Zagros Mountains

The Zagros Mountains are a mountain range in Iran, northern Iraq, and southeastern Turkey. The mountain range has a total length of. The Zagros range begins in northwestern Iran and roughly follows Iran's western border while covering much of southeastern Turkey and northeastern Iraq. From this border region, the range continues southeast to the waters of the Persian Gulf. It spans the southern parts of the Armenian highlands, and the whole length of the western and southwestern Iranian plateau, ending at the Strait of Hormuz. The highest point is Mount Dena, at.

Geology

The Zagros fold and thrust belt was mainly formed by the collision of two tectonic plates, the Eurasian Plate and the Arabian Plate. This collision mainly happened during the Miocene and folded the entirety of the rocks that had been deposited from the Paleozoic to the Cenozoic in the passive continental margin on the Arabian Plate. However, the obduction of Neotethys oceanic crust during the Cretaceous, and the continental arc collision in the Eocene both had major effects on uplifts in the northeastern parts of the belt.
The process of collision continues to the present, and as the Arabian Plate is being pushed against the Eurasian Plate, the Zagros Mountains and the Iranian plateau are getting higher and higher. Recent GPS measurements in Iran have shown that this collision is still active and the resulting deformation is distributed non-uniformly in the country, mainly taken up in the major mountain belts like Alborz and Zagros. A relatively dense GPS network which covered the Iranian Zagros also proves a high rate of deformation within the Zagros. The GPS results show that the current rate of shortening in the southeast Zagros is ~, dropping to ~ in the northwest Zagros. The north–south Kazerun strike-slip fault divides the Zagros into two distinct zones of deformation. The GPS results also show different shortening directions along the belt, normal shortening in the southeast, and oblique shortening in the northwest Zagros. The Zagros mountains were created around the time of the second ice age, which caused the tectonic collision, leading to its uniqueness.
The sedimentary cover in the SE Zagros is deforming above a layer of rock salt, whereas in the NW Zagros the salt layer is missing or is very thin. This different basal friction is partly responsible for the different topographies on either side of the Kazerun fault. Higher topography and narrower zone of deformation in the NW Zagros is observed whereas in the SE, deformation was spread more and a wider zone of deformation with lower topography was formed. Stresses induced in the Earth's crust by the collision caused extensive folding of the preexisting layered sedimentary rocks. Subsequent erosion removed softer rocks, such as mudstone and siltstone while leaving harder rocks, such as limestone and dolomite. This differential erosion formed the linear ridges of the Zagros Mountains.
The depositional environment and tectonic history of the rocks were conducive to the formation and trapping of petroleum, and the Zagros region is an important area for oil production. Salt domes and salt glaciers are a common feature of the Zagros Mountains. Salt domes are an important target for petroleum exploration, as the impermeable salt frequently traps petroleum beneath other rock layers. There is also much water-soluble gypsum in the region.

Type and age of rock

The mountains are completely of sedimentary origin and are made primarily of limestone. In the Elevated Zagros or the Higher Zagros, the Paleozoic rocks can be found mainly in the upper and higher sections of the peaks of the Zagros Mountains, along the Zagros main fault. On both sides of this fault, there are Mesozoic rocks, a combination of Triassic and Jurassic rocks that are surrounded by Cretaceous rocks on both sides. The Folded Zagros is formed mainly of Tertiary rocks, with the Paleogene rocks south of the Cretaceous rocks and then the Neogene rocks south of the Paleogene rocks. The mountains are divided into many parallel sub-ranges, and orogenically have the same age as the Alps.
Iran's main oilfields lie in the western central foothills of the Zagros mountain range. The southern ranges of the Fars province have somewhat lower summits, reaching. They contain some limestone rocks showing abundant marine fossils.

Highest peaks

The peaks that are at least 3800 meters high and have a topographic prominence of at least 300 meters:

