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The Mesopotamian Geomorphology researches..
Articles
Geomorphology of Mesopotamia
Abdul-Mutalib H. Al-Marsoumi*
College of Science, Basrah University, Basrah-Iraq
Mesopotamia is a flat plain
slopping gently from NW to SW covered with recent
sediments of fluvial and Aeolian origin. In general the
Mesopotamian plain is considered as synclinorium with
continuous subsidence to accommodate the huge amount of
sediments that contributed annually by Tigris and
Euphrates Rivers. based on the fluviolacustrine and
partly marine basinal sediments, the Quaternary of
Mesopotamia plain is built up by fluviatile gravels and
large outwash fans, developed along the margins of the
region.
Mesopotamian plain usually
covered with Quaternary heterogonous sediments of both
ages Pleistocene and Holocene. The stratigraphic column
composed mainly of sand, silt, and clay beds with good
porosity and variable thickness. No continuous
stratigraphic sequence of quaternary can be supposed,
and many lithological facies replacing each other
horizontally and vertically. There are several types of
recent sediments have been recognized; Flood plain,
Shallow depression filling, Ephemeral valley filling ,
deposit of ancient irrigation canals, and Aeolian
deposits (sand dunes and sheets). The total thickness
of Quaternary sediments varies from few meters near the
boundary with the stable shelf to the west to more than
100 m to the near the Iraqi- Iranian boundaries to the
northeast (Mandili area).
The climate of Iraq is
subtropical, continental, arid climate with dry hot
Summer and cooler Winter, with some rainfall in central
and southern Iraq, and more rainfall in the northern
part of the country. The winter is characterized by high
pressure, the summer by low pressure. The grater part of
the country has a real desert climate. Rainfall is very
low and a large portion of the rain water evaporates
immediately. The annual precipitation ranges between
133mm in Basrah to 160 mm north Baghdad. In reality the
amount of water available for plant growth soil
formation is much smaller than is indicated by
precipitation data. The influence of Arabian Gulf on
Iraqi climate is very limited. Near the Gulf the
relative humidity is higher than in other parts of Iraq.
The northwest wind are common in Iraq, the presence of
wind deflation areas aids in the development of many
sand dunes areas (Afaj, Tel-Laham, and umm Qaser).
The dominant arid climate,
low rainfall, wide distribution of geologic formation
containing salt, and the bad irrigation systems brought
about the saline soils of both shura and sabkha types.
The latter type is very common in Basrah area. Of both
coastal and inland types.
Regarding Basrah area,
Jabal sanam form the main prominent geomorphlogical
feature, it is elevated 152 m above sea level, it is
believed that jabal sanam resulted from salt tectonisms.
Moreover, the Basrah governorates characterized by the
following geomorphic units; Tidal flats, Marshes and
swamps deposits, sand dunes, River levees and silt
levees, Estuarine river levees, and silted tidal flats.
* Phd: Abdul – Mutalib Hasson Mohammed Al-Marsoumi
E-mail: abdmars@yahoo.com
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