Quaternary Science Reviews 21 (2002) 853–869
Event stratigraphy, paleoenvironment and chronology
of SE Arabian deserts
K.W. Glenniea,*, A.K. Singhvib
a
Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen AB9 2UE, UK
b
Earth Science Division, Physical Research Laboratory, Ahmedabad 380 009, India
Received 4 January 2000; accepted 10 October 2001
Abstract
The geological record of the SE Arabian desert is exhibited in a variety of geomorphic features and their characteristic sediments,
ranging from alluvial fans to inland and coastal dunes and sabkhas. Together, they suggest a large range of environmental and
climatic variability between periods of relative aridity and humidity. Sedimentary events in the Emirates appear to correlate broadly
with high-latitude glaciations, which affected both the Shamal winds and the extent of exposure of the Arabian Gulf. In general, the
aeolian sands in the Rub al Khali responded to glacial events as a consequence of exposure of the floor of the Arabian Gulf. During
glacials when Global sea level was low, quartz sands from across the exposed floor of the Arabian Gulf were transported by the
Shamal winds south-eastwards to the Emirates and then south to the Rub al Khali. The supply of Shamal-transported sand from the
floor of the Arabian Gulf was cut off by high stands of sea level during interglacial periods. The new coastal dunes (‘miliolite’), rich
in foraminifera and other cement-assisting calcareous shell fragments, were deflated down to the water table as their sand was
transported further to the south, leading to the creation of coastal sabkhas. Studies on aeolianites and the lacustrine deposits
provide evidence of phases of enhanced humidity prior to the last glacial maximum and during the Holocene. In contrast, the
bedding attitudes of miliolites in SE Oman suggest that the Wahiba Sands were transported from south to north by a branch of the
SW Monsoon. The depositional ages of these dunes indicate a close connection between the winds and coeval fluctuations of the SW
Monsoon. The interdunal lakes and underlying dune sands reflect an active SW Monsoon during the Holocene. This is also
indicated by the aeolian and lacustrine records of the Thar desert in India, which likewise are controlled by the SW Monsoon. South
and west of the Oman Mountains is a broad alluvial fan (bajada) that is mostly inactive today. The oldest fluvial sediments are
undated but preliminary age estimates suggest that some correlate with more humid earlier interglacials. r 2002 Elsevier Science
Ltd. All rights reserved.
1. IntroductionFpresent climate
SE Arabia has an elevation that is mostly below 200 m
and incorporates the eastern part of the Rub al Khali
desert (Fig. 1). It is flanked by the Arabian Gulf to the
north, the Arabian Sea to the south and the Oman
Mountains and Gulf of Oman to the east. At present the
annual precipitation over the Oman Mountains reaches
over 200 mm locally (Fig. 2A). Most of SE Arabia now
has an annual rainfall that is below 50 mm, which, with
the exception of the Arabian Sea coast and eastern
Oman Mountains, generally occurs during the winter.
The vegetation that survives such conditions is described
in Ghazanfar and Fisher (1998).
*Corresponding author. 4 Morven Way, Ballater AB3 5SF, UK.
Fax: +44-0-13397-5507.
E-mail address: glennie [email protected] (K.W. Glennie).
Rainfall over Arabia today has two main sources:
(1) Atlantic late-winter depressions that track eastwards
over the Mediterranean Sea, southeast to the
Emirates and northern Oman Mountains (e.g.
National Atlas of the United Arab Emirates, 1993)
and then southwest across the Rub al Khali; and
(2) humid winds of the SW Monsoon that blow parallel
to Arabia’s SE coastline between about July and
September, a branch of which swings north to the
eastern Oman Mountains, occasionally leading to
torrential thunderstorms.
A similar pattern may have existed during interglacial
and interstadial periods. Despite occasional heavy rain,
most of the area remains hyper-arid today (Fisher and
Membery, 1998). Maximum summer temperatures exceed 501C over about half of the region (Fig. 2B).
0277-3791/02/$ - see front matter r 2002 Elsevier Science Ltd. All rights reserved.
PII: S 0 2 7 7 - 3 7 9 1 ( 0 1 ) 0 0 1 3 3 - 0
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
854
40˚
L
W
UM
US
Liwa
Wahibah
Uruq al Mutaridah
Umm as Samim
Mediterranean
Sea
Euphrates
Tigris
30˚
30˚
55˚
a
Ar
bi
a
200
n
Gu
lf
O
Gu
lf of
Om
an
m
an Mtn
s
10
Red
0
Sea
20˚
L
UM US
20
A
W
100
0
00
10
jaz
He
ir
As
Rub
li
l Kha
20˚
Arabian Sea
0
40˚
500 km
55˚
Drg. 120629
Fig. 1. Simplified relief map of Arabia and surroundings showing location of main areas of dune sand. Most of Arabia tilts gently to the ENE, away
from a highland range adjacent to the Red Sea. Eastern Arabia is flanked by the Tigris–Euphrates plain, the Arabian Gulf and, in the southeast, the
Oman Mountains. West of the Oman Mountains in the eastern Rub al Khali is a continental depression that contains the Uruq al Mutaridah (UM)
and the Umm as Samim (US), whose surface is only 59 m above sea level. Dune sands in yellow. L Liwa; W Wahiba Sands. Contours in metres.
The area is dominated by two wind systems (Fig. 3):
(1) The Shamal, which is mostly a winter wind that
blows down the Arabian Gulf towards the Emirates
and then turns clockwise across the Rub al Khali
where dune sands reach an elevation of some 1200 m
near the Yemen border (McClure, 1978) and,
(2) The SW Monsoon, a summer wind that blows
across the Arabian Sea from northeast Africa to
India, with a branch that veers due north across the
Wahiba Sands towards the Oman Mountains.
Evidence from deep-sea records suggest that in the
past, the two wind systems were largely controlled by
high-latitude glaciations (Kolla and Biscaye, 1977;
Sirocko et al., 1996). The Arabian Gulf exceeds a depth
of 50 fathoms (91 m) only in the Strait of Hormuz
(Kassler, 1973), therefore a drop in sea level of 120–
130 m (Shackleton, 1987) at the last glacial maximum
(LGM) implies that the Arabian Gulf was then dry.
Also, associated shifts in the location and strength of
those winds controlled the development of dunes of
differing orientation with time. As will be shown later,
the SW Monsoon was virtually ineffective over land
during much of the glacial cycle.
This contribution reviews the geomorphological
record of the SE Arabian desert and, based on this,
attempts to reconstruct the late Quaternary history of
the Shamal and SW Monsoon-related wind systems.
2. Quaternary geologyFregional perspective
The desert of SE Arabia has an extensive surface
cover of aeolian, fluvial and lacustrine sediments (Fig. 4)
that were deposited under different climatic and
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
855
Average Rain Fall mm
L
W
UM
US
00
1
Ar
Liwa
Wahibah
Uruq al Mutaridah
Umm as Samim
n
ia
ab
f
ul
G
100
10
0
10
L 50
dS
Re
50
0
20
0
US
M
W
ea
Rub
al K
hali
50
200
300
100
20
0
0
500 km
48
46
A
Maximum Temperature ˚C
L
W
UM
US
30˚
30˚
n
ia
ab
Ar
44
Liwa
Wahibah
Uruq al Mutaridah
Umm as Samim
f
ul
G
42
48
48
50
L
Re
US
dS
M
40
ea
20˚
Ru b
al K
40
46
W
20˚
hali
38
36
50
46
500 km
0
B
40˚
55˚
Drg. 121122
Fig. 2. Distribution of two factors that effect deserts. (A) Mean annual rainfall. Note that this is less than 50 mm over most of the Rub al Khali but
can exceed 200 mm in the Oman Mountains and 400 mm in the southern Hejaz Asir in Yemen. (B) Maximum Temperature, which exceeds 501C in
the SE Rub al Khali.
environmental regimes. Evidence of changes in relative
sea level is found where aeolian sandstones can be traced
below sea level along many parts of the Emirates coast,
.
offshore Muscat (Glennie and Gokdag,
1998) and along
the eastern margin of the Wahiba Sands. An extensive
deflation plain covers a large area of SW Oman.
