Gondwana Research, V. 8, No. 4, pp. 457-471.
© 2005 International Association for Gondwana Research, Japan.
ISSN: 1342-937X
Gondwana
Research
A Quantitative Structural Study of Late Pan-African
Compressional Deformation in the Central Eastern Desert
(Egypt) During Gondwana Assembly
M.M. Abdeen1 and R.O. Greiling2
1
2
National Authority for Remote Sensing and Space Sciences, 1564 Alf Maskan, Joseph Broz Tito St., El-Nozha El-Gedida,
Cairo, AR Egypt
Geologisch-Paläontologisches Institut, Ruprecht-Karls-Universität Heidelberg, Germany, Im Neuenheimer Feld 234, 69120
Heidelberg, FR Germany
(Manuscript received December 1, 2004; accepted June 10, 2005)
Abstract
The Arabian-Nubian-Shield (ANS) is composed of a number of island arcs together with fragments of oceanic
lithospere and minor continental terranes. The terranes collided with each other until c. 600 Ma ago. Subsequently,
they were accreted onto West Gondwana, west of the present River Nile. Apart from widespread ophiolite
nappe emplacement, collisional deformation and related lithospheric thickening appear to be relatively weak.
Early post-collisional structures comprise not only extensional features such as fault-bounded (molasse) basins and
metamorphic core complexes, but also major wrench fault systems, and thrusts and folds. The Hammamat Group
was deposited in fault-bounded basins, which formed due to N-S to NW-SE directed extension. Hammamat Group
sediments were intruded by late orogenic granites, dated as c. 595 Ma old. A NNW-SSE-oriented compression prevailed
after the deposition of the Hammamat Sediments. This is documented by the presence of NW-verging folds and
SE-dipping thrusts that were refolded and thrusted in the same direction. Restoration of a NNW-SSE- oriented balanced
section across Wadi Queih indicates more than 25% of shortening. Transpressional wrenching related to the Najd
Fault System followed this stage. The wrenching produced NW-SE sinistral faults associated with positive flower structures
that comprise NE-verging folds and SW-dipping thrusts. Section restoration across these late structures indicates
15–17% shortening in the NE-SW direction. At a regional scale, the two post-Hammamat compressional phases produced
an interference pattern with domes and basins. It can be shown that the Najd Fault System splays into a horsetail
structure in the Wadi Queih area and loses displacement towards N and NW. The present study shows a distinct space
and time relationship between deposition of Hammamat Group/late-Pan-African clastic sediments and late stages of
Najd Fault wrench faulting: Hammamat deposition is followed by two episodes of compression, with the second episode
being related to Najd Fault transpression. Therefore, the Hammamat sediments do not represent the latest tectonic
feature of the Pan-African orogeny in the ANS. The latest orogenic episodes were the two successive phases of compression
and transpression, respectively. It is speculated that extension during (Hammamat) basin formation was sufficiently
effective to reduce the thickness of the orogenic lithosphere until it became gravitationally stable, and incapable of
further gravitational deformation.
Key words: Pan-African, Arabian-Nubian Shield, section restoration, late-orogenic structure, transpression.
Introduction
Whereas the Arabian-Nubian Shield is generally accepted
as an example of an accretionary orogen, which developed
from an assemblage of mostly intra-oceanic magmatic arc
terranes with subordinate continental terranes (e.g., Gass,
1981; Kröner, 1985; Stern, 1994), there is still no general
consensus on the evolution from the accretion to the
subsequent cratonization during the final collision
between East and West Gondwana. An early review by
Stern (1985) stressed the extensional component of
transform faulting at this stage, whereas later models
(O’Connor, 1996; Fritz et al., 1996; Smith et al., 1999)
viewed the orogeny as being dominated by transform or
transpressional processes. This is in contrast to other
models of early convergence and collision, followed by
late orogenic extension or escape (Burke and Sengör,
1986; Stern, 1994; Blasband et al., 2000). Recently, Fowler
and El Kalioubi (2004) developed a further model that
stresses nappe transport during gravitational collapse
accompanied by tectonic squeezing as the dominant
process to explain the observed deformational sequence.
458
M.M. ABDEEN AND R.O. GREILING
In general, the processes involved in convergence
include components of pure shear compression and simple
shear wrenching, i.e., transpression, which can lead to
lithospheric thickening and subsequent re-adjustment of
lithospheric thickness to normal and potentially stable
conditions. Apart from erosion and associated isostatic
re-equilibration, such re-adjustment may be achieved
by tectonic processes, in particular extensional collapse
(e.g., Dewey, 1988). This late orogenic stage of
gravitational collapse is generally regarded as the final
episode of orogenic deformation (Dewey, 1988; Blasband
et al., 2000). However, during the last decade, there is
growing evidence from the northwestern part of the
Arabian-Nubian Shield, along the suture between East and
West Gondwana, that gravitational collapse is followed
by further orogenic deformation, which is mostly
compressional or transpressional. This late-orogenic
deformational sequence has become well-established
qualitatively (e.g., references in Table 1). However, the bulk
strains associated with these deformation events has not
yet been properly quantified. Therefore, the present work
first establishes the late orogenic structural evolution of
a key region in detail and then estimates the bulk strains.
The example presented here is from a Hammamat Basin
near Wadi Queih, near the termination of a major,
regional transform zone in Egypt, the Najd Fault System
(Stern, 1985; see Fig. 1).
Regional Geology
The Arabian-Nubian-Shield (ANS) is composed of a
number of island-arc terranes together with fragments of
oceanic lithospere and minor continental terranes. Accretion
and collision established two tiers of orogenic rocks
(Bennett and Mosley, 1987). The upper tier is characterized
by sequences of low metamorphic grade with their primary
textures still discernible. The lower tier is composed of
gneissic rocks with relatively higher metamorphic grade
but with similar geochemical characteristics to those of
the upper tier. Primary contact relationships within and
between the tiers are rarely preserved due to intense
faulting and shearing. Hermina et al. (1989) and Said
(1990) provided comprehensive descriptions and
references, which are briefly summarized here.
The ANS and the Eastern Desert in particular are known
for numerous well-preserved ophiolite fragments with
sequences from layered gabbros, sheeted dykes, pillow
lavas, to black cherts (Shackleton et al., 1980; Kröner,
1985; Kröner et al., 1987; Johnson and Woldehaimot,
2003). Even more ubiquitous are bodies of ultramafic
rocks. These ophiolite fragments represent remnants
of oceanic lithosphere, which are around 800 Ma old.
They are presently preserved as parts of tectonic mélanges
or as kilometre-scale nappes. Stratigraphically above these
ophiolites occur andesitic volcanic sequences, often as
pillow lavas, and related volcaniclastic rocks. Eventually,
the volcanic rocks evolve with time towards more felsic,
sometimes even rhyolitic compositions. Sedimentary rocks
are subordinate, with mostly clastic sequences and rare
BIF, and carbonates. All of these upper tier rocks were
weakly metamorphosed (greenschist, locally amphibolite
grade), prior to the deposition of a further volcanic
sequence, the Dokhan volcanics of mostly andesitic and
rhyolitic composition. The Dokhan volcanics are overlain
by molasse-type clastic sedimentary sequences of the
Hammamat Group and felsic volcanic rocks, which may
be both extrusive (ignimbrites) or intrusive at a shallow
level. The post-ophiolite evolution of volcanic sequences
is accompanied by compositionally related plutonic rocks,
which evolved from calc-alkaline compositions (gabbro,
diorite, granitoids) to alkaline granites. Frequent posttectonic, alkaline granites and dyke swarms, which intruded
c. 600 to 550 Ma ago, represent the latest rocks of the
orogen.
