Mount Tendürek

Tendürek (Turkish: Tendürek Dağı; Armenian: Թոնդրակ, romanized: T’ondrak) is a shield volcano in eastern Turkey. It is situated on the border of Ağrı and Van provinces, near the border with Iran. It is mostly known for being near the believed wreck of Noah's Ark. It is a very large volcano, with its lava flows covering an area of roughly 650 km2 (251 sq mi) across a flat swath of land. It has 2 main features, Greater Tendürek, the main summit crater, and Lesser Tendürek, the smaller crater to the east of the main crater. Its slopes are very gentle and look like a shield, after which the type is named. It is known to have erupted very viscous lava like volcanoes on the island of Hawaii. The volcano is part of a volcanic group surrounding Lake Van which includes the Nemrut Caldera and Mount Ararat. This group of volcanoes formed as a result of continental collision that began roughly 6 million years ago and continued for the next few million years. The first volcanicity in Tendürek started roughly 250,000 years ago and it still is currently active. The latest eruption was in 1855, which is also the latest eruption in Turkey. The eruption was a gas and ash eruption from the summit crater. Since then the volcano has mostly been geothermally active, with some steam and gases being emitted from the summits. However, since 1993, the magma chamber of the volcano has been subsiding, meaning the volcano is entering a dormancy phase.

Tendürek
Tendürek seen from space
Highest point
Elevation3,514 m (11,529 ft)
Prominence1,294 m (4,245 ft)[1]
Coordinates39.37°N 43.87°E / 39.37; 43.87
Geography
Tendürek is located in Turkey
Tendürek
Tendürek
Ağrı and Van provinces, Turkey
Parent rangeArmenian Highlands
Geology
Age of rock250,000 years[2]
Mountain typeShield volcano
Last eruption1855

Geography
Map of volcanoes surrounding Lake Van.

The Tendürek shield volcano is northeast of Lake Van, roughly 25 km (16 mi) from Doğubeyazıt, which is the largest town in the vicinity. It is located in the far eastern portion of the country, approximately 950 km (590 mi) km from Ankara, the capital of Turkey. More than 170,000 people live within the 30 km (19 mi) radius of the volcano, making it a threat to nearby towns and villages if it erupts.[3]

Topography

At the summit of Tendürek are two craters; the larger western peak has a height of 250 m (820 ft) and a diameter of 1 km (1 mi) and is the highest point of the volcano, reaching above 3,500 m (11,483 ft). The eastern peak, also called "Lesser Tendürek" (Küçük Tendürek in Turkish)[4] is about 100 m (328 ft) high with a diameter of 800 m (2,625 ft).[5] The main crater's lava flows completely surrounded the secondary crater (Lesser Tendürek), causing the elevation difference between the craters to be less.[6]

The western crater has a more prominent relief then the eastern crater; it is a funnel shaped crater with a cylindrical trachytic spine in the east rim. The secondary crater is mostly flat, filled with a warm crater lake.[5]

Erupted volcanic material, mostly lava, from these craters covers an area of roughly 650 km2 (251 sq mi).[6] Following the main crater formation, multiple eruptions along the flanks of the volcano with north–south directed fissures occurred, forming trachyte domes and pāhoehoe lava flows, a viscous and very mobile lava type. These eruptions, until 2,500 years ago, expanded the area of lava covering land.[7]

Tectonic setting
Tectonic map of Turkey
Lake Van viewed from satellite; the darker colored terrain in top right is Tendürek

Tendürek is located within the borders of Turkey, a country with one of the most seismic activity and deformation in the world. Therefore, the country is known for its extensive history of large and deadly earthquakes that have caused devastation. The country is located within the Mediterranean Earthquake Belt, a complex deformation zone caused by the collision between the African and the Eurasian Plates.[8]

Tectonics of Turkey are made up of 3 main elements: the Aegean-Cyprus Arc, a convergent plate boundary where the African Plate lithosphere subducts under the Anatolian Plate; the dextral strike-slip North Anatolian Fault where the fault block moves horizontally rightwards against the block across the fault, and the sinistral strike-slip East Anatolian Fault where the fault block moves horizontally leftwards against the block across the fault. The North and East Anatolian Faults are lengthy strike-slip faults where the Anatolian Plate crust slides against the Arabian Plate and the Eurasian Plates to move westward from them. These two faults, in their eastern end, meet and form the Karlıova Triple Junction, a triple strike-slip collision zone.[8]

Regional setting

The volcanism near Lake Van in Eastern Anatolia is thought to have begun in late Miocene as a result of continental collision, as part of a volcanic province that extends 900 km (559 mi) with a width of 350 km (217 mi) towards the northeast at the border of Armenia all the way from Syria.[9] The earliest collision volcanism in the region is thought to be southwest of Erzurum near Solhan, in middle-late Miocene as northward subduction parallel to the Bitlis Thrust Zone (northwest-southeast directed). This subduction, over the next few million years, resulted in the formation of multiple volcanic centers, including Tendürek.[10]

Locally, Tendürek can be found between two long dextral strike-slip faults directed northwest–southeast. These faults accommodate the continental collision.[11]

Petrology

Within the lavas of the volcano, there are predominant basalts and trachyandesites; these are the typical types for Tendürek. The basic lavas (lavas with a lower silica rate) contain phenocrysts of plagioclase, clinopyroxene and uncommon olivine. The intermediate lavas (lavas with a higher silica rate) contain large zoned plagioclase (oligoclase-andesine), glomerocrysts of clinopyroxene and magnetite, both in a plagioclase-rich groundmass.[12]