Fig. 5 provides a generalized geomorphic map of the
region together with the locations of OSL-dated aeolian
sediments. Figs. 6A and B display the extent of
individual landforms in the Emirates and Oman. The
oldest Quaternary sediments in the region comprise
alluvial fans that spread away from the Oman Mountains. The size of the fans on the western side of the
mountains suggest that the region had a considerably
higher rainfall at some time in the past, and some of
their diagenetically altered components (barzamanite)
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
856
20˚
30˚
Sh
30˚
am
SW
M
on
so
on
al
n
NE
o
nso
Mo
0˚
0˚
SE
d
Tra
SE
de
s
es
0
30˚
Tr
a
1000 km
Semi Desert
30˚
Desert
20
Drg. 120140
Fig. 3. Present pattern of winds over Africa and Arabia and their seasonal reversals over east Central Africa and the Arabian Sea (NE and SW
Monsoons) relative to the Shamal of northern Arabia. Solid linesFnorthern hemisphere winter; dashed linesFsummer.
were possibly deposited during the late Pliocene to early
Pleistocene (Maizels, 1988). Pre-Holocene fluvial sequences are also exposed in Sabkha Matti in the NW
part of the area (Goodall, 1995). Fluvial channels are
still active intermittently, but erosion, partly by deflation, seems to be more dominant than accretion,
especially in upper-fan areas. At the distal extremities
of the fans, a little water and fine sediment is carried into
some former lacustrine areas such as the Umm as
Samim (Heathcote and King, 1998) and along the
Oman–Saudi–Emirates border SSW of Al Ain (Fig. 7A;
El-Sayed, 1999). Near the Arabian Sea coast, a former
lake, Sabkha Fuwat Ash Sham (Glennie et al., 1998) in
the Huqf fills a depression between eroded Precambrian
and Mesozoic strata. Similarly, Wadi Jurf, whose flow
of water is now mostly below the surface, has an
extensive salt crust, which makes it more a sabkha today
than a wadi (Glennie et al., 1998). As the term ‘sabkha’
implies, these former lakes (and rivers) are now the sites
of evaporite precipitation, thus indicating the effects of a
past change from a wetter to a more arid climate. Areas
of interdune sabkha such as the Uruq al Mutaridah
(Glennie, 1970) in Saudi Arabia have no inflow of
surface water, their salts being derived from ground
water. The salts of the Umm as Samim also seem to have
been derived mostly from the upward flow of artesian
water fed from the underlying Paleocene Umm er
Rhaduma aquifer rather than from the limited surface
supply (Heathcote and King, 1998).
The sedimentary sequences that immediately underlie
the ‘desert’ sediments in the region are not well studied.
Apart from the older alluvial-fan deposits, the Pliocene
may be represented only by a period of erosion (see, e.g.
Le Me! tour et al., 1995; Alsharhan and Nairn, 1997). The
exposed rocks include a transition from shallow-marine
carbonates to lacustrine deposits of Miocene age in
southern Oman (Jones and Racey, 1994), to the fluvial
deposits of the Baynunah Formation (Friend, 1999) and
the underlying aeolian sequences of the Shuweihat
Formation (Bristow, 1999) in the western Emirates.
In terms of aeolian processes, the Rub al Kali and the
Wahiba Sands provide a unique desert environment
influenced by two orthogonal wind systems that respond
to different climatic regimes. The winter Shamal winds
from NNW to SSE and the Summer monsoon winds
from SW to NE have shaped the aeolian sediments in
contrasting manners. In addition, aeolian accretion in
the Emirates has been supply limited on account of its
dependence on the changing water level in the Arabian
Gulf in response to glacially induced changes in global
sea level. Thus a comparative study of the timing of the
deposition of sediments in the region holds potential for
the reconstruction of the amplitude and direction of past
atmospheric circulation patterns in the region. These
can then be compared with the records from Arabian
Sea cores off the coast of Oman (e.g. Kolla and Biscaye,
1977) so as to understand the critical thresholds and
response times of sedimentary processes in this desert.
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
857
Hadhramaut
1000m
A
Deflation
Plain
Eo
Salahah
Arabian Sea
SSW
ce
ne
(S
ha
llo
w
Cr
Ba
se
in
eo
us
m
en
M
(la ioce
cu ne
st
rin
e
m
ar
et
ac
e)
(d
Mender
Lake
Dunes trend
WNW-ESE
Interdune water table
or defaltion plain
Fa
NNE
Dunes trend
SW-NE
Dunes trend
WNW-ESE
Wadis
A'
Extensive alluvial fan deposits from Oman Mountains underlie dune sands
rs
ee
t
Cover of linear dunes
tending WNW-ESE
pe
)
rm
ar
in
e
sh
el
ft
1000m
Oman
Mountains
)
e
llin
sta nt
Cry seme
Ba
B
ba
s in
Dunes overlying deflation
plain of shallow-marine
Early Miocene strata
Cambro
Pre-Cambrian
Huqf Group
Eocene
(Shallow
Marine)
Sabkha Matti
Miocene
&
older
Quarternary
gravel &
sand
Baynunah
Umm as Tawf
Samim Dawm
Miocene
(Shallow
Marine)
WNW
C
NNE
Ibra
Marbat
Arabian Sea
SSW
o
N.edge of Liwa
Gulf
of
Oman
Alluvial fan overlying
continental Mio-Pliocene
(e.g. Tawf Dawm)
WNW-ESE trending
dunes with fluvial and
lacustrine sediments
exposed in
interdune areas
Low Dunes
overlying fluvial &
aeolian Miocene strata
0
250
Batinah
Coast
Alluvium
B'
Narrow alluvial
fan overlain
by small dunes (5m)
ESE
Alluvial fan spreading away from the Oman Mountains
South central
Wahiba sands
Fahud
Old Wadi
gravel altered
to barzamanite
Eocene &
Cretaceous
exposed in
anticline
Ara
bia
n
Sea A'
C'
Modern dunes
overlie peneplaned
miliolite deposited
100 & 200ka BP
B' Gulf
Om of
an
al
Kh
al
i
C
Arabian
Sea
ab
B
Ar
A
ia
nS
ea
Ru
b
C'
Drg. 120633
0
Fig. 4. Schematic profiles of the surface sequences across SE Arabia: A–A from Salalah to Ras al Khaimah; B–B0 from Marbat to Sohar, on the
Batinah Coast; C–C0 from Sila, near Sabkhat Matti, to the southern Wahiba Sands. Apart from the mountainous areas of the south and the Oman
Mountains, the only pre-Miocene strata occur in the Fahud anticline. The centre of the area is below 100 m with gentle relief in the east (AA0 and
CC0 ) provided by the alluvial fans extending away from the Oman Mountains. Note that miliolite deposited between about 20 and 230 ka BP,
underlies the southern Wahiba Sands. Barzamanite, just west of the Wahiba Sands, comprises ophiolite-rich fluvial conglomerates in various stages
of alteration to dolomite (see also Fig. 6B).
3. Emirates
Fluvial and aeolian sediments extend over most of the
land surface of SE Arabia. The area west and south of
the Oman Mountains is covered with extensive alluvial
fans that spread away from the mountains, terminating
locally in the salt polygon-covered depression, the Umm
as Samim. West of the Saudi–Oman border, the distal
limits of the alluvial fans are overlain by dune sands of
the Rub al Khali, which extend northward across other
fans to the Emirates coast. There is a large stretch of the
Emirates between the alluvial fans west of the Oman
Mountains and the eastern side of Sabkhat Matti where
fluvial sediments of Quaternary age are unrecorded. The
bedding attitudes of those in Sabkhat Matti indicate
transport to the north and NE; suggesting that they
were derived from the mountains of western Saudi
Arabia and Yemen (see Goodall, 1995).
Large linear dunes possibly preserve their basic
outlines for tens of thousands of years (e.g. Lancaster,
1998, 1999) and, despite partial reworking by younger
winds that are not in equilibrium with them, can still be
used to deduce former wind directions. The dominant
sand-transporting wind in the Emirates is the northern
Shamal. Palaeowind data based on the axial orientation
of major linear dunes, supported by the bedding
attitudes of older, mostly undated, cemented dune sand
(Fig. 6A; Glennie, 1987, 1994), suggest that a WNW
(rather than NNW) component of the wind was
important during glaciations. With the global fall of
sea level associated with glaciations, quartz sands,
foraminifera and other carbonate shell material were
deflated from the newly exposed floor of the Arabian
Gulf and incorporated into dunes further south (e.g.