Although the plutonic rocks are relatively more frequent
in the lower tier, other rock types like ophiolitic gabbro
and ultramafic rocks, calc-alkaline gabbros, granitoids,
and psammitic sedimentary rocks have also been identified
as protoliths within the gneissic sequence. Since these rock
types are similar in composition to the upper tier rocks, it
has been argued that they are time-equivalent with the
upper tier sequences. Recent radiometric work provided
evidence for such a view in some places (e.g., Gabal Sibai,
Bregar et al., 2002; location 7 on Fig. 2). However, in
other places, gneisses contain fragments of a pre-ophiolite
(continental) crust, for example at the Meatiq dome
(Loizenbauer et al., 2001, location 5 on Fig. 2).
Tectonic Evolution
The terranes collided with each other and were
subsequently accreted onto West Gondwana, or the East
Sahara Craton, west of the present River Nile, until
c. 600 Ma ago (see Stern, 1994; Unrug, 1997; Johnson
and Woldehaimot, 2003, and references therein). Apart
from widespread ophiolite nappe emplacement
(e.g., Shackleton et al., 1980), collisional deformation
and related lithospheric thickening appear to be rather
weak (e.g., Shackleton, 1986; Loizenbauer et al., 1999;
Fritz et al., 2002). For example, in the whole of the northern
part of the ANS no traces of high-pressure metamorphic
assemblages have yet been found (e.g., Stern, 1994).
Early post-collisional structures comprise extensional
features such as fault-bounded (molasse) basins
Gondwana Research, V. 8, No. 4, 2005
LATE PAN-AFRICAN COMPRESSIONAL DEFORMATION DURING GONDWANA ASSEMBLY, EGYPT
459
Fig. 1. Tectonic map of the northern part of the East African Orogen (Arabian-Nubian Shield) between continental terranes of East and West
Gondwana, respectively. Black aeras show spatial extent of ophiolite remnants, Phanerozoic cover is white; compiled from BRGM (2004),
and Johnson and Woldehaimot (2003). Thin lines represent general faults (BRGM 2004), thick lines represent Pan-African faults, potential
sutures (barbed) and strike-slip faults (arrows; from Johnson and Woldemainot 2003). Selected major elements of the NW-SE-trending
Najd Fault System (Stern 1985; Sultan et al., 1988) are marked N. The box shows the study area at the NW end of the Najd Fault System
(Fig. 2). The zone of Najd Faults is now being separated by Red Sea extension, approximately along the dashed line in the northern Red Sea.
(Grothaus et al., 1979; Osman et al., 1993; Rice et al.,
1993; Warr et al., 1999) and metamorphic core complexes
(Sturchio et al., 1983; Fritz et al., 1996; Blasband et al.,
2000), but also major wrench fault systems (Stern, 1985;
Sultan et al., 1988; O’ Connor, 1996; Abdelsalam et al.,
1998) and thrusts and folds (Greiling et al., 1994; Fowler
and El Kalioubi, 2004). Hammamat Group sediments are
intruded by late orogenic granites, dated as c. 595 Ma old
(e.g., Ries et al., 1983; Willis et al., 1988). Figure 1 shows
the regional tectonic features of the ANS as the northern
part of the East African Orogen between East and West
Gondwana, respectively. It also includes some of the
important structures of the ANS, which are relevant for
the understanding of the late Pan-African orogenic history.
In particular, the complex Najd Fault System of NW-SEtrending, sinistral wrench faults dominates the northern
ANS (Stern 1985). Detailed studies at the NW tip of this
wrench system in Egypt showed considerable NE-SW
compression and NW-SE extension after the deposition
of terrestrial, coarse- to fine-grained clastic sequences,
resembling molasse-type deposits (see Table 1).
Gondwana Research, V. 8, No. 4, 2005
The territory from Quseir in the east to Wadi Hammamat
in the west (see Fig. 2) has been the topic of numerous
studies and is recognized as a classic section through the
Pan-African basement (e.g., Hume 1934, 1937; Ries et al.,
1983; Sturchio et al., 1983; Stern, 1985; El-Gaby et al.,
1988; Sultan et al., 1988; Fritz et al., 1996). While Stern
(1985) pointed out interrelationships of transform faulting
and extension, Fritz et al. (1996) and Fritz and Messner
(1999) interpreted the structures to have originated during
orogenic compression or convergence. Detailed structural
studies in the Wadi Queih Basin (Abdeen and Warr, 1998)
demonstrated a time sequence from basin formation by
extension to (orthogonal) NNW-SSE compression and
subsequent transpression. Based on these qualitative and
directional data, detailed cross-sections parallel with the
principal compression directions have been constructed
and are graphically restored here in order to help quantify
the deformation. The results, together with published and
unpublished information from the adjacent areas are then
used to discuss the late Pan-African tectonic evolution in
the wider context of orogenic evolution and Gondwana
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M.M. ABDEEN AND R.O. GREILING
assembly. Accordingly, the geology of the Wadi Queih area
is presented first and then the evolution of the surrounding
basins of comparable tectonic setting is discussed.
The Wadi Queih Area
Geology and structural evolution
The structural geological map (Fig. 3) shows the
exposed part of the Hammamat Group in the Wadi Queih
area to be juxtaposed to the NE and SW against Cainozoic
sedimentary successions along normal faults (Fig. 3).
It is only the northern basin margin, where a primary,
unconformable contact between the underlying Dokhan
volcanics and the Hammamat sequence is preserved. The
basal part of the Hammamat sedimentary succession
consists of several tens of metres of a coarse, pebble to
cobble basal conglomerate, which contains fragments of
Pan-African rocks such as metavolcanic, related
metasedimentary, and plutonic rocks, including
undeformed, pink, younger granites, which are regarded
as belonging to the early post-collisional, alkaline granites
(e.g., Hassan and Hashad, 1990). The basal conglomerate
is overlain by a sequence, which generally fines upwards
and contains major depositional cycles in the order of a
hundred metres thick and subcycles with several metres
in thickness (El-Taky, 1988). The finer-grained parts of
these cycles contain rain-drop prints and mud crack
polygons (Abdeen et al., 1997), which indicate subaerial
conditions during deposition. Also the upper, primary
contact against “felsite” may suggest subaerial deposition
Table 1. Compilation of late Pan-African structural episodes, starting from syn-Hammamat Group extension and basin formation to subsequent
compressional and transpressional episodes. The time sequence is from left to right (latest). Location numbers are also shown on the
geological map of figure 2.
Area
(see Fig. 2)
Extension direction
Early
during basin formation shortening
Strike-slip
(sinistral) and
late shortening
(transpression)
References
Wadi Meesar
Wadi Zeidun
1
NNW-SSE
-
-
-
Osman (1996)
Wadi Hammamat
Um Had
Um Effein
2
unknown
NNW-SSE
(NNW-thrusts)
subordinate
NE-SW
(SW, NE-thrusts)
de Wall et al. (1998),
Fowler (2001),
Fowler and Osman
(2001), our data
Atalla zone
3
—-
?
subordinate
NE-SW
de Wall et al. (1998)
Fowler and Osman
(2001)
Um EshUm Seleimat
Fawakhir
4
—-
NW-SE
NNW-SSE
NE-SW
Mostafa and Bakhit
(1988),
Fowler (2001),
Loizenbauer and
Neumayr (1996),
Fowler and El
Kalioubi (2004)
Gabal Meatiq
5
—-
NW-SE
(NNW-thrusts)
NW-SE
ENE-WSW
(NNW-SSE folds)
NE-SW
Sturchio et al. (1983)
Fritz et al. (1996)
Loizenbauer et al.
(2001)
Wadi Kareim
6
NW-SE
NNW-SSE
NW-SE
''local thrusts'' NW
WSW-ENE synform
NE-SW
ENE-WSW
Fritz and Messner
(1999)
Gabal El Sibai
El Shush-Umm
Gheig
7
NW-SE
WNW-ESE
WNW-thrusts
NW-SE
WNW-ESE
NE-SW
NNE-SSW
(WNW-ESE folds)
Kamal El Din et al.
(1992)
Kamal El Din (1993)
Ibrahim and
Cosgrove (2001)
Bregar et al. (2002)
Abdeen (2003)
Wadi Umm Gheig
8
unknown
?
