Journal of Earth Sciences and Geotechnical Engineering, Vol.10, No.4, 2020, 87-110
ISSN: 1792-9040 (print version), 1792-9660 (online)
Scientific Press International Limited

Sea Level Changes in the Mesopotamian Plain and
Limits of the Arabian Gulf:
A Critical Review
Varoujan K. Sissakian1,2 Nasrat Adamo3
Nadhir Al-Ansari4, Mukhalad Abdullah5 and Jan Laue6

Abstract
The Mesopotamian Plain is a vast almost flat plain which descends in elevation
towards southeast until it reaches the sea level along the Gulf shore. The plain
covers the central part of Iraq; it is covered totally by different type of Quaternary
sediments. Among those sediments, the fluvial flood plain sediments of the Tigris
and Euphrates rivers with their distributaries are the most prevailing. The two rivermerge together to form the Shatt (River) Al-Arab which drains into the Gulf. The
extensions of the Gulf are a matter of debit, especially between two groups ofresearchers: geologists and archeologists and even within the same group. We havepresented different opinions which have dealt with the Gulf extensions, since thebeginning of the last century and until most recent studies. From the presented anddiscussed data, it is clear that there is no clear and sound data which confirms theactual extensions of the Gulf during Holocene and even Late Pleistocene.
Keywords: Arabian (Persian) Gulf; Pleistocene; Holocene; Sea level changes.

1

Lecturer, University of Kurdistan Hewler
Private Consultant Geologist, Erbil
3
Consultant Dam Engineer, Sweden
4
Professor, Lulea University of Technology, Sweden
5
Private Engineer, Baghdad, Iraq
6
Professor, Lulea University of Technology, Sweden2

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1. Introduction
Mesopotamia is a historical region located in West Asia and situated within the
Tigris– Euphrates river system. In modern days, roughly corresponding to most of
Iraq, Kuwait, parts of Northern Saudi Arabia, the eastern parts of Syria, southeastern Turkey, and regions along the Turkish–Syrian and Iran – Iraq borders(Collon, 2011), see Figure 1.
Mesopotamia means "(Land) between two rivers" in the ancient Greek. The oldest
known occurrence of the name Mesopotamia dates to the 4th century BC, when it
was used to designate the land east of the Euphrates in north Syria (Finkelstien,1962). In modern times, it has been more generally applied to all the lands between
the Euphrates and the Tigris, thereby incorporating not only parts of Syria but also
almost all of Iraq and south-eastern Turkey (Foster and Polinger Foster, 2009). The
neighbouring steppes to the west of the Euphrates and the western part of the Zagros
Mountains are also often included under the wider term Mesopotamia (Canard,
2011, Wilkinson, 2000 and Mathews, 2000). A further distinction is usually madebetween Upper or Northern Mesopotamia and Lower or Southern Mesopotamia(Miquel et al., 2011). Upper Mesopotamia, is also known as the Jazira, which is thearea between the Euphrates and the Tigris from their sources down to Baghdad(Canard, 2011). Lower Mesopotamia is the area from Baghdad to the Persian Gulf
(Miquel, 2011). In modern scientific usage, the term Mesopotamia often has achronological connotation also. In modern Western historiography of the region,
the term "Mesopotamia" is usually used to designate the area from the beginning oftime, until the Muslim conquest in the 630s, with the Arabic names Iraq and Jazira
being used to describe the region after that event (Foster and Polinger Foster, 2009
and Bahrani, 1998).

Figure 1: Geographical extension of Mesopotamia(Internet data, Wikipedia, 2019).

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The Mesopotamian Plain; however, is differentiated, geographically, geologicallyand historically from Mesopotamia. The Mesopotamian Plain represents part of
Mesopotamia, and nowadays it represents the existing plain between the Tigris andEuphrates rivers, which is limited to south of Al-Fatha gorge in the north. The
alluvial plains along the Iraqi – Iranian borders in the east. From the west, it islimited by wadi Al-Tharthar and the eastern limits of the Western Desert; thenextending with the northern limits of the Southern Desert (almost parallel to theEuphrates River); forming the southern limits of the plain. From the southeast, it islimited by the upper reaches of the Arabian Gulf ( see Figure 2).
The majority of the published data about Mesopotamia is related to and concernedwith the historical data about different civilizations; since it was the cradle of these
civilizations. Therefore, the available published data is related to the late Holocene
Period (less than 10,000 years). The majority of the available data is related toirrigation canals, changing of the river courses, dams’ construction and flood
controls.
The age of the Mesopotamian Plain backs to the Pleistocene (2.558 Ma), andbecause the alluvial sediments of the plain are not concerned in oil explorations;
therefore, very limited data is available from the drilled oil wells, as well from thewater wells; since the water wells very rarely encounter the Pleistocene sediments.
Moreover, there is a large similarity between the alluvial sediments of the plain andthe underlying Pre-Quaternary sediments (Yacoub, 20117 a and b); especially,
when the Bai Hassan Formation underlies the Mesopotamian Plain sediments.

Figure 2: Tentative limits of the Mesopotamian Plain within the
Mesopotamia. (Limited by the red line).