Kirkham, 1998; Glennie et al., 1999). Thus the Arabian
Gulf became a source of aeolian sediment and aeolian
transport from the north and NW. Conversely, the endglacial rise in sea level and consequent flooding of the
Gulf cut off that supply of sand to more southerly areas.
The wind did not cease, however. As a consequence,
858
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
Fig. 5. Outline geomorphic map of SE Arabia showing the distribution of major facies types. The locations of aeolian sediments that were dated
using IR fluorescence are numbered in order of increasing age of deposition (cf. Fig. 10, Table 1). At localities 3, 6, 9 and 13, the aeolian sands are
interbedded with fluvial gravels.
coastal dunes were deflated down to the level of the new
and higher water table formed in response to the high
interglacial sea level, thereby sourcing dunes further
down wind.
Fig. 7A indicates the general relief of the Emirates
and Fig. 7B gives the approximate depth of the presentday water table. During glacial periods of low sea level
and inferred aridity, the water table in inland areas
should have been well below the desert surface. At the
peak of interglacial higher sea level and inferred coeval
higher rainfall, the water table rose to the surface in
many interdune areas to create temporary lakes and
vegetated swamps, many of which have since converted
into inland sabkhas. Under the generally arid conditions
that have prevailed during the past 5000 years, the
deflated coastal flats acquired a crust of halite after
every high tide, and gypsum crystals have grown within
the sediment to create modern sabkhas. Because
foraminiferal tests are relatively weak, they become
pulverized during aeolian transport and the carbonate
content of dune sands is reduced to zero down wind
from the coast within about 80–100 km.
As part of the long-term movement of sand dunes,
some early interdune areas were first protected by a
dune cover and later exposed to deflation. The outcome
of such a history of differential burial and exposure, the
latter associated with a lower water table, is that small
mesas are exposed locally adjacent to active dunes.
Some mesas exhibit sequences of interbedded aeolian,
lacustrine and sabkha sediments.
4. Oman
The alluvial fans south and west of the Oman
Mountains form a major, gently sloping, slightly
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
55
AD
D
JD
RK
26
859
Straight of Hormuz
Abi Dhabi
Dubai
Jebel Dhanna
Ras al Khaimah
26
RK
Wind direction
deduced from bedding
Gulf
of
Oman
Oman
Arabian Gulf
D
AD
a
Meg
Linear
JD
as
Co
ah
tin
Ba ins
a
unt
Mo
Coastal
Sabkha
J.Hafit
Dunes
t
Outcrops of Baynunah
Fm.
Me
ga
li
D
nea eflat
e
rd
une d
s
Small
transverse
dunes
Small
Linear
Dunes
Sabkhat
Matti
Al
Barchanoid
Mega dunes
Liwa
lu
vi
al
Fa
ns
22
22
li
ha
0
A
Ru
100km
Di
56
Umm
as
Samim
U
Mu ruq a
tar
i da l
h
b
rn
ste
Ea
K
al
Deflation
Plain
55
Gulf of Oman
58
ss
e
Fa cted
n
Oman Mountains
Sur
uv
B
Fahud
ia
Out
ll
crop
s
M
Natih
A
WB
ath
a
High Wahiba
l
22
tter
ed
22
Fa
n
i
ad
W
Umm
as
Samim
Sca
B
An
da
m
Low
Wahiba
Ras Ruways
Deflation Plain
Sabkhas
Aeolian Sands
Alluvial Fans
Barzamanite
Pre-Quaternary
FA
Eastern
Rub al Khali
ai
n
tio
fla
Pl
M
as
ira
h
Baar
al
Hikman
n
Huqf
De
20
WJ
Arabian Sea
B
0
56
100km
58
B
FA
M
WJ
WA
RR
Barzamanite
Sabkha Fuwat Ash
Jebel Madar
20
Wadi Jurf
Wadi Andam
Ras Ruways
Wind direction
deduced from bedding
Drg. 121123
Fig. 6. Generalised geomorphic maps. (A) The Emirates and central Oman. Note that the Baynunah Formation comprises late Miocene fluvial
sediments. Arrows show palaeowind directions deduced from exposed bedding. (B) Southern Oman. Note that Wadi Andam extends over 200 km
from the mountains to reach the sea between the Huqf and Barr al Hikman. The SW Monsoon blows from south to north, deflating the Barr al
Hikman and building the high Wahiba dunes.
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
860
55˚
52˚
A
Oman
Arabian Gulf
Dubai
25
25˚
75
12
5
0
A
s
Arab
24
Al Ain
ins
rate
Emi
a
Mount
600
Abu Dhabi
24˚
Matti
United
75
Alluvial Fan
150
Sa b k h
ati
Liwa
Oman
B
Saudi Arabia
100 km
55˚
5
0
12
52˚
Drg. 121128
Relative Dune Height
B
NNE
SSW
Relative Dune Height (m)
5 to 20
Low dunes
30 to 50
Higher Dunes
110 to 150
Liwa
metres
metres
200
200
Coastal
Sabkha
100
100
Sea Level
Sea Level
A
VERTICAL EXAGGERATION ~ 600:1
Interdune
Sabkha
B
Fig. 7. (A) Relief map of the Emirates. Contours in metres. Simplified from United Arab Emirates University (1993). (B) Approximate surface
profile A–B along a 180 km NNE–SSW transect from the coastal sabkha SE of Abu Dhabi City to Shah among the giant barchanoid dunes of the
Liwa. These dunes are separated by kidney-shaped evaporite-encrusted interdune areas at about the level of the water table (dashed line) that involve
older dune sands. Dunes nearer the coast are underlain by miliolite (cemented carbonate-rich dune sands derived from the exposed floor of the
Arabian Gulf).
dissected plain (Fig. 6B). Most of the rainwater falls
over the central Oman Mountains, where it averages up
to 200 mm/year. Although in most years a few of the
major wadis briefly carry water over part of their course,
it is a relatively rare event for them to be filled with
water over their whole length. Just how long the alluvial
fans have been developing is not known, but two factors
attest to the considerable antiquity of at least some of it.
Firstly, differential erosion over parts of the fan area has
resulted in the exhumation of former river channels that
now form both straight and meandering ridges (Glennie,
1970, Figs. 19 and 20); presumably the finer and more
poorly cemented interfluvial sediments have been
deflated away. These ridges can occur up to 20 m or so
above the level of the present ‘active’ wadi floor. The
straighter ridges suggest an origin by flash floods in a
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
semi-arid environment, while the meandering ridges
imply at least a seasonal flow of water (Maizels, 1988).
Maizels and McBean (1990), using remote sensing
techniques, have identified a sequence of 14 partly
superimposed channels. The second factor indicating a
considerable age is that many of the deeper fluvial
channels of the area contain a variety of boulders
derived from the ophiolites of the Oman Mountains.
Many of these ferro-magnesian rocks have now been
partly to completely altered to dolomite, presumably in
a sub-surface diagenetic environment, making an
alteration suite named by Maizels (1988) as barzamanite
after the local village Barzaman. The areas rich in
barzamanite (Fig. 6B) show up clearly on Landsat
images as a light grey colour across which the black
(desert varnish) meandering ridges of exhumed channels
can be traced. Small outcrops of barzamanite (‘silicified
crust’ of Glennie et al., 1974) occur along the western
edge of the northern Oman Mountains.
The channels of the alluvial fan either drain into saltpolygon-covered depressions such as the Umm as
Samim, or are overlain by dune sands along the eastern
margin of the Rub al Khali or the western Wahiba
Sands. The channel of Wadi Andam reaches the Gulf of
Masirah between the southern Wahiba Sands and the
Huqf. Wadi Batha flows southeastward across the
northern end of the Wahiba Sands to reach the Arabian
Sea, with a sabkha-rich branch spreading south parallel
to the eastern edge of the Wahiba Sands. Southeast of
the salt dome Jebel Madar, the channel of Wadi
Mahram extends to the southeast beneath small dunes
of the Wahiba Sands. The presence of ophiolite pebbles
in interdune areas close to the Arabian Sea coast, both
north and south of Ras Ruways, indicates that active
wadis once extended that far from the Oman Mountains
before the current development of the Wahiba Sands as
a sand sea.