N-S
NE-SW
Folds, thrusts
Hamad (2003)
Wadi Queih
9
N-S?
NNW-SSE
(NNW-thrusts)
NW-SE
NE-SW
(SE-NW folds, thrusts)
El-Taky (1988)
Abdeen and Warr
(1998) our data
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LATE PAN-AFRICAN COMPRESSIONAL DEFORMATION DURING GONDWANA ASSEMBLY, EGYPT
Table 2. Numerical values on the section restorations of figures 5 and 8.
Late-stage transpression
NE-SW shortening (Fig. 8)
Deformed length
Restored length
Shortening
Early shortening,
NNW-SSE (Fig. 5)
section A - A’
section B-B’
section C-C’
4,25 km
5,10 km
17%
5,95 km
7,00 km
15%
8,05 km
10,73 km
25%
of an ignimbrite, which contains fragments of Hammamat
sediments at its base (Abdeen et al., 1991). The structural
geological map also shows the trend of (early) folds,
as E-W to ENE-WSW (Fig. 3). These folds are associated
with early thrusts (Abdeen et al., 1992; Abdeen and
Warr, 1998), and both these elements represent the effects
of a common, compressive stress field (Fig. 4) that acted
after basin formation and deposition of Hammamat Group
sediments (see Abdeen and Warr, 1998, for further
details).
The section subparallel with the major principal
stress direction (Fig. 5a) shows the geometry of the thrusts
and their relation with the early folds. The highest thrust
461
(no. 1 on Fig. 5) represents also the oldest thrust, assuming
a forward-propagating (towards NNW) thrust system.
At a later stage, this thrust system also developed an outof-sequence thrust (no. 3 on Fig. 5) in the SE of the area.
This out-of-sequence thrust cut across the hangingwall of
thrust number 1 and transported the Hammamat Group
sequence over the pre-Hammamat metamorphic sequence,
thus creating a window of Hammamat rocks. The primary
contact, at the top of the Hammamat sequence is preserved
as a weak erosional unconformity in the eastern part of
the area (Fig. 3). There, thrust (no. 1) which bounds the
Wadi Queih Basin sequence at its top is cutting across the
felsite, up to 300 m stratigraphically above the base of
the felsite. As can be seen from the section and the map
(Figs. 3, 5), the thickness of the preserved felsite is
decreasing towards south so that no felsite is preserved in
the very south of the section, at the Hammamat window.
As a consequence, thrust number 1 is drawn as a flat in
the south, where it is probably following the top surface
of the Hammamat sequence. This is consistent with the
observation that the thrust is generally subparallel with the
Fig. 2. Geological and structural sketch map of the Pan-African basement rocks of the Eastern Desert of Egypt in the Quseir area. The lowest
structural level is occupied by gneissic rocks, the highest stratigraphic level is represented by the Hammamat Group sedimentary sequence.
Compiled from the geological maps of the Geological Survey of Egypt (1992 a, b) and Klitzsch et al. (1987), and sources listed in table 1.
For location see figure 1. Numbers in circles refer to locations in table 1. The Wadi Queih area is shown in detail on figure 3. Fold traces
trending broadly E-W are shown with continuous lines, NW-SE-oriented ones with dotted lines. The major Hammamat Group occurrences
occupy structural basins and the gneiss-cored domes are interpreted as structural domes, suggesting a dome-and-basin interference pattern.
This interference pattern is spatially related to and partly overprinted by the major strike-slip faults.
Gondwana Research, V. 8, No. 4, 2005
462
M.M. ABDEEN AND R.O. GREILING
bedding in the Hammamat sediments. Towards the north,
however, the thrust is ramping up into the felsite.
The early structures are overprinted by sinistral strikeslip faults (e.g., Um Kujura Wrench Fault, UKWF, Fig. 3)
and related folds in NW-SE direction. The system of strikeslip faults in the western part of the area is clearly the
NW tip of the UKWF, where displacement is distributed
between minor faults (Fig. 3), similar to a horse-tail
structure (e.g., Woodcock and Schubert, 1994). Together
with the Eastern Wrench Fault (EWF, Fig. 3), the UKWF
represents part of the NW tip of the orogen scale Najd
Fault System (Stern, 1985; Sultan et al., 1988). The UKWF
and EWF together with the associated folds indicate a
transpressional stress field which is distinctly different
from the earlier, NW-ward thrust-related stresses (Fig. 4).
Fault data on the strike-slip faults may not be sufficient to
determine the stress field related to this episode of
deformation, since a reactivation of the strike-slip faults
during extension cannot be excluded. As can be seen on
the map (Fig. 3), some of the strike-slip faults, for example
the EWF, are subparallel with younger normal faults
(e.g., EQBBF on Fig. 3), and, therefore, likely to show both
traces of strike-slip and normal faulting. As a consequence,
additional information on the associated folds is used here.
These folds show a consistent NW-SE trend on the map
(Fig. 3), parallel with the folds and related linear data
(fold axes, bedding-axial surface cleavage intersections)
documented in the field (Fig. 6). In combination with fault
data published by Abdeen and Warr (1998), the folds
indicate a stress field with the major principal axis in a
NE direction (Fig. 7). This direction, approximately normal
to the fold axis and fault trends, is then used for the
structural cross sections (Fig. 8).
Subsequent overprint by normal faults (e.g., faults
nos. 4, 5 on Fig. 5a) can be related to Cainozoic extension.
Although their displacement has been restored (see
below), they are not considered or quantified further here.
Section balancing and restoration
The detailed sections on the thrust units of Wadi Queih
Hammamat sediments and the surrounding rock units by
Abdeen and Warr (1998) provide an opportunity to
Fig. 3. Structural geological map of the Wadi Queih area, redrawn from Abdeen and Warr (1998). For location see figure 2. Sections A–A’ and B–B’ are
shown on figure 8, section C–C’ on figure 5.
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LATE PAN-AFRICAN COMPRESSIONAL DEFORMATION DURING GONDWANA ASSEMBLY, EGYPT
Fig. 4. Stress regime as interpreted from the early structural elements
shown on figure 3. See Abdeen and Warr (1998) for details.
quantify the deformation in this area (Figs. 5a, and 8
unrestored). Together with the data on strain/stress
geometry discussed above and compiled in figures 4 and 7,
they form the basis for the section balancing and
restoration presented here. Original sections and
restorations were drawn at a scale of 1:25.000. Figures 5
and 8 show a reduced, slightly simplified version. Since
the topographic relief is low, mostly less than a hundred
metres, the surface is drawn as flat. Earlier strain
determinations by Abdeen and Warr (1998) showed
considerable values of internal strain. However, they
determined strain only from rare, fine-grained, incompetent
beds (mudstones), which are not representative of the
Hammamat sequence as a whole. Even in these incompetent
beds a pervasive foliation is developed only at the axial
surfaces of some tight folds. Pebble strains in coarse clastic,
competent rocks are restricted to the vicinity of faults,
where pebbles are faulted. Elsewhere, for example in the
basal conglomerate at the northern margin of the Wadi
Queih Basin and away from the faults, pebbles do not
show any strain effects at all (our observation). Therefore,
the strain data of Abdeen and Warr (1998) are taken as
local, small-scale features, which are not relevant at the
map and section scales considered here. Following the
general procedures outlined by Woodward et al. (1989),
the youngest structural elements were restored first, which
are the Cainozoic normal faults in figures 5 and 8.
Subsequently, the elements of transpressional deformation
Gondwana Research, V. 8, No. 4, 2005
463
were restored (Fig. 8) and, finally, those of the first, thrustand-fold episode (Fig. 5).
