Taftan () (, Taftân, Balochi & also in Persian for "blistering, smoldering, fuming") is an active stratovolcano in south-eastern Iran in the Sistan and Baluchestan province. With variable heights reported, all around 4,000 metres (13,000 ft) above sea level, it is the highest mountain in south-eastern Iran. The nearest city is Khash.
Taftan has two main summits, Narkuh and Madehkuh, and various heights have been reported for both summits. The northwestern Narkuh has two craters and is the older of the two summits. The southeastern Madehkuh summit is surrounded by fresh-looking lava flows and has at least three craters. The principal rock at Taftan is andesite.
Reports of historical volcanic activity are unclear and the youngest radiometric dates are 6,950 ± 20 years before present. Currently, the volcano features vigorous fumarolic activity that is visible from a great distance and involves numerous vents on Materkuh. Taftan appears to be part of a geothermal area, and a number of hot springs can be found around the volcano.
Taftan is part of a volcanic arc in Iran, together with Bazman, also in Iran, and Koh-i-Sultan in Pakistan. This volcanic arc has formed on Cretaceous-Eocene sedimentary layers and has resulted from the subduction of the oceanic Arabian plate beneath Iran at the Makran trench.
Geography and geology
Taftan is in Iran's Sistan and Balochistan province. Closest cities are Khash south and Zahedan north north-west. In 1844, Abdul-Nabi reported of the existence of the mountain, as well as its volcanic activity. In 1971, it was reported that some Beluch tribes camp on Taftan's slopes outside of winter.
Regional setting
Volcanic activity has occurred in parts of Iran since the Cretaceous period. During the Eocene and Oligocene epochs, volcanic activity reached its maximum, with thick pyroclastic layers being deposited in central Iran and the Alborz mountains. The area around Taftan volcano belongs to a tectonic zone which is variously referred to as the Sistan suture or the Zabul-Baloch zone. There, after a previous episode of rifting and subsequent formation of an ocean, the Neh and Lut tectonic blocks collided during the Eocene epoch after a subduction episode that commenced in the Maastrichtian age.
Volcanic activity at Taftan itself appears to relate to the subduction of the Arabian plate beneath the Central Iran plate, occurring at a pace of or at the Makran trench. This subduction is also responsible for volcanism at Bazman in Iran and Koh-i-Sultan in Pakistan; this chain is known as the Baluchistan volcanic arc. The volcanism appears to not align with pre-existent structural trends in the basement. This subduction has also created an accretionary wedge that forms the Makran region.
The convergence of the two blocks continued even after their collision, generating strike-slip faults. The Saravan fault east of Taftan is one such fault; the 2013 Saravan earthquake occurred on this fault. From some of these faults it has been inferred that the mass load from the Taftan edifice has measurable effects on tectonic stress within the region.
Local setting
Taftan is the highest mountain in southeast Iran. The topography is overall steep. Deep valleys with U and V shapes have developed on Taftan, and the volcano has a strongly eroded appearance. One of these valleys, Tamindan, may be the Damindan valley in the Avesta religious texts. One series of ignimbrites surrounding Taftan which reaches thicknesses of and reaches distances of from the edifice may be 2 million years old.
The basement of Taftan is formed by various sedimentary rocks, along with some mafic volcanic rocks and metamorphic rocks. At Taftan, the Nehbandan-Khash flysch borders the Makran zone. The oldest rocks are limestones from the Cretaceous period. The crust beneath Taftan is approximately thick. The main edifice is constructed on top of the Eocene flysch, although some Cretaceous sediments are also part of the basement. Much of these rocks is coloured pink by haematite. The 19 mya old Mirabad granite pluton may be associated with Taftan; it could be the remnant of a Miocene volcano. Volcanic rocks of Quaternary age are widespread in the area.