The Wahiba Sands are dominated by linear dunes
aligned approximately N–S, the largest of which, up to
100 m high, occur in the northern half of the area (see
e.g. Jones et al., 1988). The dunes were formed by a
branch of the SW Monsoon that blew from S to N
towards the Oman Mountains. The dune sands have up
to 30–45% carbonate grains, presumably derived mostly
from the adjacent exposed continental shelf. In the
south, the Wahiba Sands are underlain by cemented
carbonate dunes referred to as ‘miliolite’ after similar
sandstones in NW India (e.g. Pilgrim, 1908; Biswas,
1971; Patel and Bhatt, 1995). The bedding attitudes of
the miliolite indicate deposition by winds that, like
today’s SW Monsoon, blew essentially to the north or
NNW (Fig. 6B; Glennie, 1970, Fig. 86). Ophiolite grains
form only a small proportion of the dune sand (Allison,
1988) except in the NE corner of the Wahiba where their
presence is indicated by a darker colour seen on Landsat
imagery and aerial photographs. To the north of Wadi
861
Batha are some isolated masses of dune sand on the
same size scale (B60 m high) as the northern Wahiba
Sands (Fig. 8). It is thought that these isolated dunes
represent a former northern extension of the Wahiba
Sands that became isolated by the effects of post-glacial
to Holocene flooding of Wadi Batha on a scale that does
not occur today. Far to the west in Yemen, Le! zine et al.
(1998) describe a lacustrine development that they
consider to be coeval with the maximum activity of
the SW Monsoon from 7.8 to 7.2 ka BP. It is hoped that
the authors will soon be able to compare the depositional ages of the dune areas north and south of Wadi
Batha.
The Barr al Hikman at the southern end of the
Wahiba Sands (Fig. 6B) comprises relics of MioPliocene sediments of the upper Fars Group together
with a sabkha surface. As in the Emirates, it is suggested
that formerly this was the site of sand dunes being
transported to the north by winds of the SW Monsoon.
The supply of sands was cut off by a rise in post-glacial
sea level, deflation lowered the surface to the water
table, and the area converted to a sabkha in recent
millennia.
Deflation has been a major factor in controlling the
geomorphology of large areas of southwestern Oman.
Because the track of the Shamal curves around towards
the SW, much of the area SW of the Huqf is not the site
of major dunes transported from the north but of a
deflation plane (Figs. 5 and 6B). The NW landward edge
of the SW Monsoon blows in exactly the opposite
direction to that of the Shamal. The net result seems to
have been two periods of deflation inland from the
coast, with Lower Cenozoic rocks now forming the
surface of the deflation plain. The dune systems S and W
of the Umm as Samim have developed a rectilinear
pattern that is capped by many star dunes. Exhumation
of the meandering fluvial channels near Barzaman,
referred to above, was probably a result of very strong
deflationary conditions in an essentially sand-free
environment.
As discussed above, the broad stratigraphic relationships between different lithofacies has been established,
and these offer an excellent record of Quaternary
climatic change, with geomorphic processes being
controlled by contrasting wind regimes and sea-level
changes. However, the chronology and duration of the
depositional ages of the fluvial and aeolian facies, and
ensuing non-deposition or erosion, have yet to be
established.
5. ChronologyFpresent status
Most of the chronological studies of this area were
based initially on the use of radiocarbon dating of
carbonate-rich sediments with occasional dates on other
862
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
Fig. 8. Photogeological sketchmap of the northern end of the Wahiba Sands (Fig. 6B) and, north of Wadi Batha, of isolated megadunes of similar
size and orientation. The NNE–SSW trending dunes of the northern Wahiba seem to have been truncated by Wadi Batha, while the isolated dune
masses SE of Az Zahir are preserved in interfluvial areas or down-stream side of small hills. Outcrops shown in dark grey. Dune sands in a well at the
south end of the Hawiyah oasis are dated at 110 and 117 ka (OM 16A and B in Table 1 and locality 10 in Fig. 5), whereas at locality 3 near Al
Mintrib, aeolian sands interbedded with wadi gravels (OM 15B) have an age of only 10.374 ka (Juyal et al., 1998). This may indicate the time of
truncation of the Wahiba dunes during high rainfall at about the onset of the Holocene. N–S trending metre-high linear dunes cover much of the area
immediately north of Wadi Batha.
organic remains. More recently the use of Luminescence
dating (both infrared stimulated luminescence (IRSL)
and green light stimulated luminescence) and highprecision thermal ionization mass spectrometric data on
U-Th series disequilibrium, has proved invaluable.
Radiocarbon dating of ground waters of 6–30 ka has
also been cited (Macumber et al., 1998) but, because of a
current preoccupation with the depositional ages of
dune sand, a discussion of these is beyond the scope of
this review.
Over one hundred radiometric ages have been
compiled from the published literature. McClure
(1976, 1984) gave radiocarbon dates on shells from
interdune lacustrine environments within the Rub al
Khali, The ages ranged from 6 to >37 ka. Radiocarbon
ages on other materials ranged from about 17.5–32 ka.
McClure, and more recently Sanlaville (1992a, b), used
additional radiocarbon dates on shells, marl, travertine
sinter crust and wood to infer two humid periods dated
to 30–20 and 9–6 ka BP. Despite the possibilities of
contamination, the overall similarity of dates led
Sanlaville to conclude that the inferred chronology of
the humid phases was reasonable. Wood and Imes
(1995) reported radiocarbon ages on paleocapillary
carbonate deposits ranging from 12.2 to 42.9 ka BP
with a peak at 25–35 ka confirming the initial conclusions of McClure (1976) and Sanlaville (1992a, b) of a
humid phase preceding the last glacial epoch. Based on
hydrological reasoning, Wood and Imes further inferred
that the annual rainfall in the Liwa region at B28 ka
must have been B200 mm compared to 50 mm or less at
present.
Sanlaville (1992a, b) published 14C dates on samples
from boreholes in the coastal plain of Sharjah, which
show that alluvial sands and gravels older than 42 ka are
overlain by dune sands with a 34 ka age. These are
separated by undated sands and silts and overlain by
dune sand with ages of approximately 22 and 19 ka, over
which marine deposits of the flooding Arabian Gulf
were deposited about 6.5 ka BP. Younger undated sand
dunes cap the sequence. Although no details are
available on the exact material dated, the results do
bear testimony to a long record of changing sedimentary
regimes.
Gardner (1988) obtained 14C ages of 60807800 and
7980790 ka BP from mollusc and gastropod shells
collected from near-coastal interdune and ‘mesa’ localities of the eastern Wahiba Sands north of Ras Ruways
(Fig. 6B). Gardner also provided radiocarbon dates for
mollusc shells from a 2 m ‘raised beach’ at 32707600 yr
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
6
Probability
4
2
0
0
10000
20000
30000
40000
Age (a)
Fig. 9. Probability plot of radiocarbon ages from Arabia constructed
using the method described by Venkatesan and Ramesh (1993). The
raw data are derived from McClure (1976, 1984), Gardner (1988),
Sanlaville (1992a, b), and Wood and Imes (1995). Note the clustering
of ages at B7 and 26 ka.
BP. Based on geological reasoning, and in the absence of
any evidence of neo-tectonics, these ages should have
been closer to 6 ka when sea level was slightly higher
than at present. This suggests that the radiocarbon ages
in these cases have been altered diagenetically. Methodologically, the radiocarbon ages on the shells are
suspect (Head, 1999); this is borne out by the fact that
ages of two molluscs from the oldest ‘raised beach’,
collected 13 m above present sea level, were 21 280728
and 31 1107530 ka BP. According to Shackleton’s
(1987) delta18O sea-level curve, sea level at 21 and 31 ka
was over 100 m lower than the present level, and such
ages on a +13 m raised beach therefore appear
geologically inconsistent. Thus, although 14C dates
may give valuable relative ages for events, they cannot
be trusted as stand-alone calendar ages of events in view
of possible diagenetic changes and contamination of the
samples, particularly in environments with a rich
productivity of carbonate shells and extreme climatic
conditions. Fig. 9 is a probability plot of radiocarbon
ages from all the sources, using the method of
Venkatesan and Ramesh (1993). Note that the clustering
of ages at 7 and 26 ka broadly correspond with those
discussed above.