Sections A–A’ and B–B’ (Fig. 5) were selected in order
to restore the transpressional deformation, since they are
approximately normal to the major principal stress
direction (compare Fig. 7). In the first step, the reverse
fault elements in ENE-WSW section, together with related
folds, (which are associated with later wrench faulting),
were restored. Late normal faults are related to Red Sea
rifting (e.g., Khalil and McClay, 2002) and are not
important here. The EWF, however, is related to the
Pan-African wrenching. Since no compression effects across
this fault have been observed in the field, no restoration
was necessary. The restoration, therefore, represents
exclusively the shortening across what is interpreted as a
positive (half-)flower structure, which branches from the
UKWF. For the fault block between the UKWF and the
EWF a shortening of 17% and 15% can be shown for
sections A–A’ and B–B’, respectively, using the line length
at the base of the Hammamat Group sediments (Fig. 8,
Table 2). The eroded and buried parts, respectively, can
be reliably reconstructed by down-plunge projection,
which is possible due to the gentle plunge of the structures
towards the SE (Figs. 3, 5a).
Finally, section C–C’ (Fig. 5) was used to restore the
earlier compressional strain. In order to exclude the effects
of strike-slip deformation, without deviating too much
from the principal strain direction, the section was drawn
in between the EWF and the UKWF, respectively. The
section is the most complete one for the thrusts in the
area, since it includes the fault-bounded window of
Hammamat Sediments in the SE of the area and a felsite
inlier farther NW. In addition, it is only mildly overprinted
by subsequent transpression and extension, respectively.
For the restoration the primary, unconformable contact
between the Dokhan volcanics and the overlying
Hammamat Sediments at the NNW end of the section
(C–C’, Fig. 5a) provided a reference, and the thrust contact
between Hammamat Sediments and the overlying
metavolcanics a datum. The results are shown in figure 5
with sequential restorations, starting from the present
section (C–C’, Fig. 5a). The faults are numbered according
to their relative age with 1 oldest and 5 youngest. The
youngest faults (4, 5) are extensional and oblique to the
section line (see map, Fig. 3). They are probably related
to Cainozoic, Red Sea extension and their displacement
is limited to a few tens of metres. Therefore, these faults
are simply restored within the section line (Fig. 5b).
Shortening is restored, starting with the out-of-sequence
thrust number 3 (Fig. 5c). Restoration of the folds proceeds
along the sole thrust number 2 between the Dokhan
Volcanics and the overlying Hammamat Sediments
(Fig. 5d). The folds have earlier been mapped in detail and
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M.M. ABDEEN AND R.O. GREILING
documented in a number of field photographs, sketches,
and cross-sections (Abdeen and Warr, 1998). Therefore,
their geometry can be reliably reconstructed, as shown
by a form line in the sections in figure 5 (a–c). Similar to
the procedure used in restoring the sections on figure 8
(above), the length of the form line at or closest to the
bottom of the Hammamat sequence was determined.
However, the felsite within the Hammamat Sediments has
not been restored since the displacement along its
boundaries cannot be quantified reliably. The contact may
be a thrust as is shown on the map (Fig. 3), but it may also
be an intrusive contact, which is only slightly overprinted.
Since the lateral extent of the fault-bounded felsite body
is limited, the displacement distance is regarded here as
small. As the last step, the thrust fault number 1 between
the Hammamat Sediments and the overlying metavolcanic
rocks is restored (Fig. 5e). The section restoration indicates
25% of shortening in the NNW-SSE direction (Fig. 5,
Table 2). It should be noted, however, that this value is
only a minimum figure. As is pointed out on the restored
B–B’
section (Fig. 5e), there are two areas, where section is missing.
One area is that of the Hammamat window, where material
was removed by erosion in the hangingwall of the out-ofsequence thrust number 3. The other area at the SSE margin
of the section is unexposed so that the primary basin
margin is buried and the primary basin width is unknown.
Therefore, the transport distance of the metavolcanic thrust
unit over the Hammamat Group sediments cannot be
quantified any further. However, considering the difference
in metamorphic grade from greenschist grade in the
metavolcanic rocks to sub-greenschist-grade in the
Hammamat Sediments (Abdeen and Warr, 1998), the
displacement along the low angle thrust would be substantial.
Other Hammamat Group Basins and Regional
Structure
Following up on the fundamental studies by Akaad and
El Ramly (1958), Akaad and Noweir (1969), and
Grothaus et al. (1979) on the distribution and sedimentary
A–A’
Fig. 5. Section C–C’ showing geometry of structures related to early compression. a: present section, b–e: sequentially restored sections. See figure 3
for location. Thrusts are numbered according to their relative age, with 1 oldest and 5 youngest. See text for further discussions.
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LATE PAN-AFRICAN COMPRESSIONAL DEFORMATION DURING GONDWANA ASSEMBLY, EGYPT
Fig. 6. Stereonet (lower hemisphere, equal area projection) showing
elements of a fold related to the late stage of transpressional
deformation. Bedding data, shown as poles (dots) show a great
circle distribution, defining a fold with an axial trend of c. 130°,
consistent with related lineation data (contoured, N = 8). For
location see figure 3.
environment of the Hammamat Group basins, modern
studies cover now many of the late-orogenic sedimentary
deposits (see reviews by Garfunkel, 1999; Blasband et al.,
2000, and references in Table 1). Although most of these
studies discuss some regional aspects, there is not yet any
comprehensive study on the late Pan-African deformational
pattern at the scale of the orogen. Therefore, it is
attempted here to relate the structural results of the Wadi
Queih area to the adjacent areas of the Eastern Desert, the
Central Eastern Desert (CED) in order to investigate the
regional-scale structural pattern and to test whether the
post-Hammamat structural evolution seen at Wadi Queih
is representative at the regional scale.
Regional post-Hammamat structures
As a first step, the structures are summarized in this
chapter, whilst their genetic implications and tectonic
significance are discussed in the following chapters.
Table 1 gives a compilation of the most important postdepositional structural events and related features
affecting the Hammamat Basins in the region. The basins
and their structures are broadly grouped from west to east
(Fig. 2). Although younger structures overprinted the
regional pattern, careful inspection shows that the general
strike of the Hammamat Group sequences in the QuseirGondwana Research, V. 8, No. 4, 2005
465
Hammamat region is broadly ENE-WSW. This is clear from
Wadi Queih, which was discussed above, and is also clear
from the maps of Wadi Kareim by Fritz and Messner
(1999). Towards W, at Wadi Zeidoun and Wadi Meesar,
the beds are, in general, gently dipping towards northerly
directions (Osman, 1996). The situation in Wadi Hammamat
is more complex, due to local, NW-SE trending folds and
late tectonic granite intrusions (Fowler, 2001; Fowler and
Osman, 2001, and references therein). However, at a
regional scale, the strike of the northern margin of the
Hammamat Group sediments is broadly E–W, with minor
fold structures plunging SE (Fowler and Osman, 2001).
As a consequence, the major Hammamat exposures can
be seen as representing the cores of a set of broadly
ENE-WSW oriented synclinal structures separated by
anticlinal areas. This set of folds was subsequently
overprinted by NW-SE trending strike-slip faults and
associated transpression that produced some NW-SE to
NNW-SE oriented folds (Fig. 2). The resulting interference
pattern can be traced across the whole area between Wadi
Hammamat in the west and Quseir in the east. Although
there are minor differences in the orientation of the
relevant structures, all the published data and the new
data presented here are consistent and point to a regional
significance of these structures. Based on these spatial
correlations of structural elements, it is now possible to
relate the structural evolution of the different areas with
some confidence.
Regional structural evolution
Extension during basin formation is not well constrained
but appears to have been in a general N-S to NW-SE
direction (see Table 1). Subsequently, there is a compressional
structural event with σ1 broadly NNW-SSE, similar to the
situation in Wadi Qheih (Fig. 4). Thrusts and folds of this
early compressional stage are overprinted by complex
structural systems associated with a second compressional
event. These second generation structures include largescale wrench faults (broadly NW-SE) with associated
positive (half-)flower structures, and folds with NW-SE
to NNW-SSE-oriented fold traces. As in the Wadi Queih
area a change in the direction of compression from
NNW-SSE (Fig. 4) to NE-SW (Fig. 7) can be interpreted.
