granodiorite)
favour assimilation processes between granitic magma and
gabbroic rocks as an acceptable mechanism to produce the
hybrid granodiorite magma. The concept of assimilation
using geochemical data yields satisfactory pattern.
(Stage 5-a) Partial melting
The most primitive MG sample No. 101c and OG sample No.
35 are used as approximate initial source compositions, which
were assimilated and/or mixed later to produced the HG. The
average normative composition of the gabbroic sample is pla-
gioclase (51.5 %), olivine (20 %), orthopyroxene (7 %),
clinopyroxene (12 %), hornblende (2 %), phlogopite (2 %),
garnet (3.5 %) and magnetite (2.5 %). The weight fractions of
liquid contributed by each phase during melting are plagio-
clase (6.8 %), olivine (4.8 %), orthopyroxene (14.9 %),
clinopyroxene (29.8 %), hornblende (4.8 %), phlogopite
(4.8 %), garnet (29.8 %) and magnetite (4.8 %). The obtained
results from partial melting model suggest that the most real-
istic degree of partial melting is 11.7 % that was used in as-
similation processes (Table 13).
Meanwhile, the average normative composition of the
granodiorite (OG) sample No. 35 is quartz (22.4 %), k-
feldspar (14.1 %), plagioclase (51 %), orthopyroxene
(7 %), clinopyroxene (3.31 %) and magnetite (1.9 %).
The weight fractions of liquid contributed by each phase
during melting are quartz (13.5 %), k-feldspar (13.5 %),
plagioclase (43.1 %), orthopyroxene (13.5 %),
clinopyroxene (13.5 %) and magnetite (2.7 %). The ob-
tained results from partial melting model suggest that
the most suitable degree of partial melting is 24.5 %
that was used in assimilation processes (Table 13).
(Stage 5-b) Assimilation and mixing of magma
The produced magmas (stage 5-a, Table 13) are suggested to
assimilate and mix in a definite proportion to access the HG
composition. The problem that arised is: what is the relative
mixing proportion from the two magmas that were produced
in stage 5-a, which is required for HG formation?
The mixing problem has been solved by using the pipetting
method, which was used to determine the concentration of the
different volumes. In the pipetting method, there is an impor-
tant fact, which is if the solutions have different concentra-
tions, then the volume of a solution of higher concentration
must be proportionately smaller. The volumes of the solutions
taken for a particular reaction are inversely proportional to
their concentration. In other words, the products of the vol-
umes of solutions by their concentration are equal for both
reacting substances (Alexeyev 1980). If we denote the volume
and concentration of one solution by V
1
and N
1
and the other
by V
2
and N
2
, we can write the equation as the following:
V1N1¼V2N2
In case of many mixed solutions, the equation is converted to
VtNt¼V1N1þV2N2þ⋯⋯⋯⋯⋯ þVxNx
where V
t
is the total volume of the mixed solution, N
t
is the
total concentration of the mixed solution and xis the number
of solutions that will be mixed together. By applying the
above equation to solve the mixing problem, the mixing
Tabl e 8 The source of Kds values of basic rocks
Phlog. Hb. Gar. Plag. Mag. Oliv. Opx. Cpx.
Ba 1.09 0.42 0.023 0.23 0.00 0.009 0.013 0.026
Cr 12.6 12.5 0.06 0.04 153 0.7 10 34
Nb 1 0.8 0.02 0.01 0.4 0.01 0.15 0.005
Ni 20 6.8 0.68 0.04 29 29 5 1.5
Rb 3.06 0.29 0.04 0.07 0.00 0.009 0.022 0.031
Sr 0.08 0.46 0.012 1.83 0.00 0.014 0.04 0.06
V6 3.40.270.0826 0.060.5 1.35
Y 0.03 1 9 0.03 0.2 0.01 0.18 0.9
Zr 0.6 1.5 0.65 0.012 0.1 0.012 0.18 0.1
Tabl e 9 Fractional crystallization of parent melt
Trace elements Parent comp. of
parent melt (46 %)
Estimated composition with fractional
crystallization degrees (f)
Actual composition of MG
sample No. 101c
20 % 25 % 30 % 35 % 40 %
Nb 4.72 2.09 1.66 1.29 0.99 0.74 2
Rb 4.72 4.94 5.005 5.07 5.15 5.23 5
Sr 277.74 324.3 339.29 355.99 374.8 396.3 345
V 495.12 178.9 133.31 97.3 69.4 48.17 141
Y 67.6 35.2 29.14 23.8 19.18 15.17 16
Arab J Geosci
results suggest that the most suitable mixing percentage are
(75–85 %) from granitic magma and (15–25 %) from gabbroic
magma (Table 14).