Using isotopic and radiometric dating based on U–
Th, 87Sr/86Sr and 14C on palaeodune sediments of the
western Emirates, Hadley et al. (1998) found that an
older sequence (Ghayathi Formation) was deposited
before 160 ka, whereas cementation of the overlying
interdune sandstone (Aradah Formation) occurred
between about 12 and 70 ka BP.
The development of luminescence dating (Singhvi
et al., 1982; Wintle, 1993) offered a good possibility of
providing ages to the depositional events of siliciclastic
sediments. Goodall (1995) reported OSL/TL ages of
5.970.5 and B208 ka on aeolian sands, and 4072.7
863
and 147712 ka on fluvial sands in Sabkhat Matti
(Fig. 5), and Pugh (1997) reported OSL ages of 45 and
164 ka for dune sands from the Liwa (see Table 1). Juyal
et al. (1998) presented a series of ages on different
sediment types from the Emirates and Oman to provide
a first-order event stratigraphy in the region.
More recently, Burns et al. (1998) provided highresolution U–Th ages on cave speleothems from the
Hoti caves in Oman, which indicated a more humid
phase from 9.6 to 6.2 ka and around 125 ka, and a
transition from wet to dry conditions that occurred at
117 and 6.2 ka. It was suggested that these humid
episodes were linked closely to the glacial boundary
conditions. Burns and his co-workers (Weyhenmeyer
et al., 2000) also show that the ground temperature in
northern Oman during the late Pleistocene (15–24 ka
BP) was some 6.51 lower than that of today.
In the following, all the chronological work is
synthesized to provide a first-order event stratigraphy,
and is then compared with the record of glaciations. It
must be emphasized that the data on chronology is still
very limited, so caution must prevail on any overuse of
the interpretations attempted here.
6. Discussion
The distribution of the main Present and earlier
Quaternary depositional environments of SE Arabia has
been illustrated in various ways in Figs. 1–8, and the
clustering of published 14C ages has been displayed in
Fig. 9. Finally the timing and duration of the inferred
environments are compared with the glacial and marine
record of climatic change.
In view of the difficulties in accepting the accuracy of
radiocarbon ages per se, the discussion below is based
largely on IRSL, OSL and TIMS U-Th ages, and the
radiocarbon ages are used as supporting evidence. The
inferences on the depositional environmental/climatic
correlations and their timing are based on limited
available dates and therefore should be treated with
due caution. In view of the evidence of a direct control
of sea level on the sedimentary processes, a correlation
with the marine oxygen istopic curve is made to support
some of the inferred periods of aridity and humidity.
Fig. 10 shows a summary of the separate influence of the
Shamal and SW Monsoon on events in the Emirates and
Oman (see also Table 1). The overall chronology
indicates that the record of events exposed on the
surface spans a long time, suggesting rather low net
accumulation rates, and that the wind acted as an agent
of both accretion and erosion. The ages reflect a long
record of climatic change with a close correlation with
the wind systems, which in turn were linked to the global
climatic cycles.
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
864
Table 1
Tabulation of sediment type, inferred climate and wind direction during deposition, and luminescence age of mostly aeolian sands from the Emirates
and Omana
Locality
On Fig. 5
Sample
Description
Inferred climate
Wind type (direction from)
Age in ka
The Emirates and Oman-influence of the Shamal (note: licalities
Dunes greater Liwa area
1
OM4A
Sub-sabkha lacustrine
4
AD5
Sub-sabkha dune sand
5
AD9
Aeolian in Liwa
6
AD11
Intrafluvial aeolian
7
AD4
Interdune mesa
8
AD3A
Aeolian
8
F
Interdune swamp
8
AD3B
Aeolian
9
OM2
Intrafluvial aeolian
12
AD7
Exhumed aeolian
13
OM5A
Intrafluvial aeolian
1,9 and 13 are in Oman)
Hyper-arid
NNW
Humid/arid
?
Hyper-arid
NNW
Hyper-arid
NNW
Humid/dry/humid
?
Hyper-arid
NNW
Hyper-arid
NNW
Humid
?
Hyper-arid
NNW
Arid
?
Humid/dry/humid
?
Humid/dry/humid
?
Shamal
Stadial?
Holocene o6
6.070.6
1272
1573
3175
4074.5
64723
Undated
99714
104738
141788
354757
The EmiratesFThe Liwa Area (Pugh, 1997, OSL dates)
Aeolianite
Aeolianite
Aeolianite
Aeolianite
Aeolianite
Aeolianite
Aeolianite
Hyper-arid
Hyper-arid
Hyper-arid
Hyper-arid
Hyper-arid?
Hyper-arid
Hyper-arid
NNW
NNW
NNW
NNW
NNW
NNW
NNW
Shamal
Shamal
Shamal
Shamal
Shamal
Shamal
Shamal
45
51
54
60
113
134
164
The EmiratesFSabkha Matti Area (Goodall, 1995, OSL dates)
Aeolian
Fluvial
Fluvial
Aeoliian beneath duricrust
Hyper-arid
Humid
Humid
Hyper-arid
N
?
?
N
Shamal
Interstadial?
Interstadial?
Shamal
5.970.5
4072.7
147712
208721
OmanFinfluence of SW Monsoon
2
OM12A
‘oasis’
2
OM13A1
Aeolian
2
OM13B1
Aeolianite (miliolite)
2
OM13B2
Aeolianite (miliolite)
3
OM15B
Interfluvial aeolian
10
OM16A
Aeolian
10
OM16B
Aeolian
11
OM8A
Aeolianite (miliolite
11
OM8B
Soil horizon
11
OM 8D
Aeolianite (miliolite)
Humid
Hyper-arid?
Hyper-arid
Hyper-arid
Humid/dry/humid
Hyper-arid
Hyper-arid
Hyper-arid
Humid
Hyper-arid
?
SW
S
S
?
S
S
S
?
S
Holocene
Monsoon
LGM
LGM
Early Holocene
SW Monsoon
SW Monsoon
SW Monsoon
8.671.0
10.374
1873
2373
1071
110711
117712
112712
Undated
229719
Shamal
Mid Holocene
Shamal
Shamal
Shamal
Shamal
Shamal
SW Monsoon
a
All ages are plotted in Fig. 10. Sample localities, except those of Goodall from Sabkha Matti and Pugh from the Liwa, are shown in Fig. 5. The
AD and OM sample numbers are those quoted in Juyal et al. (1998).
In the Emirates, alignments of the long axes of the
dune systems and paleowind directions deduced from
bedding attitudes of the miliolite outcrops permit the
wind directions to be deduced and provide useful
evidence on the timing of relative changes in the
strength of the Shamal in the past. The geological
record suggests that during glacial maxima, the wind
crossed the southern Gulf from the WNW rather than
the present NNW or N. This implies that during
glaciations, the high-pressure trade-wind ‘wheel-around’
over Arabia was squeezed southward towards the
Equator, effectively keeping the weaker SW Monsoon
system away from the Arabian coast. Termination of the
northern hemisphere high-latitude glaciations both
weakened the global wind systems and allowed them
to migrate polewards (Fig. 11). This permitting the SW
Monsoon to be effective not only along the coast of SE
Arabia but, as can be seen from Landsat imagary, to
extend its influence to the SE margin of the Rub al
Khali, up to 400 km inland. Fluvial sands are dated at 40
and 147 ka and wind-blown sedimentary layers in
otherwise fluvial sequences are dated to 354 and
104 ka, while periods of Shamal-related enhanced dune
building activity occurred around 160–130, 110, 60–50
and 15–12 ka. These events appear to correlate with the
periods of glacial maximum and to transitions to a more
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
APPROX. SEA LEVEL (m)
AGE
(Ka)
0
-50
-100
AGE
(Ka)
-125
SHAMAL
0
G & OM 4 6
AD 5 12
AD 9 15
MONSOON
0
1
8
10
18
23
OM 12A
OM 13A1,15B
OM 13B1
OM 13B2
AD 11 31
GF & AD 4 40
P 45
50
P P 51
54
P
AD 3A 60
64
50
AD 3B 99 100
OM 2 104
P 113
OM 16A
OM 8A
OM 16B
2
P 134
AD 7 141
GF 147
150
100
110
112
117
150
P 164
200
G 208
229 OM 8D
250
Ka BP
I N T E R G L A C I A L S
3
Ka BP
300
G L A C I AT I O N S
250
200
300
4
350
OM 5 354
350
400
400
5
450
450
500
500
Fig. 10. Approximate sea-level curves of the past 500 ka (modified
from Boulton, 1993), with the OSL ages of aeolian sands alongside.