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2. Sea level changes
One of the most significant and obscure subjects in the Mesopotamian Plain is thechanges of the sea level and the geographical location of the shore line of the
Arabian Gulf during the past history, especially during Pleistocene and Holocene.
Almost the majority of the available data about the sea level and the geographicallocation of the shore line of the Arabian Gulf are restricted to the Holocene rather
than the Pleistocene. This is attributed to the presence of enormous archaeological
data as far as the Mesopotamian Plain is concerned. Because the Mesopotamian
Plain was the cradle of civilizations; therefore, a lot of archaeological studies areavailable, not like the Pleistocene Period where archaeological data is very scarce.
Accordingly, the data is related to the indications of Neotectonic activities. These
data in turn are not clear and accurate as those of the archaeological data during the
Holocene.
We will introduce some significant data mentioned by different authors concerning
the sea level changes in the Mesopotamian Plain and the reconstructed shorelines
together with our comments.
─ de Morgan (1900): He mentioned that in 696 B.C. the head of the Arabian Gulf
was south – southwest of Shush, with the Tigris and Euphrates Rivers flowing into
it separately about 70 km apart. Moreover, he mentioned that in 325 B.C. thesediments carried down by the Karun River were debouching at Ahwaz, assuming
to have formed a chain of islands stretching southwest from Ahwaz right across thegulf, thus isolating a lake into which flowed the still separate Tigris and Euphrates
Rivers. He was the first to reconstruct the shore line of the Gulf, by assuming its
extension from Hit (along the Euphrates River) to Samarra (along the Tigris River)during the last phases of the Stone Age (about 8,000 – 5,000 years ago).
─ Woolley (1938): During his excavations at Ur from 1926 to 1929, discovered an
8-foot (2.42 m) bed of clean clay separating pottery and other remains of Sumerianage (About 2,000 years B.C.) from the relics of an older period. The bed of clay wascorrelated with the Sumerian history and legends, on which the story of Noah isbased. This explains one of the great puzzles of South Mesopotamian archaeology,
which was the sudden and complete disappearance of the painted pottery which at
one time seems to have been universally distributed southern sites. The older people
who made this painted pottery were wiped out by the flood and are thought to have
lived-in low-lying villages. The early Sumerians who survived the flood areconsidered dwellers, living at a level to which the flood waters did not reach. Afterthe flood, they were thought to have been able to develop uncontaminated lands,
and to advance northwards and occupy lands depopulated by the flood. Thus, theSumerians "who according to their traditions were originally settlers on the sea coastof the Arabian Gulf are found when history opens to be masters of the delta for a
distance of 360 km from the sea. The authors believe that the finding of Wooley(1938) is good evidence about the location of Ur as far as the shoreline of the gulf
is concerned.

Sea Level Changes in the Mesopotamian Plain and Limits of the Arabian Gulf:
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91─ Lloyd (1943): Showed that the head of the Gulf before 4,000 B.C. was about 108
km northwest of Baghdad, and in Sumerian times (about 2,500 – 2,000 years B.C.)
it was in the neighbourhood of Ur, 415 km farther southeast. The authors would liketo mention that the presented evidence indicates on the contrary that the head of the
Gulf may, at the dawn of revealed history had even been more seaward of its present
position.
─ Lees and Falcon (1952): They have presented geological evidence whichconflicts with archaeological reconstructions and it seems certain that the realcourse of geographical history has been far more complex than the archaeologists
have assumed. The most recent event has been, contrary to archaeological opinion
an advance of the head of the Arabian (Persian) Gulf and it is probable that such
advance has alternated with retreat throughout historic and prehistoric ages.
The archaeologists usually have assumed that there has been a gradual retreat of thesea to the southeast in the Mesopotamian Plain. This is attributed to normal
processes of delta formation, where the vast amount of silt carried down by the
Tigris, Euphrates and Karun rivers is supposed to have filled the Gulf gradually.
The general rise of the sea-level resulting from the melting of the great ice sheets at
the end of the Last Glacial Period (about 11.1 Ka, Walker et al., 2009) may haveamounted to about 90 m (Holmes, 1944). He has stated that the bottom of the
Arabian (Persian) Gulf must have been then a fertile plain, floored with alluvium
from the united waters of the Tigris and Euphrates Rivers. This assumption
coincides with historical evidence that the great Hor Al- Ham’mar marsh between
Ur and Basra only came into existence in about 600 A.D.
The rejuvenation of the Karun system was caused by a renewed subsidence of the
Mesopotamian Plain to the southwest, or by a tilting of the hill country (Inside Iran)to the northeast, or probably by a combination of both. Accordingly, the gradientsof the rivers were increased causing them to trench into the alluvial deposits which
had been accumulating during the still-stand period, and the alluvial plains on which
the Sassanian settlements remains (about 200 A.D.) are found were incised to adepth of 5.15 m. The rejuvenation of the rivers; however, is not certain to be entirely
post-Sassanian as these settlements may have been established after the rivers hadcommenced their downward cutting. But the main facts are that between about
3,000 B.C. and the present day there was first a build-up of the land surface bysedimentation to about 2.4 m, and that this was followed by an entrenchment of therivers by 5.15 m. The southwestern extension of the earlier plain has been removedby erosion and the remains of any earlier habitations on its surface or entombedwithin its silts have been scattered and lost.
─ Lambeck (1996), predicted the sea-level change in the Arabian (Persian) Gulf
since the time of the last maximum glaciation at about 18,000 years B.P. to exhibit
considerable spatial variability, because of the response of the Earth to glacial
unloading of the distant ice sheets and to the melt water loading of the Gulf itself
and the adjacent ocean. He constructed models for the glacio-hydro-isostatic effects
and compared them with observations of sea-level change and also reconstructed
the paleo shoreline of the Gulf ( see Figure 3). From the peak of the glaciation until

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about 14,000 years B.P., the Gulf was free of marine influence out to the edge of
the Biaban (Bubian) Shelf. By 14,000 years B.P., the Strait of Hormuz had opened
up as a narrow waterway and by about 12500 years ago the marine incursion into
the Central Basin had started. The Western Basin flooded about 1,000 years later.
Momentary still stands may have occurred during the Gulf flooding phase at about
11,300 and 10,500 years B.P. The present shoreline was reached shortly before
6,000 years ago and exceeded as relative sea level rose (l – 2) m above its present
level inundating the low-lying areas of lower Mesopotamia. These reconstructions
have implications for models of the evolution of the Euphrates – Tigris – Karundelta, as well as for the movements of people and the timing of the earliest
settlements in lower Mesopotamia. For example, the early Gulf floor would haveprovided a natural route for people moving westwards from regions from the eastof Iran from the late Palaeolithic to early Neolithic.
Figure 3 illustrates the components for the Arctic ice sheet model whose eustatic
contribution at the time of the last glacial maximum is 90m. The Antarctic eustatic
contribution is about 37 m making up a total eustatic change of 127m since the lastglacial maximum.

Figure 3: Reconstruction of the shore lines in the Arabian Gulf.
1 = 18,000 B.P., 2 = 12,000 B.P., 3 = 10,000 B.P., and 4 = 8,000 B.P. (After
Lambeck, 1996). (The enclosed blue areas define the max. limits of the lakes
that could form if filled to their sill levels. The blue – white areas define
shallow topographic depressions).