This change in σ1 direction may also be accompanied by
a change in σ3 direction from subvertical to subhorizontal,
with a NNW-SSE direction, on the basis of the formation
of strike slip faults (σ2 vertical; compare Fig. 7). This σ3
direction is broadly parallel with the late extension
direction as observed, for example, at Um Esh (Fowler
and El Kalioubi, 2004), the Meatiq and El Sibai domes,
and the Fawakhir granite (Loizenbauer and Neumayr,
1996). As a whole, the local structural studies across the
CED show a remarkably consistent orientation of early
466
M.M. ABDEEN AND R.O. GREILING
post-Hammamat folds and thrusts indicating NNW-SSE
compression, and subsequent folds oriented NNW-SSE,
which are associated with extension parallel to their fold
axial direction and with NW-SE-oriented sinistral wrench
faults (Table 1). However, whilst the geometry of these
structures and their relative time-sequence appears to be
very similar, their absolute timing may be less consistent,
as is discussed below.
Discussion
The Wadi Queih area
The Hammamat Group sediments exposed in the Wadi
Queih area were deposited in a basin with a broadly E-Wtrending northern margin. Basal conglomerates occur only
in the NE part of the basin, along the exposed primary
margin. This supports the model of NE-SW to E-W
elongation directions of the Hammamat Basins proposed
by Stern et al. (1988). The sediments, together with the
other rock units in the Wadi Queih area were subjected to
late Pan-African folding and thrusting processes as
indicated by the presence of S and SE dipping low angle
thrusts and NNW verging folds (Abdeen et al., 1992; Abdeen
and Warr, 1998; Greiling et al., 1994). Subsequently, both
the Hammamat sediments and the Pan-African thrust units
were deformed by NW-SE oriented sinistral strike-slip
faults that belong to the Najd Fault System in the CED
Fig. 7. Stress regime as interpreted from the late, strike-slip and
transpressional structural elements shown on figures 3 and 6,
and fault data from Abdeen and Warr (1998).
(Stern, 1985). These faults are associated with sub-parallel
high angle reverse faults that form a positive (half-)flower
structure. They are interpreted to be a result of transpression
following the Pan-African thrusting (Abdeen et al., 1992;
Abdeen and Warr, 1998). Both of these structural epidsodes
clearly post-date basin formation of Hammamat Group
sediments, which until recently were presumed to represent
the latest features of Pan-African orogeny. Section
restorations show a modest amount of compression during
both the first and second post-Hammamat deformation
phases of >25% and 15–17%, respectively (Table 2,
Figs. 5, 8). The restorations quantify the latest stages of a
shortening deformation and do not take into consideration
any earlier extension, which may have been associated
with basin formation. However, they confirm that the
Pan-African orogeny at Wadi Queih did not end with latetectonic extension and collapse but with overall shortening.
Late orogenic basin formation and deformation in the
Central Eastern Desert (CED)
The molasse type, Hammamat Group sediments
comprise thick, epiclastic successions deposited by alluvial
fan-braided stream systems in intermontane basins
(Grothaus et al., 1979), and in down-faulted grabens that
were trending NE-SW to E-W (Stern et al., 1988). Tectonic
overprint of the basins strarted with granite intrusions
at c. 595 Ma ago (Ries et al., 1983) and lasted until
c. 580 Ma ago (Loizenbauer et al., 2001, and references
therein). As is evident from the traces of major structures,
broadly E-W-trending, post Hammamat folds cover the
whole of the area, albeit with varying intensity (Fig. 2).
This is also the case for NW-SE-trending folds and spatially
related strike-slip faults. In addition, a number of studies
showed that the time sequence may also be the same over
the region (Table 2). In particular, the structural sequence
in the Wadi Hammamat type area and adjacent areas
(Fig. 2, locations 1–4) has been worked out by several
independent groups, which all agree on a postHammamat-sediment structural sequence of ENE-WSW
folds and thrusts overprinted by NNW-SSE-oriented folds,
which are mostly associated with sinistral strike-slip faults
in NW-SE direction (e.g., Mostafa and Bakhit, 1988;
de Wall et al., 1998; Fowler and Osman, 2001; Fowler
and El Kalioubi, 2004). However, there may also be local
examples of a more complex or a diachronous evolution.
A deformation phase with NW-SE extension at Fawakhir
(Loizenbauer and Neumayr, 1996) may be related with
the early extension during basin formation or,
alternatively, with the late phase of NE-SW compression.
The recorded extensional joints strike ENE-WSW.
This strike direction is consistent with the regional
σ1 direction interpreted here (Fig. 7). Therefore, these
extensional joints do not necessarily indicate a dominant
Gondwana Research, V. 8, No. 4, 2005
LATE PAN-AFRICAN COMPRESSIONAL DEFORMATION DURING GONDWANA ASSEMBLY, EGYPT
component of gravitational deformation, i.e., vertical
σ1 as envisaged by Loizenbauer and Neumayr (1996), but
are interpreted here as related to the late stage of compression
with a subhorizontal σ1. This late phase of compression
has been shown to be associated with NW-SE extension,
normal to the shortening direction, by Fowler and
El Kalioubi (2004).
In the Um Esh area (location 4, Fig. 2), subhorizontal
folds with NW-SE stretching lineations (Fowler and
El Kalioubi, 2004) have been correlated here with the late
shortening episode (Table 1). However, this is in contrast
with the interpretation of Fowler and El Kalioubi (2004)
that this episode is associated with gravitational collapse.
Further work will have to show, whether the simple
correlation in table 1 is correct, or whether an additional
episode of post-Hammamat deformation can be verified.
This may also be true for the adjacent Gabal Meatiq area
(location 5), where Loizenbauer et al. (2001) documented
a tectonic history lasting for more than 200 Ma. These
authors show only two deformational events after 620 Ma
ago. Whilst the early one of N-S extension may be
correlated with the basin formation, the second one is
similar to the late stage of transpression. However, there
appears to be no trace of post 620 Ma (post-Hammamat?)
age NNW-SSE compression. Furthermore, there is not yet
conclusive evidence, whether the Meatiq dome originated
exclusively by gravitative rise of buoyant gneissic material
as suggested by Fritz et al. (1996) and Loizenbauer et al.
(2001), or exclusively as a dome in a compressional
structural interference pattern (Fig. 2). Since these two
extremes are not mutually exclusive, it may well be that
these two mechanisms acted together.
In the area towards south, Fritz and Messner (1999)
argued that the Wadi Kareim Basin (location 6, Fig. 2,
Table 1) evolved in two steps. The early step was basin
subsidence that was magmatically-induced when extraction
of magmas from the lower crust led to compensating
downward movement of cold, dense material. The second
step was the modification of the basin geometry by strikeslip deformation (belonging to the Najd Fault System).
The structural overprint appears to be more complex,
when maps and sections from the Wadi Kareim Basin of
Fritz and Messner (1999) are considered. There, an
approximately E–W oriented syncline is obvious. This
syncline is interpreted here as belonging to the system of
early post-Hammamat folds which developed mainly after
deposition by horizontal compressional forces, and prior
to the strike-slip Najd Fault-related deformation.
A comparable structural sequence has also been
observed SE of Wadi Kareim in the Sibai Gneissic Complex
and at Umm Gheig (locations 7; 8; Ibrahim and Cosgrove,
2001). However, there, the directions of thrusts (WNW
strike) and refolding folds (WNW-ESE) are 20° different,
Gondwana Research, V. 8, No. 4, 2005
467
appearing to be rotated from the normal NW-SE directions
in the other areas by anti-clockwise rotation. Such a
rotation is consistent with the sinistral movement along
the Najd Fault System (Stern, 1985). Therefore, the
difference in the orientation of the structures in the Um
Gheig area is interpreted here to be an effect of a latest
increment of strike-slip along the Najd Faults. In that case,
the wrench faulting has been substantial, in contrast to
areas in the north, where the tips of wrench faults can be
observed (Wadi Queih), or no wrenching at all (Wadi
Hammamat, Atalla Zone). As a consequence, the
strike-slip component appears to be subordinate in the
NW (e.g., Wadi Hammamat, Atalla zone, de Wall et al.,
1998), and more prominent towards SE (e.g., Um Esh,
Fawakhir, Fowler and El Kalioubi, 2004; Loizenbauer and
Neumayr 1996), and increasing even more farther towards
SE, at El Sibai and Um Gheig (Kamal El Din, 1993; Ibrahim
and Cosgrove, 2001; Bregar et al., 2002). A variation in
strain intensity is also supported by the available
quantitative data. 15–17% NE-SW directed shortening are
documented in the Wadi Queih area as accompanying the
transpression (Fig. 5, Table 2). A section across the MeatiqUm Esh area shows c. 20% of shortening in the same
direction (Fowler and El Kalioubi, 2004; Fowler, pers.
comm. 2005).
