The Tehran Plain is a landscape formation in Iran delimited by the adjacent

Alborz Mountain range The Alborz ( fa, البرز) range, also spelled as Alburz, Elburz or Elborz, is a mountain range in northern Iran that stretches from the border of Azerbaijan along the western and entire southern coast of the Caspian Sea and finally runs nort ...

. It is a site of prehistoric archaeological and geoscientific interest. Numerous faults and deformed

quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ...

units in the Tehran plain prove it is a region of ancient tectonic activity.

Geology

The Tehran Plain is a landscape formation in Iran. It consists of

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

and

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ...

sediments.Angela Landgraf, Lucilla Benedetti, Regis Braucher, Didier Bourles et al
Pleistocene deformation and landscape evolution in the Tehran plain: results from tectonic geomorphology and TCN-dating.
Geophysical Research Abstracts, Vol. 12, EGU2010-11196, 2010 EGU General Assembly, 2010 The North Tehran Fault thrust up

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

rocks of the

. Geomorphologically three different zones can be described: In the western part, the plain has been deformed by

thrusting Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that sys ...

, as can be seen by a segmented and internally deformed

anticline In structural geology, an anticline is a type of fold that is an arch-like shape and has its oldest beds at its core, whereas a syncline is the inverse of an anticline. A typical anticline is convex up in which the hinge or crest is the ...

and old and diverted channels on both sides. This process has been dated at possibly after 25,000 years. In the central part of the plain, which lies below the

megacity A megacity is a very large city, typically with a population of more than 10 million people. Precise definitions vary: the United Nations Department of Economic and Social Affairs in its 2018 "World Urbanization Prospects" report counted urban ...

Tehran Tehran (; fa, تهران ) is the largest city in Tehran Province and the capital of Iran. With a population of around 9 million in the city and around 16 million in the larger metropolitan area of Greater Tehran, Tehran is the most popul ...

, thrusting and left-lateral

strike-slip In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

faulting has caused several uplifted

fluvial terrace Fluvial terraces are elongated terraces that flank the sides of floodplains and fluvial valleys all over the world. They consist of a relatively level strip of land, called a "tread", separated from either an adjacent floodplain, other fluvial te ...

s, reminiscent of a transpressional structure of uncertain age, possibly ~195,000 years, i.e.

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

. In the Eastern part, ramp-structures are ~195,000y-old, of middle Pleistocene

Archaeology

A channel for artificial water management on the Tehran Plain dating from the

Late Neolithic In the archaeology of Southwest Asia, the Late Neolithic, also known as the Ceramic Neolithic or Pottery Neolithic, is the final part of the Neolithic period, following on from the Pre-Pottery Neolithic and preceding the Chalcolithic. It is some ...

was described in 2009, suggesting that farmers at Tepe Pardis in Iran irrigated crops in the 6th millennium. This corresponds to findings from

Choga Mami Choga Mami is a Samarran settlement site in Diyala province in Eastern Iraq in the Mandali region. It shows the first canal irrigation in operation at about 6000 BCE. The site, about 70 miles northeast of Baghdad, has been dated to the late 6th m ...

in Iraq.

Stone tool A stone tool is, in the most general sense, any tool made either partially or entirely out of stone. Although stone tool-dependent societies and cultures still exist today, most stone tools are associated with prehistoric (particularly Stone Ag ...

finds on the Tehran Plain from the late Neolithic through to Early

Chalcolithic The Copper Age, also called the Chalcolithic (; from grc-gre, χαλκός ''khalkós'', "copper" and ''líthos'', "stone") or (A)eneolithic (from Latin '' aeneus'' "of copper"), is an archaeological period characterized by regular ...

show that stone blade production was organised around craft specialists and also part-time blade producers within the household economy and the craft collapsed with increasing use of bronze. Study of a "landlord village" in Qasemabad, Pishva (also spelled Kazemabad) on the plain has allowed understanding the social and economic organisation of much of Iran's rural population as it was rooted in the early Islamic period until the 1963 White Revolution. Landlord villages were enclosed by a mud brick wall and four bastions. The landlord-owner had a large house while his tenant farmers, who tended irrigated land outside the village had smaller houses. The structure enforced inequality, poverty and the power of the landlord.

Water

Groundwater sampling in southern parts of Tehran plain in 2012 found more than half of the samples unsuitable for drinking and agricultural use because of high levels of salinity.

References

{{coord missing, Tehran Province Landforms of Tehran Province Iranian Plateau Archaeological sites in Iran