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─Aqrawi (2001): He studied the Tigris – Euphrates deltaic deposits, and concluded
that wet climate conditions prevailed due to this transgression to around 6,000 years
B.P., semi-arid during the regression between 6,000 – 4,000 years B.P., and arid
conditions since around 3,000 years B.P. until present.
During early Holocene, arid climate dominated the Mesopotamian Plain after a long
period of the wetter conditions of Pleistocene. Such a climatic change has resulted
in the formation of gypcrete occurring within the fluvial-plain muds. However, thesediments were highly admixed with coarser sandy deposits of playa and aeoliansources in the margins of the Western Desert, and with older reworked sands ofZagros foothills to the Northeast of Lower Mesopotamia.
During the mid-Holocene, marine invasion had occurred when the climate becamewetter as well, brackish-water marine sediments were deposited, overlying theprevious fluvial plain deposits. The deposition started with transitional sediments
over the older early Holocene gypcrete deposits signalling the marine transgression.
After about ,2000 years of maximum flooding there was the end of the marine
brackish-water deposition and signalling another climatic change towards a morearid setting around 4,000 years ago. These climatic conditions are still continuous
in the area and reflect the salt-covered fluvial plain deposits of these rivers.
However, marsh – lacustrine deposits and environments remained, covering somevast lowland parts of the fluvial plains but further inland to the north of the presentday northern Gulf coasts (Figures 4 and 5).
Complex implications of neotectonic activities, sea-level fluctuations anddifferential sedimentation rates in addition to the climatic changes during Holocene
have resulted in the formation and preservation of these unique marshlands, which
are still covering most parts of the ancient Tigris–Euphrates–Karun delta. On theother hand, the high contribution of Aeolian deposits within the Holocene deltaic
successions, particularly to the western parts occurred during the high aridity
periods, which is still continuous. This contribution increased to form up to one
third of the sediments accumulated in the region after the domination of more severe
dry conditions and an arid climate from about 5,000–4,000 years B.P. It is worth
mentioning that the highest Aeolian contribution occurred through the advance ofsand dunes and storms (Aqrawi, 1995). Almost pure aeolian sands of a 0.5 m were
found in the western side boreholes which referenced to about 5,000 –5,500 years
B.P.
The decline in the rain precipitation had caused dramatic change in the climate, andhas resulted in the reduction in sediment load and the discharge of the Tigris andEuphrates rivers, consequently, reducing the sedimentation rates to less than
0.5m/1,000 years during the last 3,000 years B.P. As a result, most of the sediments
reaching the northern parts of the Gulf since then are believed to be transported by
the Karun River; rather than the Shatt Al-Arab (i.e. Tigris and Euphrates Rivers).
The Shatt Al-Arab was developed in very late Holocene, most probably during theAbbasid Era (Aqrawi, 1993), and followed the ancient channel of the Tigris River,at the confluence with the Euphrates River at Qurnah Town.

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Figure 4: Schematic cross-sections showing various periods of the Holocene
evolution of the Tigris–Euphrates delta when various climatic conditions
were dominant (After Aqrawi, 2001).

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Figure 5: Selected archaeological maps of southern Mesopotamia (adaptedfrom Geographical Handbook of Iraq and Persian Gulf, 1944) showing thehistorical changes in the northern shorelines of the Gulf. (From Aqrawi,2001).

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─ Tanoli (2013): Variations in sea level are caused by a combination of eustatic,
isostatic, and tectonic factors (Anzidei et al. 2011; Lambeck et al. 2011) and therelation between rate of base level change and the sedimentation rate (Catuneanu etal. 2009). Melting of ice after the last ice age of Late Pleistocene has contributed toadditional land-locked water to the sea, resulting in an overall sea level rise during
the Holocene. The removal of large ice sheets has readjusted the Earth’s crust due
to change in gravitational potential in higher latitudes (Lambeck 1996).
Since the last glacial maximum around 18,000 years ago, as a consequence ofmelting of the ice sheets, unlocked water resulted in sea level rise. Generally, thissea level rise was initially fast, slowing to very slow rate afterward from around
7,000 years B.P. Prior to this global sea level rise, it is widely recognized that theArabian Gulf was a dry valley (Lambeck, 1996) through which the Euphrates –Tigris Rivers flowed (McIntosh, 2005) and their deltas might have emptied into theGulf of Oman (Biot report #422, 2007, from Nutzel, 1979) (Figure 6).
The present average depth of the Gulf is around 46 m, with maximum depth around82m (Biot report #422, 2007, from Nutzel, 1979). From the glaciation peak until
14,000 years B.P., the Gulf was free of marine influence (Lambeck, 1996). Around
14,000 years B.P., the Strait of Hormuz opened as a narrow waterway, and by
12,500 years B.P., the central basin had started experiencing marine incursion(Lambeck, 1996). The sea transgressed at an average rate of (100 – 120)m per year
across the floor of the Arabian Gulf (Sarnthein, 1972), based on estimates of the
distance covered by the transgressed waters from the Strait of Hormuz to the mouthof the Euphrates –Tigris. Transgression over this distance, about 1,000 km, tookapproximately 7,000 years, between 13,000 and 6,000 years B.P. Kassler (1973)
has suggested fluctuating sea level rise in the gulf floor with relatively rapid rises
occurring between 12,000 and 11,000 years B.P., 9,500 – 8,500 years B.P., andaround 7,000 years B.P.