Such strain vatiations and apparent disagreement as
to the importance of strike-slip faulting can be resolved
by the observation that the CED as a whole covers the
NW-tip of the regional scale strike-slip faults (see Fig. 2).
This information also solves the volume problem at the
northern end of the Najd Fault System as discussed by
Stern (1985). Displacement is simply dying out
northwards with the large-scale faults fanning out into
minor faults and associated folds. Together with the earlier
compressional event, the Najd Fault episode represents
the latest stages of Pan-African orogenic deformation.
At a regional scale (Fig. 2), these two post-Hammamat
compressional events produced an interference pattern
with domes and basins. The structural basins are invariably
cored by Hammamat sediments. It has to be noted that
some of the basinal sediments are eroded and the basins
described here may once have been contiguous, for
example the Wadi Hammamat and Wadi Zeidun and Wadi
Meesar Basins (see Fig. 2).
Late orogenic structural evolution at a regional scale
Earlier, Greiling et al. (1994) and Blasband et al. (2000)
referred the basin formation to the phase 4 of the 5 phase
tectonic evolution of mountain belts proposed by Dewey
(1988). This phase comprises orogenic collapse and
formation of extensional basins within the orogen and
along its margins and leads to cooling and a stabilization
of the newly formed lithosphere (see discussion by
468
M.M. ABDEEN AND R.O. GREILING
Fig. 8. Sections A–A’ and B–B’ across late strike-slip faults, related reverse faults and folds, which, together, form a positive flower structure.
The sinistral sense of strike-slip faults is indicated by conventional, round symbols. See figure 3 for location. Below each section a restoration
of the NE part is shown.
Garfunkel, 1999). In spite of wide-spread magmatism, the
illite crystallinity data from the Hammamat Basins
show that there was no pervasive heating throughout the
crust. As can be seen from the available P and T data
(Osman et al., 1993; Warr et al., 1999; Abdeen and Warr,
1998; Loizenbauer et al., 2001), subsequent erosion of
the orogen prior to early Palaeozoic cover sedimentation
was limited to a few kilometers. Apparently, earlier
thinning, which ended with the formation of the
Hammamat Basins had produced a crust of approximately
‘‘normal’’ continental thickness, which was relatively stable
gravitationally, cooled relatively quickly and became
strong. However, until the crust was completely
consolidated, it suffered at least two episodes of (limited)
compressional deformation with σ1 in (sub-) horizontal
orientations.
Conclusions
The Hammamat Group was deposited in intramontane
basins formed due to N-S to NW-SE directed extension,
differential uplift, and erosion of the Pan-African orogen,
which provided clastic sediments to the basins.
A comparison of post-Hammamat Group structural
features in the basement areas west of Quseir and
including the type area at Wadi Hammamat, shows a
number of similarities. A NNW-SSE-oriented compression
prevailed after the deposition of the Hammamat sediments.
This is documented by the presence of NW-verging folds
and SE-dipping thrusts that were refolded and thrusted
in the same direction. Restoration of a NNW-SSE oriented
balanced section across Wadi Queih indicates more than
25% shortening. Transpressional wrenching related to the
Najd Fault System followed this stage. The wrenching
produced NW-SE sinistral faults associated with positive
(half-)flower structures that comprise NE verging folds
and SW-dipping thrusts. Section restoration across these
late structures in the Wadi Queih area indicates 15–17%
shortening in the NE-SW direction. The Najd Fault System
splays into a horsetail structure in the Wadi Queih area
and loses displacement towards N and NW. At the Wadi
Hammamat type area and at the Atalla Zone, wrench
deformation becomes insignificant and shows that the
Najd Fault System dies out also towards west. These strain
variations are also supported by the available quantitative
data. At a regional scale, the two post-Hammamat
compressional phases produced an interference pattern
with domes and basins.
The present study shows a distinct space and time
relationship between deposition of Hammamat Group latePan-African clastic sediments and late stages of Najd
System wrench faulting: Hammamat deposition is
followed by two episodes of compression, the later of the
two being related to Najd Fault transpression. Therefore,
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LATE PAN-AFRICAN COMPRESSIONAL DEFORMATION DURING GONDWANA ASSEMBLY, EGYPT
the Hammamat Sediments do not represent the latest
tectonic feature of the Pan-African orogeny in the ANS. It
is speculated that extension and (Hammamat) basin
formation was sufficiently effective so that it reduced the
thickness of the orogenic lithosphere until it became
gravitationally stable. Instead of further gravitational
deformation, the latest orogenic episodes were the two
successive phases of compression and transpression,
respectively.
Acknowledgments
This work is the result of the cooperation between the
National Authority for Remote Sensing and Space
Sciences, Cairo, Egypt, and Geologisch-Paläontologisches
Institut (GPI), Ruprecht-Karls-Universität Heidelberg. The
first author visited GPI as a visiting scientist and lecturer,
funded successively by Deutsche Forschungsgemeinschaft
(DFG) and Ruprecht-Karls-University. The authors thank
these institutions, as well as Nahed Abdelsalam Farag for
her general support, and G. Froelich and E. Hofmann for
computer assistance. Field data for figure 6 were collected
during the 2004 Marsa Um Gheig field workshop by
EGSMA, Cairo, and GPI. We thank Kathrin Abraham,
Evelyn Böhm, Frank Dietze, René Grobe, Maren Kahl,
Friedemann Maaß, Tina Pelzer, Marc Petras, Sebastian
Pfeil, Lena Schilling, Manuel Sehrt, and Henrik Wild, for
their support. Reviewers Profs. H. de Wall and A.-R. Fowler
are thanked for their careful reviews and detailed
comments and suggestions for improvement.
References
Abdeen, M.M. (2003) Tectonic history of the Pan-African orogeny
in Um Gheig area, central Eastern Desert, Egypt. J. Geol.
Soc. Egypt. v. 47, pp. 239-254.
Abdeen, M.M. and Warr, L.N. (1998) Late orogenic basin
evolution, deformation and metamorphism in the PanAfrican basement, Wadi Queih, Eastern Desert of Egypt.
Forschungszentrum Jülich, Sci. Series Int. Bureau v. 42, 272p.
Abdeen, M.M., Dardir, A.A. and Greiling, R.O. (1991)
Hammamat pebbles in Felsite at Wadi Queih, north of Quseir,
Eastern Desert of Egypt. Annals Geol. Surv. Egypt, v. 17,
pp. 73-75.
Abdeen, M.M., Dardir, A.A. and Greiling, R.O. (1992) Geological
and structural evolution of the Wadi Queih Area (N Quseir),
Pan-African basement of the Eastern Desert of Egypt. Zbl
Geol Paläont, Teil I, v. 1992, pp. 2653-2659.
Abdeen, M.M., Dardir, A.A. and Greiling, R.O. (1997) Rain drop
prints mud crack polygons and pebbles as strain markers in
a Pan-African molasse basin, Wadi Queih, Arabian Desert,
Egypt. Annals Geol. Surv. Egypt, v. 20, pp. 185-191
Abdelsalam, M.G., Stern, R.J., Copeland, P., Elfaki, E.M.,
Elhur, B. and Ibrahim, F.M. (1998) The Neoproterozoic Keraf
Suture in NE Sudan: sinistral transpression along the eastern
margin of West Gondwana. J. Geol. v. 106, pp. 133-148.