(Stage 5-c) Fractional crystallization and hybrid granodiorite
(HG) generation
Finally, the last substage to produce the HG is the fractional
crystallization of mixed melt that was produced by assimila-
tion and/or mixing process (Table 14). The Kds values that
were used are listed in Table 6. The assumed fractionated
phases are hornblende (70 %), biotite (6.2 %), magnetite
(0.02 %), quartz (23 %) and plagioclase (0.002 %). The esti-
mated trace element data from the fractional crystallization
model indicates that the HG is most probable formed through
(35–55 %) fractional crystallization from mixed melt
(Tables 15).
Conclusions
The area around Wadi Karien, Eastern Desert, Egypt com-
prises the following rock units: schists, opholities,
metavolcanics (MV), intrusive metagabbro (MG), older
Tabl e 1 0 Metagabbro (MG)
partial melting results Trace elements Parent comp. of MG rocks
sample No. 101c
Estimated melt with partial melting
degrees (f)
Actual comp. of OG
sample No. 35
5% 6% 6.5% 7%
Ni 214 30.13 30.28 30.35 30.43 32
Rb 5 32.73 31.72 31.23 30.77 39
Sr 345 346.33 344.3 343.39 342.42 284
V 141 131.26 132.15 132.6 133.06 78.9
Y 16 37.46 38.89 39.65 40.43 39
Tabl e 11 Fractional
crystallization of source melt Trace
elements
Parent comp. of
the source melt
(6–6.5 %)
Estimated composition with fractional
crystallization degrees (f)
Actual comp. of OG
sample No. 35
5 % 10 % 15 % 20 % 25 %
Ni 30.35 31.94 33.72 35.70 37.93 40.46 32
Rb 31.72 33.27 34.98 36.89 39.03 41.45 39
Sr 343.39 284.1 232.7 188.4 150.64 118.7 284
V 132.6 98.47 71.97 51.66 36.34 24.99 78.9
Y 39.65 39.18 38.69 38.19 37.66 37.10 39
Tabl e 1 2 Fractional crystallization of source older granite (OG) to produced alkali-feldspar granite (YG)
Trace elements Parent comp. of (OG)
sample No. 35
Estimated composition with fractional crystallization degrees (f) Actual comp. of
alkali-feldspar
granite (YG)
sample No. 69
40 % 45 % 50 % 55 % 60 % 65 %
Cr 55 17.72 14.61 11.83 9.37 7.21 5.36 11
Rb 39 63.60 69.13 75.73 83.78 93.78 106.5 87
Sr 284 353.2 366.5 381.7 399.3 419.9 444.5 378
V 78.9 33.89 31.63 29.66 27.91 26.37 24.98 30
Y 39 13.07 10.85 8.85 7.06 5.49 4.12 6
Zr 318 182.2 165.7 149.36 133.1 117.1 101.2 165
Arab J Geosci
granite (OG), younger granite (YG), hybrid granodiorite (HG)
and alkaline volcanics. The petrogenesis of the plutonic–vol-
canic rock types indicates relative diversity of the source
melts. They follow different descending trends, partial melt-
ing, fractional crystallization or even assimilation and/or
mixing processes. The descending line depends on their com-
positions of the source magma and the corresponding rock
types. Generally, they have similar petrogenesis and varied
modelling processes throughout. It is evident that these rocks
resulted from five essential stages and ten substages (Fig. 8)
during magmatic evolution of the area:
1. The meta-andesite (MV) was generated throughout partial
melting (5 %) of the oceanic crust followed by fractional
crystallization (25–50 %).
2. The gabbroic rocks (MG) were derived by partial
melting (46 %) of the oceanic crust followed by
fractional crystallization (20–40 %) of the resulted
magma.
3. Rocks of granodiorite (OG) were derived throughout
partial melting (6–6.5 %) of gabbroic parent follow-
ed by (5–20 %) fractional crystallization.
4. The alkali-feldspar granite (YG) was derived
throughout (45–60 %) fractional crystallization of
granodiorite (OG).
5. The recorded hybrid granodiorite rocks (HG) were
generated by partial melting of OG (24.5 %), assim-
ilation and/or partial melting of MG (11.7 %),
followed by magma mixing and (35–55 %) fraction-
al crystallization.