AD samples from Abu Dhabi and OM samples from Oman published
in Juyal et al. (1998); localities given in Fig. 5 (see also Table 1). P
samples from Pugh (1997) and G samples from Goodall (1995). Note
that GF denotes Goodall samples of fluvial origin. In principle, the
lowest sea levels are thought to coincide with maximum high-latitude
glaciations (increasing age from 1 to 5) and the strongest desert winds,
whereas the interglacials record warmer and wetter conditions with a
weaker Shamal but a SW Monsoon that is active along the SE coast of
Arabia.
humid period, which not only dictated the winds but
also provided the sediment supply. The apparent
absence of dune deposition around the LGM (24–
18 ka) may be an artefact of incomplete sampling
together with preferred deflation and transport at the
studied sites.
Aeolian activity in Oman appears to be linked more
to transitional periods with enhancing activity of the SW
monsoon. The principal dune-building episodes are seen
865
at 220, 110 and 23–10 ka, which is similar to those seen
in the Thar desert (Singhvi and Kar, this volume).
First in a sequence stratigraphic overview of the
Sahara Desert, and then as a series of hypotheses,
Kocurek (1998, 1999) pointed out that the preservation
of aeolian sediment depends on accommodation space,
coupled with control on the level of the water table,
which was low during glacial aridity and lower sea level,
and high during interglacial humidity and high sea level.
During glacial periods, aeolian sediments were derived
by deflation of up-wind unconsolidated alluvial and
lacustrine sequences deposited during earlier interglacial
periods of higher rainfall and fluvial activity. Indeed,
during glacial maxima, the Arabian Gulf was dry, and
the united Tigris–Euphrates River reached the sea only
south of the Strait of Hormuz (Sarnthein, 1972; Glennie,
1994, 1998; Lambeck, 1998; Teller et al., 2000). At that
time, dune sands migrated across the southern Arabian
Gulf to the Emirates and beyond to the Rub al Khali.
As sea level fell, carbonate grains, deposited in the
shallow marine waters of an earlier interglacial Gulf,
were deflated and transported across the present
Emirates coast line. During glacial periods of strong
wind activity, the Shamal should have continued to
build sand dunes with supply being the limiting factor.
Flooding of the Gulf during a succeeding interglacial
period terminated the supply of sand from the north and
northwest. As the wind persisted, the sand dunes at the
new coast were deflated down to the prevailing water
table, thereby becoming the site of sabkhas (Evans et al.,
1964, 1969). Sands derived by this deflation were
transported to form new dunes or modify older ones
at the prevailing wind strengths and directions. This
implies that in the Emirates, major aeolian bounding
surfaces should have formed during humid interglacial
periods as older dune accumulations were cannibalized
or partly stabilised, only to have their surfaces
reactivated by the strong dry winds of the succeeding
glacial period. The deflated surfaces of older, relatively
small, linear dunes are exposed in the central Wahiba
Sands (Fig. 75 in Glennie, 1970). As these are still
undated, one can only speculate on the relative times of
their deposition and subsequent deflation.
The above implies that accumulations on currently
stable continental margins, such as the Wahiba area of
Oman and also in the Emirates, have a low preservation
potential, and that periods of erosion or non-deposition
are likely to be of longer duration than those of
deposition. This is borne out from samples at locality
OM8 (Juyal et al., 1998; locality 11 on Fig. 5) where
within a vertical section of some 20 m there are a
minimum of eight aeolian sequences each separated by
sub-horizontal bounding planes and the relic of a soil
horizon. The dated time span between the two extreme
samples at this locality is almost 120 ka (i.e. a full
glacial–interglacial cycle).
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
866
50°
80°
ha a
l
a
30°
30°
Shamal2
0Ka
Ka
-14
0
n
oo
ns
Ka
o
M
20
.
n
o
SW
so
on
M
.
SW
0
1000 km
50°
Desert
20Ka
Desert
0-14ka
80°
Wind Direction
0-14Ka
20Ka
Fig. 11. The different trends and locations of the Shamal and SW Monsoon at 20 ka BP and from 0–14 ka BP, together with the apparently different
distribution of active dune sands in the eastern Sahara (based partly on Sarnthein, 1978).
In Oman at locality 10 (sample OM16a,b) two aeolian
sand samples 50 cm apart at the bottom of a well in the
Hawiyah oasis (northern end of the Wahiba Sands;
Fig. 8) and overlying a fluvial conglomerate were
luminescence dated to 112 and 117 ka. The northern
end of the Wahiba Sands were apparently truncated by
the fluvial action of Wadi Batha. At locality 3 to the
northwest fine aeolian sands (OM 15B) interbedded with
fluvial gravels close to the edge of the wadi at Al Mintrib
have an age of 10 ka. The gravels would represent fluvial
activity during the Climatic Optimum following the last
glaciation. Evidence of the climatic contrast between
glacial and interglacial times is seen much farther south
at OM 13 (‘Oasis’ locality 2 on Fig. 5). There miliolite
(dated to 23 and 18 kaFLGM and already cemented
into a hard rock) has been exposed long enough to form
a series of almost N–S (10–1901) yardangs up to 1 m
high and is overlain by friable dune sand (dated to
10 ka) which grades up into a mesa comprising an
interdune lacustrine sequence of interglacial age the top
of which is dated to 8 ka. The mesa is in danger of being
enveloped from the south by sands of a mobile
transverse dune.
In the Emirates at locality 8 on Fig. 5 (samples AD3A
3B) two aeolian sequences dated at 64 and 99 ka are
separated by a metre of swamp-like interdune sediments.
The humidity in this case presumably coincided with an
interstadial possibly around 80 ka.
Anderson and Prell (1992, 1993) show that in the
Arabian Sea, glacial–interglacial cyclicity is more clearly
expressed by the greater abundance of foraminifera
found in cores taken close to the coast of Arabia than
over the Owen Ridge some 400 km to the SE. It was
shown that the strongest monsoon winds, as inferred
from upwellings, occurred during interglacials. Sirocko
et al. (1996) indicate that during glacial times, much of
the dust deposited over the Arabian Sea was derived
from the Arabian Gulf and northern India, implying
that the Shamal (and NE Monsoon) extended southward beyond the land limit of Arabia, at about
rightangles to the axis of the SW Monsoon. They also
show that the SW Monsoon was re-established in three
stages beginning around 14.3 ka and ending at 11.5 ka
BP as the last northern hemisphere glaciation declined.
Although active during different seasons, intensification of the SW Monsoon probably coincided with a
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
weakening of the sub-tropical anticyclone over Arabia,
and a retraction northward of the Shamal. The
combined observations of Anderson and Prell (1992,
1993), Sirocko (1994) and Sirocko et al. (1996) indicate
that the SW Monsoon was more active close to the
Arabian coast than over the Owen Ridge, and also
during interglacial rather than glacial times, times that
fit well with dune activity in the Thar Desert of India
(Fig. 11; Singhvi and Kar, 1992). As shown by Sarnthein
(1978), in the general area of modern deserts, there has
formerly been some considerable glacially induced
latitudinal shifts of dune-forming winds and associated
aridity or humidity (Fig. 11; see also Petit-Maire, 1994;
Yan and Petit-Maire, 1994). A similar shift in the respective areas of activity of the Shamal and SW Monsoon
affected the timing of dune activity over SE Arabia and
over the Thar Desert in India (Figs. 11 and 12).
867
7. Conclusions
During the past 350 ka or more, the orientation of
the long axes of major systems of linear dunes in
southeast Arabia were controlled mostly by the
effects of northern high-latitude glaciations, whereas
the interglacial periods were times of higher rainfall
and fluvial activity. Glacial activity coincided with a
dry Arabian Gulf whose former marine sediments
were deflated and transported southward by the strong
Shamal (northern) wind. Collapse of especially the
northern high-latitude glaciations caused the Shamal
wind system to weaken and retract its influence northward; this caused a shift in wind direction in the
Emirates, and permitted the SW Monsoon to take
a more northerly route close to the Arabian coast
and over the Wahiba area of Oman during late glacial
Fig. 12. Sketch map indicating the shift in location and size of the African, Arabian and Indian deserts between the last Pleistocene glaciation and
now, based largely on the distribution of former and present dune sands and their axial orientations (modified from Sarnthein, 1978). There was a
shift in wind pattern and probable areas of mobile dune sand between glacial and interglacial periods.