Gondwana Research, V. 8, No. 4, 2005
469
Akaad, M.K. and Noweir, A.M. (1969) Lithostratigraphy of the
Hammamat Um Seleimat district, Eastern Desert, Egypt.
Nature, v. 223, pp. 284-285.
Akaad, M.K. and El Ramly, M.F. (1958) Seven new occurrences
of the Igla Formation in the Eastern Desert of Egypt. Geol.
Surv. Mineral Res. Dept., Paper 3, pp. 1-37.
Bennett, J.D. and Mosley, P.N. (1987) Tiered-tectonics and
evolution, Eastern Desert and Sinai, Egypt. In: Matheis, G.
and Schandelmeier, H. (Eds.), Current Research in African
Earth Sciences, Balkema, Rotterdam, pp. 79-82.
Blasband, B., White P., Brooijmans, H., de Boorder, H. and
Visser, W. (2000) Late Proterozoic extensional collapse in
the Arabian-Nubian Shield. J. Geol. Soc., London, v. 157,
pp. 615-628.
Bregar, M., Bauernhofer, A., Pelz, K., Kloetzli, U., Fritz, H. and
Neumayr, P. (2002) A late Neoproterozoic magmatic core
complex in the Eastern Desert of Egypt: emplacement of
granitoids in a wrench-tectonic setting. Precambrian Res.,
v. 118, pp. 59-82.
BRGM (Ed.) (2004) Géologie et principaux gisements de
l’Afrique, 1:10,000,000. Orléans.
Burke, K. and Sengör, C. (1986) Tectonic escape in the
evolution of the continental crust. AGU Geodynam. Ser.,
v. 14, pp. 41-53.
de Wall, H., Warr, L.N., Kamal El-Din, G.M. and Greiling, R.O.
(1998) Spätorogene Entwicklung an steilen
Deformationszonen– pure shear oder simple shear?
Panafrikanische Atalla Zone, Eastern Desert, Ägypten.
Freiberger Forschungsheft v. C 471, pp. 55-57.
Dewey, J.F. (1988) Extensional collapse of orogens. Tectonics,
v. 7, pp. 1123-1139.
El-Gaby, S., List, F.K. and Tehrani (1988) Geology, evolution
and metallogenesis of the Pan-African belt in Egypt.
In: El-Gaby, S. and Greiling, R.O. (Eds.), The Pan-African
belt of NE Africa and adjacent areas. Earth Evolution Sciences
Vieweg, Wiesbaden, pp. 17-68.
El-Taky, M.M. (1988) Geology of Wadi Queih area, Eastern
Desert, Egypt. M.Sc. thesis. Fac. Sci. Qena, Assiut Univ. Egypt,
167p.
Fowler, T.J. (2001) Pan-African granite emplacement
mechanisms in the Eastern Desert, Egypt. J. Afri. Earth Sci.,
v. 32, pp. 61-86.
Fowler, T.J. and Osman, A.F. (2001) Gneiss-cored interference
dome associated with two phases of late Pan-African
thrusting in the Central Eastern Desert, Egypt. Precambrian
Res. v. 108, pp. 17-43.
Fowler, A.-R. and El Kalioubi, B. (2004) Gravitational collapse
origin of shear zones, foliations and linear structures in the
Neoproterozoic cover nappes, Eastern Desert, Egypt. J. Afri.
Earth Sci., v. 38, pp. 23-40.
Fritz, H. and Messner, M. (1999) Intramontane basin formation
during oblique convergence in the Eastern Desert of Egypt:
magmatically versus tectonically induced subsidence.
Tectonophys., v. 315, pp. 145-162.
Fritz, H., Wallbrecher, E., Khudeir, A.A., Abu el Ela, F. and
Dallmeyer, D.R. (1996) Formation of Neoproterozoic
metamorphic core complexes during oblique convergence
(Eastern Desert, Egypt.). J. Afri. Earth Sci., v. 23, pp. 311-329.
Fritz, H., Dallmeyer, D.R., Wallbrecher, E., Loizenbauer, J.,
Hoinkes, G., Neumayr, P. and Khudeir, A.A. (2002)
Neoproterozoic tectono-thermal evolution of Central Eastern
470
M.M. ABDEEN AND R.O. GREILING
Desert, Egypt: a slow velocity tectonic process of core complex
exhumation. J. Afri. Earth Sci., v. 34, pp. 137-155.
Garfunkel, Z. (1999) History and palaeogeography during the
Pan-African orogen to stable platform transition: reappreaisal
of the evidence from the Elat area and the northern ArabianNubian Shield. J. Earth Sci. Israel, v. 48, pp. 135-157.
Gass, I.G. (1981) Pan-African (Upper Proterozoic) plate tectonics
of the Arabian-Nubian shield. In: Kröner, A. (Ed.), Precambrian
plate tectonics, developments in Precambrian geology.
Elsevier, Amsterdam, pp. 387-405.
Geological Survey of Egypt (1992a) Geologic map of Wadi Al
Barramiyah Quadrangle, Egypt. Scale 1:250 000. Cairo,
Egypt.
Geological Survey of Egypt (1992b) Geologic map of Al Qusayr
Quadrangle, Egypt. Scale 1.250.000. Cairo, Egypt.
Greiling, R.O., Abdeen, M.M., Dardir, A.A., El Akhal, H.,
El Ramly, M.F., Kamal El Din, G.M., Osman, A.F., Rashwan,
A.A., Rice, A.H.N. and Sadek, M.F. (1994) A structural
synthesis of the Proterozoic Arabian - Nubian Shield in Egypt.
Geol. Rundsch., v. 83, pp. 484-501.
Grothaus, B., Eppler, D. and Ehrlich, R. (1979) Depositional
environment and structural implication of the Hammamat
Formation, Egypt. Ann. Geol. Surv. Egypt, v. 9, pp. 564-590.
Hamad, S. (2003) Geologische Kartierung des Gebietes Wadi
Umm Gheig, östliche (arabische) Wüste von Ägypten. Geol.
Paläontol. Instit., Ruprecht-Karls-Universität Heidelberg, 39p.
Hassan, M.A. and Hashad, A.H. (1990) Precambrian of Egypt.
In: Said, R (Ed.), The geology of Egypt. Balkema, Rotterdam,
pp. 201-245.
Hermina, M., Klitzsch, E. and List, F.K. (1989) Stratigraphic
lexicon and explanatory notes to the geological map of Egypt.
1:500,000 Conoco Inc, Cairo, 264p.
Hume, W.F. (1934) Geology of Egypt. Vol. 2, part 1: The
fundamental Pre-Cambrian rocks of Egypt and the Sudan,
their distribution, age and character: the metamorphic rocks.
Survey of Egypt (Government Press), Cairo, pp. 1-300.
Hume, W.F. (1937) Geology of Egypt. Volume 2, part 3: The
fundamental Pre-Cambrian rocks of Egypt and the Sudan,
their distribution, age and character: the minerals of
economic value associated with the intrusive Precambrian
igneous rocks. Survey of Egypt (Government Press), Cairo,
pp. 689-990.
Ibrahim, S. and Cosgrove, J. (2001) Structural and tectonic
evolution of the Umm Gheig/El-Shush region, central Eastern
Desert of Egypt. J. Afri. Earth Sci., v. 33, pp. 199-209.
Johnson, P.R. and Woldehaimanot, B. (2003) Development of
the Arabian-Nubian Shield: perspectives on accretion and
deformation in the northern East African Orogen and the
assembly of Gondwana. Geol. Soc. London Spec. Pub.,
v. 206, pp. 289-325.
Khalil, S.M. and McClay, K.R. (2002): Extensional fault-related
folding, northwestern Red Sea, Egypt. J. Struct. Geol., v. 24,
pp. 743-762.
Kamal El Din, G.M. (1993) Geochemistry and tectonic significance
of the Pan-African El Sibai Window, Central Eastern Desert,
Egypt. Sci. Series Int. Bureau, v. 19, pp. 1-154.