Tabl e 1 3 The partial melting
processes to produce mixing
magma
Trace elements Parent comp. of MG
rock sample No. 101c
Estimated melt with
partial melting degrees
(f) 11.7 %
Parent comp. of
OG rock sample
No. 35
Estimated melt with
partial melting
degrees (f) 24.5 %
Ba 69 21.4 533 636.03
Cr 380 93.66 55 10.27
Nb 2 2.77 8 24.24
Y 16 66.88 39 112.3
Zr 75 426.34 318 1060.08
Tabl e 1 4 The mixing proportion
of MG and YG to produce HG Trace elements Parent comp. of
gabbroic magma
Parent comp. of
granitic magma
Estimated melt with mixing processes
(75–85 %) of granitic magma
(15–25 %) of gabbroic magma
Ba 21.4 636.03 513.104
Cr 93.66 10.27 26.94
Nb 2.77 24.24 19.94
Y 66.88 112.3 103.216
Zr 426.34 1060.08 933.332
Tabl e 1 5 Factional crystallization of source melt to produced HG
Trace elements Parent comp. of the
source melt
Estimated composition with fractional crystallization degrees (f) Actual comp. of hybrid
granodiorite (HG)
sample No. 119i
30 % 35 % 40 % 45 % 50 % 55 % 60 %
Ba 513.104 430.09 414.61 398.51 381.72 364.14 345.65 326.08 360
Cr 26.94 34.20 35.94 37.92 40.20 42.85 45.98 49.75 45.9
Nb 19.94 9.11 7.74 6.5 5.37 4.35 3.45 2.67 7
Y 103.216 32.94 25.98 20.11 15.22 11.21 8.005 5.49 24
Zr 933.332 491.1 429.81 372.13 318.18 268.02 221.72 179.36 266
Arab J Geosci
References
Abdelsalam MG, Stern RJ (1996) Sutures and shear zones in the
Arabian–Nubian Shield. J Afr Earth Sci 23:289–310
Abu-Alam TS, Hamdy M (2014) Thermodynamic modelling of Sol
Hamed serpentinite, South Eastern Desert of Egypt: implication
for fluid interaction in the Arabian-Nubian Shield ophiolites. J Afr
Earth Sci 99:7–23
Abu-Alam TS, Stüwe K (2009) Exhumation during oblique
transpression: the Feiran-Solaf region, Egypt. J Metamorph Geol
27:439–459
Abu-Alam TS, Santosh M, Brown M, Stüwe K (2013) Gondwana colli-
sion. Mineral Petrol 107:631–634
Abu-Alam TS, Hassan M, Stüwe K, Meyer S, Passchier C (2014)
Multistage tectonism during Gondwana Collision: Baladiyah
Complex, Saudi Arabia. J Petrol 55:1941–1964
Abu Anbar MM (1988) Geology of the district around Wadi El-Dabbah,
Eastern Desert, Egypt. M. Sc. Thesis, Tanta University, 198p
Akaad MK, Noweir AM (1969) Lithostratigraphy of the Hammamat–Um
Seleimt district, Eastern Desert, Egypt. Nature 5203:284–285
Akaad MK, Noweir AM (1980) Geology and Lithostratigraphy of the
Arabian Desert Orogenic Belt of Egypt between lat. 25
o
35′and 26
o
30′. Inst Appl Geol Jeddah Bull 3:127–134
Al Boghdady AI, Van Den Kerkhof AM (2001) Fluid inclusions and
mineral chemistry of the Wadi Mahasin Gold Deposit, Center
Eastern Desert, Egypt. Ann Geol Surv Egypt 23:235–259
Alexeyev VN (1980) Qualitative chemical semi microanalysis, translated
from the Russian by Artavaz Beknazarov. Mir Publisher, Moscow,
PP 583
Allegre CJ, Minster JF (1978) Quantitative models of trace element be-
havior in magnetic processes. Earth Planet Sci Lett 38:1–25
Allegre CJ, Treail M, Minster JF, Minster B, Albarede F (1977)
Systematic use of trace elements in igneous processes. Part I: frac-
tional crystallization processes in volcanic suites. Contrib Mineral
Petrol 60:57–75
Arth JG (1976) Behavior of trace elements during magmatic processes a
summary of theoretical models and their applications. J Res US
Geol Surv 4:41–47
Batchelor RA, Bowden P (1985) Petrogenetic interpretation of granitoid
rock series using multicationic parameters. Chem Geol 45:43–55
Conrad WK (1987) A FORTRAN program for simulating major and
trace element variations during Rayleigh fractionation with melt
replenishment or assimilation. Comput Geosci 13:1–12
Cox KG, Bell JD, Pankhurst RJ (1979) The interpretation of igneous
rocks. Allen and Unwin, London, 450 pp
DePaolo DJ (1981) Trace element and isotopic effects of combined wall
rock assimilation and fractional crystallization. Earth Planet Sci Lett
53:189–202
Dostal DC, Carron JP, Guen L, de Kerneizon M, Maury RC (1983)
Partition coefficients of trace elements: application to volcanic rocks
of St Vincent, West Indies. Geochim Cosmochim Acta 47:525–533
El Kassas IA (1969) Comparative geological investigations of the radio-
active mineralization in the Central Eastern Desert. Egypt. M.Sc.
