Alborz Mountain Range

Alborz (Persian: البرز‎‎), 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 northeast and merges into the Aladagh Mountains in the northern parts of Khorasan. This mountain range is divided into Western, Central, and Eastern Alborz Mountains. The Western Alborz Range (usually called the Talish Mountains) runs south-southeastward almost along the western coast of the Caspian Sea. The Central Alborz (the Alborz Mountains in the strictest sense) runs from west to east along the entire southern coast of the Caspian Sea, while the Eastern Alborz runs in a northeasterly direction towards the northern parts of the Khorasan region southeast of the Caspian Sea. Mount Damavand, the highest mountain in Iran, is located in the Central Alborz Mountains.

The Alborz mountain range forms a barrier between the south Caspian and the Iranian plateau. It is only 60–۱۳۰ km wide and consists of sedimentary series dating from Upper Devonian to Oligocene, prevalently Jurassic limestone over a granite core. Continental conditions regarding sedimentation are reflected by thick Devonian sandstones and by Jurassic shales containing coal seams. Marine conditions are reflected by Carboniferous and Permian strata that are composed mainly of limestones. In the Eastern Alborz Range, the far eastern section is formed by Mesozoic (chiefly Triassic and Jurassic) rocks, while the western part of the Eastern Alborz Range is made primarily of Paleozoic rocks. Precambrian rocks can be found chiefly south of the city of Gorgan situated in the southeast of the Caspian Sea and in much smaller portions in the central and western parts of the Central Alborz Range. The central part of the Central Alborz Range is formed mainly of the Triassic and Jurassic rocks, while the northwestern section of the range is made mainly of the Jurassic rocks. Very thick beds of the Tertiary (mostly of the Eocene) green volcanic tuffs and lavas are found mainly in the southwestern and south-central parts of the range. The far northwestern part of the Alborz that constitutes what is called the Western Alborz Range or the Talish Mountains is made mainly of the Upper Cretaceous volcano-sedimentary deposits with a strip of Paleozoic rocks and a band of Triassic and Jurassic rocks in the southern parts, both in a northwest-southeast direction. As the Tethys Sea was closed and the Arabian Plate collided with the Iranian Plate and was pushed against it, and with the clockwise movement of the Eurasian Plate towards the Iranian Plate and their final collision, the Iranian Plate was pressed from both sides. The collisions finally caused the folding of the Upper Paleozoic, Mesozoic, and Paleogene rocks, and the Cenozoic (chiefly the Eocene) volcanism to form the Alborz Mountains mainly in the Miocene. The Alpine orogeny began, therefore, with Eocene volcanism in southwestern and south-central parts of the Alborz and continued with the uplift and folding of the older sedimentary rocks in the northwestern, central and eastern parts of the range during the orogenic phases of importance that date from the Miocene and the Pliocene epochs.

In the photo above, the mountain overlooking the plain of Tehran (capital of Iran) can be seen. The mountains have formed the southern boundary of Alborz Mountain. The highest peak in this section, is Tochal (3962 meters). In the far right of the photo, Mount Damavand (5671 m), the highest peak in Iran is seen. This peak is the highest volcano in Asia.

In the southern part of Alborz in northern Tehran, pyroclastic rocks, shale and volcanic rocks are abundant. This stones are called green series or “Karaj formation”. More than 3,000 meters of sediments were deposited at the Eocene in this part of the Alborz, and the Karaj formation is created.

The Photo was taken by Amir Hossein Azizian, over “Milad Tower” in Tehran.

Keywords: Alborz Mountain , Elborz , Elburz , Eocene , Iran Geology , Iran Geotourism , Karaj formation , Milad tower , Mountain range , Orogeny , Pyroclastic ,Tehran , Tochal peak , Volcanism , zamingasht

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