868
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
times, and even over the adjacent land during the later
Holocene.
Acknowledgements
PD Oman and Abu Dhabi Onshore Oil Operating Co.
are thanked for logistical support during collection of
the OM and AD samples referred to in Table 1. Fig. 10
was drafted by Barry Fulton, University of Aberdeen,
and the remainder by Jackie Morrison, Shell UK Ltd.,
Aberdeen.
References
Allison, R.J., 1988. Sediment types and sources in the Wahiba Sands.
In: Dutton, R.W. (Ed.), The Scientific Results of the Royal
Geographical Society’s Oman Wahiba Project 1985–1987. Journal
of Oman Studies Special Report No. 3, pp. 161–168.
Alsharhan, A.S., Nairn, A.E.M., 1997. Sedimentary Basins and
Petroleum Geology of the Middle East. Elsevier, The Netherlands,
942pp.
Anderson, D.M., Prell, W.L., 1992. The structure of the southwest
monsoon winds over the Arabian Sea during the Late Quaternary:
observations, simulations and marine geologic evidence. Journal of
Geophysical Research 97 (C10), 15481–15487.
Anderson, Prell, 1993. A 300 kyr record of upwelling off Oman during
the Late Quaternary: evidence of the Asian Southwest Monsoon.
Paleoceanography 8(2), 193–208.
Biswas, S.K., 1971. The miliolite rocks of Kutch and Kathiawar
(western India). Sedimentary Geology 5, 147–164.
Boulton, G.S., 1993. Ice ages and climate. In: Duff, P.McL.D. (Ed.),
Holmes’ Principles of Physical Geology, 4th Edition. Chapman &
Hall, London, pp. 439–469.
Bristow, C.S., 1999. Aeolian and sabkha sediments in the Miocene
Shuwaihat Formation, Emirate of AbuDhabi, United Arab
Emirates. In: Whybrow, P.J., Hill, A. (Eds.), Fossil Vertebrates
of Arabia. Yale University Press, NewHaven, USA, pp. 50–60.
Burns, S.J., Matter, A., Frank, N., Mangani, A., 1998. Speleothem
based paleoclimatic record from Northern Oman. Geology 26 (6),
499–502.
El-Sayed, M.I., 1999. Sedimentological characteristics and morphology of the aeolian sand dunes in the eastern part of the UAE,
a case study from Ar’ Rub al Khali. Sedimentary Geology 124,
219–238.
Evans, G., Kendall, C.G.St.C., Skipwith, P., 1964. Origin of the
coastal flats, the sabkha, of the Trucial Coast, Persian Gulf. Nature
202, 759–761.
Evans, G., Schmidt, V., Bush, P., Nelson, H., 1969. Stratigraphy and
geological history of the Sabkha, Abu Dhabi, Persian Gulf.
Sedimentology 12, 145–159.
Fisher, M., Membery, D.A., 1998. Climate. In: Ghazanfar, S.A.,
Fisher, M. (Eds.), Vegetation of the Arabian Peninsula. Kluwer
Academic Publications, Dordrecht, pp. 5–38.
Friend, P.F., 1999. Rivers of the Lower Baynunah Formation, Emirate
of Abu Dhabi, United Arab Emirates. In: Whybrow, P.J., Hill, A.
(Eds.), Fossil Vertebrates of Arabia. Yale University Press,
NewHaven, USA, pp. 38–49.
Ghazanfar, S.A., Fisher, M. (Eds.), 1998. Vegetation of the Arabian
Peninsula. Kluwer Academic Publications, 362pp.
Gardner, R.A.M., 1988. Aeolianites and marine deposits of the
Wahiba Sands: character and palaeoenvironments. Journal of
Oman Studies Special Report No. 3, pp. 75–94.
Glennie, K.W., 1970. Desert Sedimentary Environments. Elsevier,
Amsterdam, 222pp.
Glennie, K.W., 1987. Desert sedimentary environments, present and
pastFa summary. Sedimentary Geology 50, 135–165.
Glennie, K.W., 1994. Quaternary dunes of SE Arabia and Permian
(Rotliegend) dunes of NW Europe: some comparisons. Zentralblatt
fur
. Geologie und Pal.aontologie Teil 1, 1199–1215.
Glennie, K.W., 1998. The desert of SE Arabia: a product of climatic
change. In: Alsharhan, A.S., Glennie, K.W., Whittle, G.L.,
Kendall, C.G.St.C. (Eds.), Quaternary Deserts and Climatic
Change. Balkema, Rotterdam, pp. 279–291.
.
Glennie, K.W., Gokdag,
H., 1998. Cemented Quaternary dune sands,
Ras Al Hamara housing area, Muscat, Sultanate of Oman. In:
Alsharhan, A.S., Glennie, K.W, Whittle, G.L., Kendall, C.G.St.C.
(Eds.), Quaternary Deserts and Climatic Change. Balkema,
Rotterdam, pp. 109–116.
Glennie, K.W., Boeuf, M.G.A., Hughes Clarke, M.W., Moody-Stuart,
M., Pilaar, W.F.H., Reinhardt, B.M., 1974. Geology of the Oman
Mountains. Verhandelingen van het Koninklijk Nederlands
geologisch mijnbouwkundig Genootschap, 423pp.
Glennie, K.W., Al-Belushi, J., Al-Maskery, S., 1998. The inland
sabkhas of the Huqf, Oman: a product of past extremes of
humidity and aridity. In: Alsharhan, A.S., Glennie, K.W., Whittle,
G.L., Kendall, C.G.St.C. (Eds.), Quaternary Deserts and Climatic
Change. Balkema, Rotterdam, pp. 279–291.
Glennie, K.W., Lancaster, N., Singhvi, A.K., Teller, J.T., 1999.
Responses of dune systems to climatic and sea level changes:
United Arab Emirates. Poster, XV INQUA Congress, 3–11 August
1999, Durban South Africa: The Environmental Background to
Hominid Evolution in Africa.
Goodall, T.M., 1995. The geology and geomorphology of the Sabkhat
Matti region (United Arab Emirates): a modern analogue for
ancient desert sediments from north-west Europe. Unpublished
Ph.D. Thesis, University of Aberdeen, 433pp.
Hadley, D.G., Brouwers, E.M., Brown, T.M., 1998. Quaternary
Paleodunes, Arabian Gulf coast, Abu Dhabi Emirate: age and
paleoenvironmental evolution. In: Alsharhan, A.S., Glennie, K.W.,
Whittle, G.L., Kendall, C.G.St.C. (Eds.), Quaternary Deserts and
Climatic Change. Balkema, Rotterdam, pp. 327–337.
Head, M.J., 1999. Radiocarbon dating of arid zone deposits. In:
Singhvi, A.K., Derbyshire, E. (Eds.), Paleoenvironmental Reconstruction in Arid Lands. Oxford & IBH Publishing Co., New Delhi,
pp. 293–326.
Heathcote, J.A., King, S., 1998. Umm as Samim, Oman: a sabkha with
evidence for climatic change. In: Alsharhan, A.S., Glennie, K.W.,
Whittle, G.L., Kendall, C.G.St.C. (Eds.), Quaternary Deserts and
Climatic Change. Balkema, Rotterdam, pp. 141–153.
Jones, R.W., Racey, A., 1994. Cenozoic stratigraphy of the Arabian
Peninsula and Gulf. In: Simmons, M.D. (Ed.), Micropaleontology
and Hydrocarbon Exploration in the Middle East. Chapman &
Hall, London, pp. 273–303.
Jones, D.C.K., Cooke, R.U., Warren, A., 1988. A Terraine classification of the Wahiba Sands of Oman. In: Dutton, R.W. (Ed.), The
Scientific Results of the Royal Geographical Society’s Oman
Wahiba Project 1985–1987. Journal of Oman studies Special
Report No. 3, pp. 19–32.