thesis, Ain Shams University, 132 p
El–Gaby S, List FK, Tehrani R (1988) Geology, evolution and
metallogenesis of the Pan–African belt in Egypt. In: El–Gaby S,
Greiling R (eds) The Pan–African Belt of NE Africa and adjacent
areas, tectonic evolution and economic aspects in. Freidr. Vieweg &
Sohn, Braunschweig, 17–68
El-Ramly MF, Akaad M K (1960) The basement complex in the Central
Eastern Desert of Egypt, between latitude 24
o
30′and 20
o
40′N.
Geol Surv Egypt. Paper No. 8
Fritz H, Wallbrecher E, Khudeir AA, Abu El Ela F, Dallmeyer DR (1996)
Formation of Neoproterozoic metamorphic core complexes during
oblique convergence (Eastern Desert, Egypt). J Afr Earth Sci 23:
311–323
Fujimaki H, Tatsumoto M, Aoki K (1984) Partition coefficients of Hf, Zr
and REE between phenocrysts and groundmasses. Proceedings of
the fourteenth lunar and planetary science conference, part 2. J
Geophys Res 89:662–672
Ghanim M (1968) The geology of Wadi Kareim area, Eastern Desert,
Ph.D. thesis, Faculty of Science, Cairo University, United Arab
Republic, 361p
Ghoneim M F (1973) Geology of the area around Bir El-Kubbania,
Eastern Desert, Egypt, M.Sc. thesis, Faculty of Science, Tanta
University, 252p
Ghoneim MF, Heikal MS, El Dosuky BT, Abu-Alam TS, Sherif MI
(2015) Neoproterozoic granites of Sharm El-Shiekh area, Egypt:
mineralogical and thermobarometric variations. Arab J Geosci 8:
125–141
Gindy A R (1957a) The geological history of the Pre-Nubian rocks in the
area between Gabal Atshan and Gabal Hamadat, south-west of
Quseir, Red Sea province, Egypt. Second Arab Science Congress
1955, Cairo, 241–249
Gindy A R (1957b) The igneous and metamorphic rocks of the area
between Gabal Atshan and Gabal Hamadat, near of Quseir,
Eastern Desert of Egypt, Bull Inst Egypt vol. 38
Gindy A R (1957c) The succession and correlation of the pre-Nubian
Sandstone rocks around the phosphate mining district of Quseir,
Red Sea province. Bull Faculty Sci Cairo University No. 38
Green TH, Pearson NJ (1983) Effect of pressure on rare earth element
partition coefficients in common magmas. Nature 305:414–416
Green TH, Pearson NJ (1985) Experimental determination of REE parti-
tion coefficients between amphibole and basaltic liquids at high
pressure. Geochim Cosmochim Acta 49:1465–1468
Green TH, Pearson NJ (1987) An experimental study of Nb and Ta
partitioning between Ti-rich minerals and silicate liquids at high
pressure and temperature. Geochim Cosmochim Acta 51:55–62
Green TH, Sie SH, Ryan CG, Cousens DR (1989) Proton microprobe-
determined partitioning of Nb, Ta, Zr, Sr and Y between garnet,
clinopyroxene and basaltic magma at high pressure and temperature.
Chem Geol 74:201–216
Grosch E, Frimmel H, Abu-Alam TS, Kosler J (2015) Metamorphic and
age constraints on crustal reworking in the western H.U.
Sverdrupfjella: Implications for the evolution of Western Dronning
Maud Land, Antarctica. J Geol Soc (in press)
Hassan M, Abu-Alam TS, Stüwe K, Fowler A, Hassan I (2014)
Metamorphic Evolution of the Sa'al-Zaghra Complex in Sinai:
Evidence for Mesoproterozoic Rodinia Break-up? Precambrian
Res 241:104–128
Hassan M, Stüwe K, Abu-Alam TS, Klötzli U, Tiepolo M (2015) Time
Constraints on Deformation of the Ajjaj-Branch of the Largest
Proterozoic Shear Zone on Earth: The Najd Fault System.