Kamal El Din, G.M., Khudeir, A.A. and Greiling, R.O. (1992)
Tectonic evolution of a Pan-African gneiss culmination, Gabal
El Sibai area, Central Eastern Desert, Egypt. Zbl. Geol.
Paläont. Teil 1, v. 1991, pp. 2637-2640.
Klitzsch, E., List, F.K. and Pöhlmann, G. (1987) Geological map
or Egypt. 1:500,000. Conoco Inc., Cairo.
Kröner, A. (1985) Ophiolites and the evolution of tectonic boundaries
in the late Proterozoic Arabian-Nubian Shield of Northeast
Africa and Arabia. Precambrian Res., v. 27, pp. 277-300.
Kröner, A., Greiling, R.O., Reischmann, T., Hussein, I.M.,
Stern, R.J., Krüger, J., Dürr, S. and Zimmer, M. (1987)
Pan-African crustal evolution in the Nubian segment of
Northeast Africa. Amer. Geophys Union, Geodyn. Ser., v. 17,
pp. 235-257.
Loizenbauer, J. and Neumayr, P. (1996) Structural controls on
the formation of the Fawakhir gold mine, El-Sid – Eastern
Desert, Egypt: tectonic and fluid inclusion evidence. Proc.
Geol. Surv. Egypt Cent. Conf., pp. 477-488.
Loizenbauer, J., Wallbrecher, E. and Fritz, H. (1999) Formation
and structural evolution of the Meatiq Metamorphic Core
Complex during post-Rodinian tectonics – a reconstruction
by the use of fluid inclusion studies, structural geology and
age dating. In: de Wall, H. and Greiling, R.O. (Eds.), Aspects
of Pan-African tectonics. Schriften Forschungszentrum.
Bilateral Seminars Int. Bureau., v. 32, pp. 143-148.
Loizenbauer, J., Wallbrecher, E., Fritz, H., Neumayr, P.,
Khudeir, A.A. and Kloetzli, U. (2001) Structural geology,
single zircon ages and fluid inclusion studies of the Meatiq
metamorphic core complex: Implications for Neoproteroic
tectonics in the Eastern Desert of Egypt. Precambrian Res.,
v. 110, pp. 357-383.
Mostafa, M.E. and Bakhit, F.S. (1988) Analysis of deformed
pebbles and the origin of uranium-mineralized fractures
around Wadi Atalla, Central Eastern Desert, Egypt. M.E.R.C.
Ain Shams Univ., Earth Sci. Ser., v. 2, pp. 116-124.
O’Connor, E.A. (1996) One hundred years of geological
partnership: British-Egyptian geoscientific collaboration,
1986-1996. British Geol. Surv., Keyworth.
Osman, A.F. (1996) Geological, geochemical and structural
studies of the Pan-African basement rocks, Wadi Zeidun area,
Central Eastern Desert, Egypt. Scientific series of the Int.
Bureau, Forschungszentrum Jülich, v. 39, 262p.
Osman, A.F., Greiling, R.O., Warr, L.N., Hilmy, M.E., Ragab, A.I.
and El Ramly, M.F. (1993) Distinction of different syn- and
late orogenic Pan-African sedimentary sequences by
metamorphic grade and illite crystallinity (W Zeidun,
Cental Eastern Desert, Egypt). In: Thorweihe, U. and
Schandelmeier, H. (Eds.), Geoscientific Res. in NE Africa.
Balkema, Rotterdam, pp. 21-25.
Rice, A.H.N., Osman, A.F., Sadek, M.F., Ragab, A.I. and
Abdeen, M.M. (1993) Preliminary comparison of sixlateto post-Pan-African molasse basins, E. Desert, Egypt.
In: Thorweihe, U. and Schandelmeier, H. (Eds.), Geoscientific
research in Northeast Africa. Balkema, pp. 41-45.
Ries, A.C., Shackleton, R.M., Graham, R.H. and Fitches, W.R.
(1983) Pan-African structures, ophiolites and mélange in
the Eastern Desert of Egypt: a traverse at 26° N. J. Geol. Soc.
London, v. 140, pp. 75-95.
Said, R. (1990) The geology of Egypt. Bakema, Rotterdam, 734p.
Shackleton, R.M. (1986) Precambrian collision tectonics in
Africa. In: Coward, M.P. and Ries, A.C. (Eds.), Collision
tectonics. Geol. Soc. London, Spec. Pub. v. 19, pp. 329-349.
Shackleton, R.M., Ries, A.C., Graham, R.H. and Fitches, W.R.
(1980) Late Precambrian ophiolitic mélange in the Eastern
Desert of Egypt. Nature, v. 285, pp. 472-474.
Gondwana Research, V. 8, No. 4, 2005
LATE PAN-AFRICAN COMPRESSIONAL DEFORMATION DURING GONDWANA ASSEMBLY, EGYPT
Smith, M., O’Connor, E. and Nasr, B.B. (1999) Transpressional
flower structures and escape tectonics: a new look at the
Pan-African collision in the Eastern Desert, Egypt. In: de
Wall, H. and Greiling, R.O. (Eds.), Aspects of Pan-African
tectonics, Int. Cooperation, Bilateral Seminars Int. Bureau,
Germany: Forschungszentrum Jülich, v. 32, pp. 81-82.
Stern, R.J. (1985) The Najd fault system, Saudi Arabia and Egypt:
a Late Precambrian rift system? Tectonics, v. 4, pp. 497-511
Stern, R.J. (1994) Arc assembly and continental collision in the
Neoproterozoic East African Orogen. Ann. Rev. Earth Planet
Sci., v. 22, pp. 319-351.
Stern, R.J., Sellers, G. and Gottfried, D. (1988) Bimodal dyke
swarms in the NE Desert of Egypt: significance for the origin
of Late Precambrian ‘‘A-type’’ granites northern Afro-Arabia.
In: El-Gaby, S. and Greiling, R.O. (Eds.) the Pan-African Belt
of NE Africa and adjacent areas. Vieweg, Braunschweig,
pp. 147-179.
Sturchio, N.C., Sultan, M. and Batiza, R. (1983) Geology and
origin of Meatiq dome, Egypt: a Precambrian metamorphic
core complex? Geology, v. 11, pp. 72-76
Sultan, M., Arvidson, R.E., Duncan, I.J., Stern, R.J. and El
Kaliouby, B. (1988) Extension of the Najd Shear System from
Gondwana Research, V. 8, No. 4, 2005
471
Saudi Arabia to the CED of Egypt based on integrated field
and Landsat observations. Tectonics, v. 7, pp. 1291-1306
Unrug, R. (1997) Rodinia to Gondwana: the geodynamic map of
Gondwana supercontinent assembly. GSA Today. v. 7, pp. 1-6.
Warr, L.N., Greiling, R.O., Rice, A.H.N., Abdeen, M.M.,
Sadek, M.F., Kamal El Din, G.M. and Osman, A.F. (1999)
Low temperature metamorphism in the Hammamat
Basins of the Eastern Desert of Egypt. In: de Wall, H. and
Greiling, R.O. (Eds.), Aspects of Pan-African tectonics.
Forschungszentrum Jülich, Int. Cooperation, Bilateral
Seminars of the Int. Bureau v. 32, pp. 167-171.
Willis, K.M., Stern, R.J. and Clauer, N. (1988) Age and
geochemistry of Late Precambrian sediments of the
Hammamat Series from the NE Desert of Egypt. Precambrian
Res., v. 42, pp. 173-187.
Woodcock, N.H. and Schubert, C. (1994) Continental strikeslip tectonics. In: Hancock, P.L. (Ed.), Continental deformation.
Oxford, Pergamon Press, pp. 251-263.
Woodward, N.B., Boyer, S.E. and Suppe, J. (1989) Balanced
geological cross-sections: an essential technique in Geological
research and exploration. Amer. Geophys. Union, Short
Course Geology, v. 6, 132p.