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Figure 6: Arabian Gulf Portrayal circa 14,000 years B.P. The lower part of
the Gulf is first flooded at about 13,000 years B.P., but large freshwater lakes
could have developed in several locations within the valley floor. Largeshallow depressions also occur on the southern margin of the present gulf
(After Tanoli, 2013).
The Holocene sea level peaked at around 5,500 years ago and stood about (1–2) mhigher than the present level in the southern Arabian Gulf (Williams and Walkden,
2002). However, Evans et al. (2002) from their study in coastal Abu Dhabi put thepeak transgression time around 4,500 years B.P., and similarly Evans (2011), put it
around 5,000 – 4,000 years B.P. The sea level stood about 3 m higher than thepresent-day level in the northern Gulf (SEMP, Biot report 422 2007), resulting in
sea incursion within the hinterland of southern Iraq up to Amara and Nasiriya cities,some 200 km north of the current shorelines of Iraq and Kuwait (Aqrawi, 1995). In
eastern Saudi Arabia, Holocene deposits close to the shoreline are 3 m higher thanthe present-day highwater mark (McClure and Vita-Finzi, 1982). Carbon-14 isotope
age dating of the mollusk shells has yielded an age of 3,700 – 6,000 years B.P. forthese deposits, confirming this sea level high.
─ Al-Sheikhly et al. (2013): They reconstructed the shore line of the Arabian Gulf
depending on the ostracoda and foraminifera assemblages as ecological indicatorsand concluded that the Southern Mesopotamia effected by three distinguished sea
transgressions; the first was during the time interval 22,000 – 20,000 years B.P.
(Figure 7), represented by deltaic environment which coincides with the marinetransgression and is correlated with a period of humidity and sea level rise during
Late Pleistocene (37,000 – 20,000 years B.P.). The second transgression registeredduring the time interval 16,000 – 14,000 years B.P., it is distinguished by deltaic
environment and marine environment. The closure of Würm Glacial Cycle at 16,000
years B.P., which was distinguished by global climatic changes toward warmer

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conditions, and was registered by the distribution of fresh water- fluvial and backswamps environments in Southern Mesopotamia during the time interval 13,000 –
11,000 years B.P (Figure 7). So, by the end of Pleistocene (11,800 years B.P.) thethird sea transgression was recorded by the presence of deltaic and shoal backswamps environments. This transgression continued during 9,000 years B.P. andrepresented by the deltaic environment, in addition to the back swamps and fluvial
environments where the climate was wet with low temperature. The influence of thethird transgression continued during the time interval 8,000 -7,000 years B.P. in
addition to the distribution of back swamps and fresh water – fluvial environments.
During the interval 7,000 – 6,000 years B.P., the fresh water fluvial environment
prevailed indicating an ancient river which coincides with the assumption of Adams
and Nissen (1975) about the presence of a river during Ubaid Period (7,000 – 6,000
years B.P.). This also coincides with the presence of the Ancient Cities of Sipper,
Kutha and Kish (Figure 8) which were lying on this river (Sousa, 1983). Thisancient river might be a branch of the Euphrates River, called by the archaeologists
as Arahtu River (Sousa, 1963).
During 6,000 – 5,000 years B.P. (Figure 7), the Post-Glacial Climatic Optimum
occurred, where the sea level and humidity were changed worldwide. So, the Back
Swamps environment was prevailed over the Southern Mesopotamia during 5,500– 4,500 years B.P.
By the end of 5,000 years B.P., the Climate was cold and wet (Weiss et al., 1993),
and that is recorded in Southern Mesopotamia by increasing rain fall and wideningof rivers during 4,000 – 3,000 years B.P. Nützel (1975) mentioned that that there
was a decrease in temperature (2 – 3 degrees) in Southern Mesopotamia during3,500 years B.P., causing colder climate and rising of sea level (3 meters above
nowadays level).

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Figure 7: Four maps showing the extensions of deltas (in green), the shore
line (in blue) and old traces of the rivers (in dashed red lines). A) 22,000 –
20,000 Years, B) 13,000 – 11,000 Years, C) 6,000 – 5,000 Years, and D)1,000
Years (Modified from Al-Sheikhly et al., 2017).
Throughout the time interval 3,500 – 3,000 years B.P., the fresh water fluvial
environment was prevailing. The fresh water environment may indicate thechanging of the Euphrates River to its present course during that time, or there wasa bifurcation of the Euphrates River at that site. Sousa (1963) mentioned that theAncient Euphrates River had changed its course westwards during the Babylonian
Period from Kutha Ancient City towards Babylon river. This was due to a dam
construction to raise the water levels which in turn led to prosperity of Babylon
Civilization at that time. But the Euphrates River had changed its course tectonicallybecause of the effect of Falluja Subsurface Structure (Al-Sakiny, 1993).

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Figure 8: Major archaeological sites of Mesopotamian Plain with surveyed
areas (serial numbers) and hypothetical extent of the Arabian Gulf ca. 4,000
B.C. 1) Diyala, 2) Akkad, 3) Kish, 4) Nippur, 5) Mashkan-Shapir, 6) Warka(Uruk), 7) Uruk), 8) East Ghrraf, 9) Tello Region, 10) Lagash, 11) Zurghal(Nina-Sirara), 12) UR-Eridy, 13) Hammar Lake. (After Pournelle, 2013).