Gondwana Res (in press)
Henderson P (1982) Inorganic geochemistry pergamon, Oxford
Irvine TN, Baragar WRA (1971) A guide to the chemical classification of
the common volcanic rocks. Can J Earth Sci 8:523–548
Irving AJ (1978) A review of experimental studies of crystal liquid trace
element partitioning. Geochim Cosmochim acta 42:743–770
Irving AJ, Frey FA (1978) Distribution of trace elements between garnet
megacrysts and host volcanic liquids of kimberlitic to rhyolitic com-
position. Geochim Cosmochim Acta 42:771–787
Jensen LS (1976) A new cation plot for classifying subalkalic volcanic
rocks. Ontario Department of Mines, Miscellaneous Paper 66
Kleeman GJ, Twist D (1989) The compositionally-zoned sheet-like gran-
ite pluton of the Bushveld Complex: evidence bearing on the nature
of A-type magmatism. J Petrol 30:1383–1414
Langmuir CH, Vocke RD, Hanson GN, Hart SR (1978)A general mixing
equation with applications to Icelandic basalts. Earth Planet Sci Lett
37:380–392
Arab J Geosci
Leeman WP, Lindstrom DJ (1978) Partitioning of Ni
+2
between basaltic
melt and synthetic melt and olivines—an experimental study.
Geochim Acta 42:801–816
Lindstrom DJ, Weill DF (1978) Partitioning of transition metals between
diopside and coexisting silicate liquids. I. Nickel, cobalt and man-
ganese. Geochim Cosmochim Acta 42:817–831
Meschede M (1986) A method of discriminating between different types
of mid–ocean ridge basalts andcontinental tholeiites with the Nb-Zr-
Y diagram. Chem Geol 56:207–218
Meyer S, Passchier C, Abu-Alam TS, Stüwe K (2014) A strike-slip core
complex from the Najd fault system, Arabian shield. Terra Nova 26:
387–394
Mullen ED (1983) MnO/TiO
2
/P
2
O
5
: a minor element discriminant for
basaltic rocks of oceanic environments and its implications for pet-
rogenesis. Earth Planet Sci Lett 62:53–62
Neubauer WH (1962) Geologie der Goldagerstatte Von El–Sid in
oberagypten miteinem Beitrag zut Geologie der zentraten
Arabischen wuste. Geol Jb 80:1–117
Noweir A M (1968) Geology of El-Hammamat–Wadi Seleimt Area,
Eastern Desert. Ph.D. thesis, University of Assiut, United Arab
Republic
Pearce TA, Cann JR (1973) Tectonic setting of basic volcanic rocks
determined using trace element analysis. Earth Planet Sci Lett 19:
290–300
Pearce JA, Norry MJ (1979) Petrogenetic implications of Ti, Zr, Y
and Nb variations in volcanic rocks. Contrib Mineral Petrol
69:33–47
Pearce JA, Harris NB, Tindle AG (1984) Trace element discrimination
diagrams for the tectonic interpretation of granitic rocks. J Petrol 25:
956–983
Powell R (1984) Inversion of the assimilation and fractional crystalliza-
tion (AFC) equations, characterization of contaminants from isotope
and trace element relationships in volcanic suites. J Geol Soc Lond
141:447–452
Schock HH (1979) Distribution of rare-earth and other trace elements in
magnetites. Chem Geol 26:119–133
Shaw DM (1970) Trace element fractionation during anatexis. Geochim
Cosmochim Acta 34:237–242
Shazly A G (1971) Geology of Abu Ziran area Eastern Desert. Ph.D.
thesis, Assiut University
Stern RJ (1993) Tectonic evolution of the late proterozoic East African
Orogen: constraints from crustal evolution in the Arabian–Nubian
Shield and the Mozambique Belt. In: Thorweihe U, Schandelmeier
H (eds) Geoscientic Research in Northeast Africa. Balkema,
Rotterdam, pp 73–74
Stern RJ (2002) Crustal evolution in the East African Orogen: a neodym-
ium isotopic perspective. J Afr Earth Sci 34:109–117
Stern RJ, Abdelsalam MG (1998) Formation of continental crust in the
Arabian-Nubian Shield: evidence from granitic rocks of the Nakasib
suture, NE Sudan. Geol Rundsch 87:150–160
Stern RJ, Hedge CE (1985) Geochronologic and isotopic constraints on
Late Precambrian crustal evolution in the Eastern Desert of Egypt.
AJS 285:97–127
Taylor SR, McLennan SM (1985) The continental crust: its composition
and evolution. Black Well, Oxford
Wilson M (1989) Igneous petrogenesis. Harper Collins Academic,
London, PP 466
Wright J (1969) A simple alkalinity ratio and its application to questions
of non-orogenic granite genesis. Geol Mag 106:370–384
Arab J Geosci