	Name	Sub-range	Height	Prominence
1	Qash-Mastan	Dena	4409	2604
2	Kale Qodveis	Dena	4341	424
3	Pazane Pir	Dena	4250	1080
4	Kuh-e Dama	Dena	4216	504
5	Kolonchin	Zard-Kuh	4221	2095
6	Chegaleh	Zard-Kuh	4134	594
7	Haft Tanan	Zard-Kuh	4104	653
8	San-Borān	Oshtorankuh	4150	1928
9	Qalikuh		4078	1420
10	Shahankuh		4038	1427
11	Qanbarkosh		3982	316
12	Haft Cheshmeh		3975	1545
13	Cheshmeh Kuhrang		3969	360
14	Karpush		3961	915
15	Bel		3943	1563
16	Khurbeh		3902	915
17	Darab Shah		3900	1495
18	Piaro Kamandan		3891	370
19	Hezar Darreh		3890	1628
20	Kuh-e Hashtad		3869	1248
21	Chahardah Pahlu		3845	949
22	Dome Qalikuh		3839	602
23	Kule Jonou		3823	422
24	Halgurd Mountain		3607	1575

History

The Zagros Mountains have significant ancient history. They were occupied by early humans since the Lower Paleolithic Period. The earliest human fossils discovered in Zagros belong to Neanderthals and come from Shanidar Cave, Bisitun Cave, and Wezmeh Cave. The remains of ten Neanderthals, dating from around 65,000–35,000 years ago, have been found in the Shanidar Cave. The cave also contains two later "proto-Neolithic" cemeteries, one of which dates back about 10,600 years and contains 35 individuals. Iran's Middle Paleolithic sites are mostly located in the Zagros. Mousterian stone tools can be found at these cave sites. Evidence from later Upper Paleolithic and Epipaleolithic occupations come from Yafteh Cave, Kaldar Cave near Khoramabad, and Warwasi, Malaverd near Kermanshah, Kenacheh Cave in Kurdistan, Boof Cave in Fars and a number of other caves and rock shelters. The Upper Paleolithic is characterized by Baradostian and Zarzian stone tools. Compared to the Mousterian the Baradostian shows an increase in the number of tool types as well as a greater emphasis on tool making techniques.
Signs of early agriculture date back as far as 9000 BC in the foothills of the mountains. Some settlements later grew into cities, eventually named Anshan and Susa; Jarmo is one archaeological site in this area. Some of the earliest evidence of wine production has been discovered in the mountains; both the settlements of Hajji Firuz Tepe and Godin Tepe have given evidence of wine storage dating between 3500 and 5400 BC.
A human metatarsal bone fragment from Wezmeh Cave has been analyzed and dated to the Neolithic period. The DNA from this bone fragment shows that it is from a distinct genetic group, which was not known to scientists before. He belongs to the Y-DNA haplogroup G2b, specifically its branch G-Y37100, and mitochondrial haplogroup J1d6. He had brown eyes, relatively dark skin, and black hair, although Neolithic pre Indo-European Iranians carried reduced pigmentation-associated alleles in several genes and derived alleles at 7 of the 12 loci, showing the strongest signatures of selection in ancient Eurasians. He did not contribute to the genetic makeup of early European farmers or modern Europeans. Instead, he was the most genetically similar to modern Iranian Zoroastrians, followed by Fars, Balochi, Brahui, Kalash and Georgians. Gallego-Llorente et al. believes that the Zagros Mountain was a plausible source of Eurasian ancestry in Central and South Asia, along with Kotias, which was inhabited by Caucasus Hunter-Gatherers. He cites archaeological evidence of eastward Neolithic expansions from the Near East.
During early ancient times, the Zagros was the home of various Pre Indo-European peoples such as the Hurrians, Guti, Kassites, Elamites, Turukku and Lullubi, who periodically invaded the Sumerian, Akkadian and Assyrian cities of Mesopotamia. The mountains create a geographic barrier between the Mesopotamian Plain, which is in modern Iraq, and the Iranian plateau. A small archive of clay tablets detailing the complex interactions of these groups in the early second millennium BC has been found at Tell Shemshara along the Little Zab. Tell Bazmusian, near Shemshara, was occupied between 5000 BCE and 800 CE, although not continuously.

Population

The Zagros mountains have been inhabited by different groups of pastoralists and farmers for thousands of years. Current Pastoralist groups such as Lurs, Bakhtiari Lurs, Kurds or Qashqais move from their herds from the east slopes in summer to the west slopes in winter. Some major cities are located on the foothills of the Zagros mountains, including Sulaymaniyah, Kermanshah, Khorramabad, and Shiraz. According to Oberlander, the "traditional ethno-geographic divisions of the Zagros Highland have real significance, for the lands of the various tribal groups are different. Each has a character of its own. Accordingly, Kurdistan, Luristan, the Bakhtiari, Kuhgalu, and Fars are distinctive geographic entities in a physical sense as well as an ethnic sense."