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3. Discussion
The main topic which needs discussion in the current work is the extensions of the
Gulf coast during different times and the changes in the river courses. We haveselected randomly few authors and summarized their results of the coast lines inTable 1. From reviewing the data presented in Table 1, it is clear that there is almost
no any agreement between the selected authors as the extension of the coast line isconcerned. It is very difficult to explain these extreme variations in thereconstructed coast lines. However, we believe that the main reason is the used datain their claims and how neat are the results. As the dating is the main significant
item which plays the main role in reconstruction of the coast lines; therefore, thedating is still a main problem in considering its accuracy. This depends on manyfactors which are beyond the scope of the current study.
The dating procedure of the events is quite different between the assumptions ofarcheologists and geologists. The archeologists usually consider retreatment of thecoast line of the Gulf due to continuous sedimentation and delta development by
the Tigris and Euphrates rivers. Whereas, geologists adopt the melting of great ice
sheets after the last glaciation period as their criterion (Lees and Falcon, 1952).
Therefore, the assumptions of the selected authors are not in agreement with eachother.
There are some discrepancies in the assumptions, even in the works of the sameauthors. For example, De Morgan (1900) assumes that the shoreline was near Hit;along the Euphrates River and at Samarra; along the Tigris River during 8,000 –
6,000 B.C., which are about 600 km northwest and north of the present shoreline.
Moreover, he assumes that the Tigris and Euphrates rivers were flowing directly
into the gulf without being merged together during 325 B.C. This means that theshoreline was more northwards than the present shoreline; otherwise, the two rivers
couldn’t flow separately into the Gulf. But, he didn’t mention how far the shoreline
was. It is worth to mention that before 8,000 years the Ubaid settlements were close
to the location of Ur (Figure 8) which was very near from the shoreline (Carter andPhilip, 2010).
The time of reaching the present shoreline location is again quite different from thementioned assumptions by different authors (Table 1). For example, Lambeck(1996) claimed the present shoreline location was 6,000 B.C. Whereas, during 6,000
B.C. the shoreline was 360 km north of the present location according to Wolley(1939), and between Nasiriya and Amara (Tanoli, 2013, Al-Sheikhly et al., 2013,
and Pournella, 2013). Moreover, Lambeck (1996) claimed that before reaching to
the present shoreline, the whole Gulf was dry and the Tigris and Euphrates River
were flowing into the Gulf directly. This assumption was confirmed only by
Tanoli (2013). However, this agrees with the theory that the early Sumerians had
crossed the Gulf which was dry at that time coming from a place in Baluchistan andthey settled in Bahrain (Dilmun) before moving to Mesopotamia (Hamblin, 1987).
Tanoli (2013) claimed that until 14,000 B.C., the whole Gulf area was a dry land.
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reconstructed scenarios of different authors (Table 1).
Al-Ameri et al. (2000) mentioned that the shoreline of the Gulf was 1440 km
southeast of Baghdad before 10,500 B.C., and it was 250 km southeast of Baghdad
along the Tigris River (near Amara city) and 60 km southwest of Baghdad along
the Euphrates River (near Hilla city). Although they use palynological evidences
like their colleagues (Al-Sheikhly et a., 2013) but they reached to very different
results as the shoreline of the Gulf is concerned (Table 1).
Another abnormal assumption is presented by Al-Sheikhly et al. (2013). They
constructed the shoreline during different time spans depending on the present
ostracods and palynology. The abnormal presentation is that they extended theshoreline only along the Tigris River; not along the Euphrates River (Figure 7). Thismeans the course of the Euphrates River was higher than that of the Tigris River,therefore, the gulf extended only towards the Tigris River. Moreover, this meansthat the ancient city of Ur was never been located along a shoreline, which is not inaccordance with the majority of carried out archaeological and geological studies.
Another significant issue which needs discussion is the changing of the rivercourses during the Pleistocene and Holocene. There is a big difference between theconsidered reasons between the archaeological and geological studies. The
archaeological studied assume that all the happened changes in the river courses are
related to major floods and/ or constructed irrigation canals (Ellison, 1978).
Whereas, geological studies assume that the main reason for changing of the rivercourses is the Neotectonic activities which are mainly related to the growth of thesubsurface anticlines (Al-Sakiny, 1993, Fouad and Sissakian, 2012, Sissakian,
2013, Sissakian et al., 2017 and 2018). Moreover, the activity of the Abu Jir –Euphrates Active Fault Zone also has played role in shifting the course of theEuphrates River (Figure 9) and is still shifting the river course more towards
northeast. Some large alluvial fans also have shifted the river courses during their
growth, especially during Late Pleistocene and Holocene.

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Table 1: Generalized dating of the Gulf’s location based on the mentioned authors
No.

Authors

Sea level location during years B. C.
22,00018,000

1

16,00010,000

10,0008,000

8,0004,000

4,0001,000

Notes

De
MorganHit (along the
Euphrates

The Tigris
and(1900)

River) to Samarra(along the Tigris
River)

Euphrates
Rivers were
flowing tothegulf
separately
even in 325
B.C.

2

Woolley(1938)

360 kmnorth of thecurrent
location3

Lloyd

Near Ur(2,5002,000 B.C)
and 108 km
NW(1943)

Based on aclay bed, 2.4
m thick

Baghdad(4,000B.C.)
4Lees andThe gulfarea
was a
fertileplane

Falcon(1952)
5

Lambeck

The gulf was free from marine influence(1996)

6

Al-Ameriet al.,
2,000

1,440 kmsoutheastof
Baghdad

The present
shore line
reached(6,000years B.C.)

350 km south of Baghdad along the Tigris
River and
60 km southwest of Baghdad along the
Euphrates River

The Straightof Hurmuz
was opened
at 1250

104
7

Sissakian et al.
Aqrawi(2001)

8

Tanoli(2013)

9

AlSheikhly
et al.
(2013)

10

Pournelle(2013)

Near Amara along the Tigris River only

North of
Basra
110Km
(2,000 –1,200
B.C.), and
70 km(1,200800B.C),
70km southof Basra(1850(A.C.)

Shat Al-Arab
was formed

From
Amara toNasiriya

The Tigris
andEuphrates
River were
mergingsouth of
Kuwaitwithin thedry gulf area

From
Amara toNasiriya

Near Basra
before 1,000
years

between 750– 1260 A.D.

From
Amara toSamawaA good example is Al-Batin alluvial fan, which has shifted the course of theEuphrates River (Sissakian et al., 2014). However, the influence of major floods
and the mechanism of river hydraulics, especially during large floods are also
considered in majority of geological studies. The presence of main irrigation canals
which were constructed during early civilizations are also considered too ingeological studies as main factor which had contributed in shifting of the rivercourses (Williams, 2001, Ortega et al., 2014). The humid conditions associated withvery heavy rain showers during wet stages of the Pleistocene and even early
Holocene also had contributed in changing the river courses. This is attributed tothe erosional forces and the weight of the carried sediments in entrenching thecourses of the rivers into more straight courses, especially when acute meanders had
existed in the river courses, where the irrigation canals were constructed
perpendicularly on large meanders. This is called rapidly varied flow (Kindsvater,1958).

Sea Level Changes in the Mesopotamian Plain and Limits of the Arabian Gulf:
A Critical Review

105

Figure 9: Satellite image showing abandoned river course (AR) of theEuphrates River. Note Al-Slaiabt Depression (SD) which was most probably
an old marsh.