Juyal, N., Glennie, K.W., Singhvi, A.K., 1998. Chronology and
paleoenvironmental significance of Quaternary desert sediments in
SE Arabia. In: Alsharhan, A.S., Glennie, K.W., Whittle, G.L.,
Kendall, C.G.St.C. (Eds.), Quaternary Deserts and Climatic
Change. Balkema, Rotterdam, pp. 315–325.
Kassler, P., 1973. The structure and evolution of the Persian Gulf.
In: Purser, B.H. (Ed.), The Persian Gulf. Springer, Berlin,
pp. 11–32.
K.W. Glennie, A.K. Singhvi / Quaternary Science Reviews 21 (2002) 853–869
Kirkham, A., 1998. Pleistocene carbonate seif dunes and their role in
the development of complex past and present coastlines of the
UAE. GeoArabia 3, 19–32.
Kocurek, G., 1998. Aeolian system response to external forcing
factorsFa sequence stratigraphic view of the Saharan region. In:
Alsharhan, A.S., Glennie, K.W., Whittle, G.L., Kendall, C.G.St.C.
(Eds.), Quaternary Deserts and Climatic Change. Balkema,
Rotterdam, pp. 327–337.
Kocurek, G., 1999. The aeolian rock record (yes, Virginia, it exists, but
it really is rather a special one). In: Goudie, A.S., Livingstone, I.,
Stokes, S. (Eds.), Aeolian Environments, Sediments and Landforms. Wiley, New York, pp. 239–259.
Kolla, V., Biscaye, P.E., 1977. Distribution and origin of quartz in the
sediment of Indian Ocean origin. Journal of Sedimentary Petrology
47, 642–649.
Lambeck, K., 1998. Shoreline reconstructions for the Persian Gulf
since the last glacial maximum. Earth and Planetary Science Letters
142, 43–57.
Lancaster, N., 1998. Dune morphology, chronology and Quaternary
climatic change. In: Alsharhan, A.S., Glennie, K.W., Whittle, G.L.,
Kendall, C.G.St.C. (Eds.), Quaternary Deserts and Climatic
Change. Balkema, Rotterdam, pp. 339–349.
Lancaster, N., 1999. Geomorphology of desert Sand Seas. In: Goudie,
A.S., Livingstone, I., Stokes, S. (Eds.), Aeolian Environments,
Sediments and Landforms. Wiley, New York, pp. 49–69.
Le M!etour, J., Michel, J.C., B!echennec, F., Platel, J.P., Roger, J. 1995.
Geology and mineral wealth of the Sultanate of Oman . Bureau de
Recherches Geologiques et Minieres, Paris, France. 271pp.
L!ezine, A.M., Saliege, J.-F., Robert, C., Wertz, F., Inizan, M.-L.,
1998. Holocene lakes from Ramat as-Sab’atayan (Yemen) illustrate
the impact of monsoon activity in Southern Arabia. Quaternary
Research 50, 290–299.
Macumber, P.G., Al Abri, R., Al Akhzami, S., 1998. Hydrochemical
facies in the ground water of central and southern Oman. In:
Alsharhan, A.S., Glennie, K.W., Whittle, G.L., Kendall, C.G.St.C.
(Eds.), Quaternary Deserts and Climatic Change. Balkema,
Rotterdam, pp. 511–520.
Maizels, J., 1988. Palaeochannels: Plio-Pleistocene raised channel
systems of the western Sharqiyah. In: Dutton, R.W. (Ed.), The
Scientific Results of the Royal Geographical Society’s Oman
Wahiba Project 1985–1987. Journal of Oman studies Special
Report No. 3, pp. 95–112.
Maizels, J., McBean, C., 1990. Cenozoic alluvial fan system of interior
Oman: palaeoenvironmental reconstruction based on discrimination of palaeochannels using remotely sensed data. In: Robertson,
A.H.F., Searle, M.P., Ries, A.C. (Eds.), The Geology and
Tectonics of the Oman Region. Geological Society Special
Publication No. 40, pp. 565–582.
McClure, H.A., 1976. Radiocarbon dating of Late Quaternary lakes in
the Arabian Desert. Nature 263, 755–756.
. J.G.
McClure, H.A., 1978. Ar Rub’ Al Khali. In: Al-Sayari, S.S., Zotl,
(Eds.), Quaternary Period in Saudi Arabia. Springer, Wien, pp.
252–263.
McClure, H.A., 1984. Late Quaternary palaeoenvironments of the
Rub’ al Khali. Unpublished Ph.D. Thesis, University of London,
245pp.
Patel, M.P., Bhatt, N., 1995. Evidence of Palaeoclimatic fluctuations in
miliolite rocks of Saurashtra, western India. Journal of the
Geological Society of India 45, 191–200.
869
Petit-Maire, N., 1994. Natural variability of the Asian, Indian and
African monsoons over the last 130 ka. In: Desbois M., De! salmand, F. (Eds.), Global Precipitation and Climatic Change.
NATO ASI Series, Vol. I, 26, pp. 5–26.
Pilgrim, G.E., 1908. Geology of the Persian Gulf and adjoining
portions of Persia and Arabia. Memoir Geological Survey of India
34 (4), 1–179.
Pugh, J.M., 1997. The Quaternary desert sediments of the Al Liwa
area, Abu Dhabi. Unpublished. Ph.D. Thesis, University of
Aberdeen, 316pp.
Sanlaville, P., 1992a. Changements climatiques dans la p!eninsule
arabique durant le Pl!eistoc"ene sup!erieure et l’Holoc"ene. Pal!eorient
18, 5–26.
Sanlaville, P., 1992b. Paleoenvironment in the Arabian peninsula
during the upper Pleistocene and the Holocene (Preprint).
International Symposium on Evolution of Deserts (IGCP-252),
Ahmedabad.
Sarnthein, M., 1972. Sediments and history of the postglacial
transgression in the Persian Gulf and northwest Gulf of Oman.
Marine Geology 12, 245–266.
Sarnthein, M., 1978. Sand deserts during glacial maximum and
climatic optimum. Nature 272, 43–46.
Shackleton, N.J., 1987. Oxygen isotopes, ice volume and sea level.
Quaternary Science Review 6, 183–190.
Singhvi, A.K., Kar, A. (Eds.), 1992. Thar Desert in Rajasthan: land,
man and environment. Geological Society of India, Bangalore,
191pp.
Singhvi, A.K., Sharma, Y.P., Agrawal, D.P., 1982. Thermoluminescence dating of sand dunes in Rajasthan, India. Nature 295,
313–315.
Sirocko, F., 1994. Abrupt change in monsoonal climate: evidence from
geochemical composition of Arabian Sea sediments. Ph.D. Thesis.
Mathem-Naturwissensch Facultat der Christian-Albrechts-University, Kiel.
.
Sirocko, F., Garbe-Schonberg,
D., McIntyre, A., Molfino, B., 1996.
Teleconnections between the subtropical monsoons and highlatitude climates during the last deglaciation. Science 272,
526–529.
Teller, J.T., Glennie, K., Lancaster, N., Singhvi, A., 2000. Calcareous
dunes of the United Arab Emirates and Noah’s Flood: the postglacial reflooding of the Persian Gulf. Quaternary International
68–71, 297–308.
United Arab Emirates University, 1993. National Atlas of the United
Arab Emirates, Al Ain, UAE University.
Weyhenmeyer, C.E., Burns, S.J., Waber, H.N., Aeschbach-Hertig, W.,
Kipfer, R., Loosli, H.H., Matter, A., 2000. Cool glacial temperatures and changes in moisture source recorded in Oman groundwaters. Science 287, 842–845.
Wintle, A.G., 1993. Luminescence dating of aeolian sands: an
overview. In: Pye, K. (Ed.), The Dynamics and Environmental
Context of Aeolian Sedimentary Systems. Geological Society
London Special Publication, Vol. 72, pp. 49–58.
Wood, W., Imes, J., 1995. How wet is wet? Precipitation constraints on
late Quaternary climate in the southern Arabian Peninsula. Journal
of Hydrology 164, 263–268.
Yan, Z., Petit-Maire, N., 1994. The last 140 ka in the Afro-Asian arid/
semi-arid transitional zone. Palaeogeography, Palaeoclimatology,
Palaeoecology 110, 217–233.