4. Conclusions
Our main conclusions deal with the extensions of the shoreline of the Gulf and thechanges of the river courses. For the shoreline extensions, it is very clear fromalmost all the carried-out works including geological and archaeological ones that
there is no agreement between the given extensions of the shorelines during
different periods. However, geologists do believe that the Gulf was a dry area andwas filled due to melting of huge amounts of ice; accordingly, the shoreline started
progressing landwards. After that, due to climate change, the shoreline started
retreating downwards due to the delta development of the Tigris, Euphrates andKarun rivers.
This scenario is not accepted by archeologists who believe that the shoreline wasalways retreating downwards due to delta development. The second main
conclusion deals with the changes of the river courses. We do believe that the
majority of the rivers have changed their courses due to the growth of subsurface
anticlines in different parts of the Mesopotamian Plain, and the growth is stillongoing. However, the role of the major floods and the constructed irrigation canals
have played a big role in changing the river courses as they contributed with the
Neotectonic forces represented by the growth of the subsurface anticlines.

106

Sissakian et al.

Acknowledgment
The authors express their sincere thanks to Mohammed Al-Azzawi (Iraq Geological
Survey, Baghdad) for supplying the satellite images and to Mr. Maher Zaini (Iraq
Geological Survey, Baghdad) for conducting some of the enclosed figures.

References[1] Adams, M. R. and Nissen, H. (1975). The Uruk Countryside. The Natural
setting of Urban Societies, pp. 35 – 39, Figure 17. University of Chicago Press.
[2] Al-Ameri, T., Al-Joburi, B. and Al-Dulaimy, A. (2000). Palynologicalevidences for events of the historical Deluge on Mesopotamian peoples andthe Future climate change. 5th Intern. Conf. on the Geology of the Arab World,
Cairo University, pp. 1575 – 1584.
[3] Al-Badri, A., Ahmed, A. and Seryoka, S. (1984). Final report on the Samawa
salt deposits, Muthana Governorate. Iraq Geological Survey Library Report
No. 1510.
[4] Al-Jiburi, H.K. and Al-Basrawi, N. H. (2011). Hydrogeology of the
Mesopotamian Plain. Iraqi Bulletin of Geology and Mining, Special Issue No.
4, pp. 83 – 103.
[5] Al-Mubarak, M.A. and Amin, R.M. (1983). The regional geological mappingof the western part of the Southern Desert and the eastern part of the Western
Desert. Iraq Geological Survey Library Report No. 1380.
[6] Al-Kadhimi, J.M.A., Sissakian, V.K., Fattah, A.S. and Deikran, D.B. (1996).
Tectonic Map of Iraq, scale 1:1,000,000, 2nd edit., Iraq Geological Survey
Publication, Baghdad, Iraq. Journal of Science, 2017, Vol. 58, No. 4A, pp.
1856 – 1873.
[7] Al-Sakini, J.A. (1993). New look on the history of old Tigris and Euphrates
Rivers, in the light of Geological Evidences, Recent Archaeological
Discoveries and Historical Sources. Oil Exploration Co. Baghdad, Iraq, p. 93(in Arabic).
[8] Alsharhan, A.S. and Nairn, A.E.M. (1997). Sedimentary Basins and Petroleum
Geology of the Middle East. Elsevier, Amsterdam, p. 811.
[9] Al-Sheikhly, S.S., Al-Jumaily, W.A., Al-Ka'abi, F.S., Al-Shehmany, Z.Kh.
and Owen, M.O. (2017). Late Pleistocene – Holocene Paleoecology ofSouthern Mesopotamia, Iraq.
[10] Bahrani, Z. (1998). Conjuring Mesopotamia: Imaginative Geography a World
Past. In: Meskell, L., Archaeology under Fire: Nationalism, Politics andHeritage in the Eastern Mediterranean and Middle East, London: Routledge,
pp. 159–174. ISBN 978-0-41519655-0.
[11] Berberian, M. (1995). Master "blind" thrust faults hidden under the Zagros
folds: active basement tectonics and surface morphotectonic. Tectonophysics,
241, pp. 193 – 224.

Sea Level Changes in the Mesopotamian Plain and Limits of the Arabian Gulf:
A Critical Review

107[12] Bhattacharya, S., Virdi, N.S. and Philip, G. (2005). Neotectonic activity in theouter Himalaya of Himacgal Pradesh and around Paonta Sahib: A
morphotectonic approach. Wadia Institute of Himalayan Geology, Dehra Dun– 248 001, India.
[13] Buday, T. (1980). The Regional Geology of Iraq. Vol.1: Stratigraphy andPaleogeography. In: I.I., Kassab and S.Z., Jassim (Eds.). Iraq Geological
Survey Publications, Baghdad, Iraq, p.445.
[14] Buday, T. and Jassim, S.Z. (1984). Tectonic Map of Iraq, scale 1:1,000,000.
Iraq Geological Survey Publications, Baghdad Iraq.
[15] Buday, T. and Jassim, S.Z. (1987). The Regional Geology of Iraq. Vol. 2.
Tectonism, Magmatism and Metamorphism. In: M.J., Abbas and I.I., Kassab(Eds.). Iraq Geological Survey Publications, Baghdad, p. 352.
[16] Canard, M. (2011). "Al-ḎJazīra, Ḏjazīrat Aḳūr or Iḳlīm Aḳūr". In: Bearman,
P., Bianquis, Th., Bosworth, C.E., van Donzel, E. and Heinrichs, W.P.
Encyclopaedia of Islam, 2nd edition. Leiden: Brill Online, OCLC 624382576.
[17] Carter, R.A. and Philip, G. (2010). Beyond the Ubaid: Transformation andIntegration in the Late Prehistoric Societies of the Middle East (Studies inAncient Oriental Civilization, Number 63) The Oriental Institute of the
University of Chicago (2010) ISBN 978-1885923-66-0 p.
[18] Collon, D. (2011). Mesopotamia. BBC, Ancient History in Depth.
http://www.bbc.co.uk/history/ancient/cultures/mesopotamia_gallery.shtml.
[19] De Morgan, J. (1900). Delegation en Perse, Memoires, Paris. Tome I, pp. 4 –48.
[20] Ditmar, V. (1971). Geological conditions and hydrocarbon prospect of the
Republic of Iraq (Northern and Central parts). Technoexport report, OEC
Library, Baghdad, Iraq.
[21] Dunnington, H.V. (1958). Generation, migration, accumulation anddissipation of oil in Northern Iraq. In: G.L. Weeks (Ed.), Habitat of Oil, a
Symposium. AAPG, Tulsa.
[22] Finkelstein, J.J. (1962). "Mesopotamia", Journal of Near Eastern Studies, 21(2), pp. 73 – 92. doi:10.1086/371676, JSTOR 543884.
[23] Fouad, S.F. (2010). Tectonic evolution of the Mesopotamia Foredeep in Iraq.
Iraqi Bulletin of Geology and Mining, Vol. 6, No. 2.
[24] Fouad, S.F. (2012). Tectonic Map of Iraq, scale 1:1,000,000, 3rd edition. Iraq
Geological Survey Publications, Baghdad, Iraq.
[25] Fouad, S.F. and Sissakian, V.K. (2011). Tectonic and Structural Evolution of
the Mesopotamia Plain. Iraqi Bulletin of Geology and Mining, Special Issue
No. 4, pp. 33 – 46.
[26] Foster, B. R. and Polinger Foster, K. (2009). Civilizations of Ancient Iraq,
Princeton: Princeton University Press. ISBN 978-0-691-13722-3.
[27] Hamblin, D.J. (1987). Has the Garden of Eden been located at last?
Smithsonian Magazine, Volume 18. No. 2.

108

Sissakian et al.

[28] Hessami, K., Koyi, H.A., Talbot, G.J., Tabasi, H. and Shalanian, E. (2001).
Progressive unconformities within an evoluting foreland fold – thrust belt,
Zagros Mountains. Jour. Geol. Soc., 158, pp. 969 – 981.
[29] Holmes, A. (1944). Principles of physical geology. Thomas Nelson and Sons
Ltd. London, p. 638.
[30] ICS (International Commission on Stratigraphy) (2012). International
Chronological Chart. Brisbane, Australia, IGC 34.
[31] Iraqi-Soviet Team (1979). Geological conditions and hydrocarbon prospectsof the Republic of Iraq. INOC Library, Baghdad, Iraq.
[32] I.S.C.P. (1984). Iraqi standard specification No. 5/ 1984, Portland Cement.
Baghdad, Iraq. www.sciepub.com/reference/124723.
[33] Jassim, S.Z. (1981). Early Pleistocene Gravel Fan of the Tigris River from AlFatha to Baghdad, Central Iraq. Journal of Geological Society of Iraq, Vol. 14,
pp. 25 – 34.
[34] Jassim, R.Z. (1997). Mineralogy, Geochemistry and origin of Shari Saltern.
Unpublished Ph.D. Thesis, University of Baghdad.
[35] Jassim, S.Z., Karim, S.A., Basi, M.A., Al-Mubarak, M. and Munir, J. (1984).
Final report on the regional geological survey of Iraq, Vol. 3, Stratigraphy. Iraq
Geological Survey Library Report No. 1447.
[36] Jassim, S.Z., Hagopian, D.H. and Al-Hashimi, H.A. (1986). Geological Mapof Iraq, scale 1:1,000,000. Iraq Geological Survey Publications, Baghdad, Iraq.
[37] Jassim, S.Z., Hagopian, D.H. and Al-Hashimi, H.A. (1990). Geological Mapof Iraq, scale 1:1,000,000, 2nd edition. Iraq Geological Survey Publications,
Baghdad, Iraq.
[38] Jones, S.J. and Arzani, A. (2005). Alluvial fan response times to tectonic andclimatic driven processes: Example from the Khrud mountain belt.
Geophysical Research Abstracts, Vol. 7. European Geosciences Union.
[39] Judicial Watch (2002). Maps and charts of Iraqi Oil Fields.
www.judicialwatch.org/maps-andcharts-of-iraqi.
[40] Lambeck, K. (1996). Shoreline reconstructions for the Persian Gulf since thelast glacial maximum Earth and Planetary Science Letters, Vol. 142, pp. 43 –
57.
[41] Lees, G.M. and Falcon, N.L. (1952). The Geographical History of the
Mesopotamian Plains. The Geographical Journal, Vol. 118, No. 1 (Mar.,
1952), pp. 24 – 39.
[42] Lloyd, S. (1943). Twin rivers. A brief history of Iraq from the earliest time tothepresentday.
OxfordUniversity
Press,
p.
251.
https://archive.org/details/in.ernet.dli.2015.61071.
[43] Kindsvater, C.E. (1958). River Hydraulics. Geological Survey Water-Supply
Paper 1369-A. United States Government Printing Office, Washington.
[44] Koster, E.A. (2005). The Physical Geology of Western Europe, Chapter 2:
Neotectonics. Oxford University Press, p. 472.

Sea Level Changes in the Mesopotamian Plain and Limits of the Arabian Gulf:
A Critical Review

109[45] Kumanan, C.J. (2001). Remote sensing revealed morphotectonic anomalies asa tool to neotectonic mapping, experience from south India. Centre for Remote
Imaging, Sensing and Processing, Singapore.
[46] Markovic, M., Pavlovic, R., Cupkovic, T. and Zivkovic, P. (1996). Structural
Pattern and Neotectonic activity in the wider Majdanpek area, NE Serbia,
Yugoslavia. Acta Montanistica Slovaca, Rocnik 1, pp. 151 – 158.
[47] Matthews, R. (2003). The Archaeology of Mesopotamia. Theories andApproaches, Approaching the past, Milton Square: Routledge, ISBN 0-41525317-9.
[48] Mello, C.L., Metelo, C.M.S., Suguio, K. and Kohler, C.H. (1999). Quaternary
sedimentation, neotectonics and evolution of the Doce river middle valley lakesystem (SE Brazil). Revista do Instituto Geologico, IG Sao Paulo, Vol. 20, No.
1/2, pp. 29 – 36.
[49] Miquel, A., Brice, W.C., Sourdel, D., Aubin, J., Holt, P.M., Kelidar, A., Blanc,
H., MacKenzie, D.N. and Pellat, Ch. (2011). "ʿIrāḳ". In: Bearman, P.,
Bianquis, Th., Bosworth, C.E., van Donzel, E., Heinrichs, W.P.,
Encyclopaedia of Islam, 2nd edit. Leiden: Brill Online, OCLC 624382576.
[50] Nutzel, W. (1979). On the geographical position of as yet unexplored early
Mesopotamian cultures: contribution to the theoretical archaeology. Journal
American Orient. Soc., Vol. 99, No. 2, pp. 288 – 296.
[51] Ortega, J.A., Razola, L. and Garzón, G. (2014). Recent human impacts andchange in dynamics and morphology of ephemeral rivers. National Hazards
Earth Syst, Vol.14, Issue 3, pp. 713 – 730. https://doi.org/10.5194/nhess-14713-2014, 2014.
[52] Philip, G. and Virdi, N.S. (2007). Active faults and neotectonic activity in the
Pinjaur Dun, NW Frontal Himalaya. Wadia Institute of Himalayan Geology,
33, Gen., Dehra Dun – 248 001, India.
[53] Pournelle, J.R. (2013). Marshland of Cities: Deltaic Landscapes and the
Evolution of Civilization.
[54] Sissakian, V.K. (2013). Geological evolution of the Iraqi Mesopotamia
Foredeep and Inner Platform, and near surrounding areas of the Arabian Plate.
Journal of Asian Earth Sciences, 72 (2013) pp. 152–163, Elsevier Publication,
Journal homepage: www.elsevier.com/locate/jeseas.
[55] Sissakian, V.K. and Deikran, D.B. (1998). Neotectonic Map of Iraq, scale
1:1,000,000. Iraq Geological Survey Publications, Baghdad, Iraq.
[56] Sissakian, V.K. and Fouad, S.F. (2012). Geological Map of Iraq, scale
1:1,000,000, 4th edition. Iraq Geological Survey Publications, Baghdad, Iraq.
www.iasj.net/iasj?func=fulltext&aId=99666[57] Sissakian, V.K. and Abdul Jab’bar, M.F. (2013). Alluvial Fans of the
Hab'bariyah Depression, Iraqi Western Desert. Iraqi Bulletin of Geology andMining 9, No. 2, pp. 27 – 45.
[58] Sissakian, V.K., Al-Ansari, N. and Knutson, S. (2013). Sand and dust storm
events in Iraq. Natural Science, Vol.5, No. 10, pp. 1084–1094.
http://dx.doi.org/10.4236/ns.2013.510133

110

Sissakian et al.

[59] Sissakian, V.K. Shihab, A.T., Al-Ansari, N. and Knutsson, S. (2014). Al-Batin
Alluvial Fan, Southern Iraq. Engineering, 2014, Vol. 6, p. 699 – 711. Published
online, October, 28, 2014 in SciRes. http://www.scirp.org/journal/ eng.
http://dx.doi.org/10.4236/3ng.2014.61
1069.
DOI:
10.4236/eng.2014.611069.
[60] Sissakian, V.K., Shehab, A.T., Al-Ansari, N. and Knutson, S. (2017). New
Tectonic Findings and its Implication on Locating Oil Fields in Parts of Gulf
Region. Journal of Earth Sciences and Geotechnical Engineering, Vol. 7, No.
3, 2017, pp. 51 – 75. ISSN: 1792-9040 (print version), 1792-9660 (online),
Scienpress Ltd.
[61] Sissakian, V.K., Abdul Ahadb, A.D., Al-Ansari, N. and S. Knutsson, S. (2018).
Neotectonic Activity from the Upper Reaches of the Arabian Gulf andPossibilities of New Oil Fields. Geotectonics, Vol. 52, No. 2, pp. 240–250.
[62] Sousa, A. (1963). The Floods of Baghdad in History, Dar Al-Adib Press,
Baghdad (in Arabic).
[63] Sousa, A. (1983). History of Mesopotamian civilization in the light ofirrigation agricultural projects: Recent archaeological discoveries andhistorical sources. Al-Huriya Printing House, Baghdad, Iraq.
[64] Tanoli, S.K. (2014). Sedimentological evidence for the Late Holocene sea
level change at the Enjefa Beach exposures of Kuwait, NW Arabian Gulf.
Arabian Journal of Geosciences, Vol. 8, No.8, pp. 1 – 14.
[65] Walker, M., Johnsen, S., Rasmussen, S.O., Popp, T., Steffensen, J.P., Gibbard,P., Hoek, W., Lowe, J., Andrews, J., Bjorck, S., Cwynar, L. C., Hughen, K.,
Kershaw, P., Kromer, B., Litt, T., Lowe, D. J., Nakagawa, T., Newnham, R.,
and Schwander, J. (2009). Formal definition and dating of the GSSP (Global
Stratotype Section and Point) for the base of the Holocene using the Greenland
NGRIP ice core, and selected auxiliary records. Journal Quaternary Science,Vol. 24, pp. 3 – 17. ISSN 0267-8179.
[66] Wilkinson, T. J. (2000). Regional Approaches to Mesopotamian Archaeology:
The Contribution of Archaeological Surveys. Journal of ArchaeologicalResearch, 8 (3): 219 – 267, doi:10.1023/A:1009487620969, ISSN 1573-7756.
[67] Woldai, T. and Dorjsuren, J. (2008). Application of remotely sensed data forneotectonic study in Western Mongolia. Commission VI, Working Group V.
Conference: ISPRS 2004: Proceedings of the XXth ISPRS Congress: Geoimagery bridging continents, Volume: Comm. VI WG VI/V. pp. 1192-1196.
[68] Williams, P.B. (2001). River Engineering Versus River Restoration. ASCE
Wetlands Engineering & River Restoration Conference, Reno, Nevada.
[69] Woolley, L. (1938). Ur of the Chaldees. Pelican Books, pp. 18 – 21.
[70] Yacoub, S.Y. (2011a). Geomorphology of the Mesopotamia Plain. Iraqi
Bulletin of Geology and Mining, Special Issue No. 4, pp. 7 – 32.
[71] Yacoub, S.Y. (2011b). Stratigraphy of the Mesopotamia Plain. Iraqi Bulletinof Geology and Mining, Special Issue No. 4, pp. 47 – 82.