Eruptive history

Tendürek, since its formation 250 ka ago, has had 5 different phases; phase I (250-200 ka) where the first ever volcanic activity took place with trachybasalts, phase II (200-150 ka) where more volcanic craters and fissures formed with tephrites, phase III (150-100 ka) where the Lesser Tendürek eastern crater began to form and had the activity centralized on it with phonolites and trachyites, phase IV (100-70 ka) where the activity slowed down followed by the formation of the Greater Tendürek western crater with trachyandesites and phase V (50 ka-present) where it continues with phonolitic summit eruptions.[2]

Pre-cone eruptive episodes

Tendürek's first ever volcanic activity began roughly 250,000 years ago with fissure eruptions out of transtensional fault lines.[13][5] These extrusions produced lava composed of trachybasaltic magma like hawaiite and tephritic pyroclastic flows with deposits.[14][15] These pyroclastic materials above a variety of non-volcanic rocks formed the base of the Tendürek volcano. This primary extrusion was followed by a series of explosive tephrite eruptions accommodated by viscous trachybasaltic lava afterwards. Along the pre-cone activity period, multiple domes and clusters of cinder cones formed on north–south trending fissures on the volcano. Erupted mobile tephrite and basalt lava from these cinder cones covered a very large area of 1,000 km2 (386 sq mi) on the Doğubayazıt and Çaldıran plains.[14][16] These lava flows currently remain under younger alluvial deposits.[14] This period lasted roughly 100,000 years.[2]

First main cone formation
Lava flows with Lesser Tendürek in the background

150,000 years ago, right before the cone building phase started, the volcanic activity at the volcano shifted to one central spot where it can be found in the present.[14][2] Later, a new cone (the eastern crater of Lesser Tendürek in the present day) started erupting trachytic and benmoreite lava flows that spreaded equally along the plain the cone was located in.[14][17] Following these, very thin basaltic lavas were erupted, which later spreaded widely and smoothly, carpeting the area. This first episode of cone building activity was concluded by more effusive eruptions, varying from trachytic to basaltic lavas. These lavas formed a radial flank to this central cone, with shallow angles between 20 and 40 degrees. This flank, followed by subsequent eruptions, expanded with more fluid and thin lava flows of the same variety. After this phase, a period of quiescence took place.[14]

In a later period, another new trachytic eruption began, following the eruption of the second main cone. When the erupting lava flows decreased, new ejected lava in the first main cone blocked its crater. This would pause the first main cone's summit eruptions. This caused the pressure forced on the cone to increase. Since the crater of this cone was blocked, a possible internal collapse occurred in the structure of the volcano, causing faults and fractures trending circularly to form in the flanks close to the summit of the complex. These faults cut through the then newly formed volcanic rocks.[14]

Second main cone formation
Greater Tendürek viewed from the ISS, spatter cone in the left of image. Looking northeastward.

The climactic phase of the volcano began when the activity shifted to a new cone (the western crater of Greater Tendürek in the present day) in-between 100,000 and 70,000 years ago.[14][15] This new cone began erupting voluminous and fast moving trachyte and benmoreite lava flows that reached a thickness of 250 m (820 ft).[14][15] These large flows of lava formed the current topographic profile of the volcano. These flows of lava expanded more than 500 km2 (193 sq mi) along the basement of the volcano.[14]

In the summit crater, as a result of the pressure blocking the first main cone (eastern crater), fractures and faults formed in the southern wall of the crater as well. These faults and fractures were filled with magma that formed very thin dikes. Meanwhile, the northwestern wall of the crater is slightly deformed outward of the crater, as a result of forced lava injection into the caldera. The former peak of the volcano along the crater walls is thought to have collapsed as a result of an avalanche caused by an eruption which formed a smaller breached crater. The most recent eruption in 1855 occurred in the summit crater, forming a small, steep-sided cone.[14]

Solid basaltic lava on the flanks of the volcano

Flank eruptions

At the same time as the summit eruptions, some of the magma underground managed to find a different way to get onto the surface, resulting in flank eruptions. These type of eruptions took place far from the main craters, as far as areas without any lava cover. They usually erupted from north–south directed fissures, later forming into a cinder cone. The magma from these eruptions flowed mostly 200 m (656 ft) to 500 m (1,640 ft) wide and were usually 2 m (7 ft) to 4 m (13 ft) tall. These flank extrusions were usually of basaltic-trachytic characteristics. The latest of these extrusions took place roughly 2,500 years ago, in the southeast of the volcano.[18]

Recent dormancy
Map of deformation at Tendürek between May 2018-October 2022.

Tendürek, ever since its last eruption, has continued to be geothermally active. Steam and gas emissions can also be witnessed in both craters and the flanks.[19] However, the summit region of Tendürek has been under subsidence since 1993 as the result of a sill contracting at a depth of 4.5 km (3 mi), indicating upcoming dormancy.[20] The sill in 2013 had dimensions of about 6 km (4 mi) x 7 km (4 mi); it is continuing to decrease in volume as it continues to solidify.[21] The contraction of the sill causes a subsidence of about -11 mm per year at the summit as measured by InSAR.[22] The ring faults around the summits have been reactivated as a result of the subsidence.[23]

Flora and fauna

The Tendürek region is home to multiple endemic plants including Fritillaria michailovskyi, Centaurea demirizii, Campanula coriacea and Calamintha caroli-henricana. Birds that reside in the region include the European roller, European nightjar, ortolan bunting and lesser grey shrike. The steppe eagle is thought to be residing in this area, although there is no exact data.[24]

In culture
The Durupınar site, which has been linked to Noah's Ark.
See also: Searches for Noah's Ark

East of the volcano can be found the Durupınar site, which due to its size and ship-like shape and big aggregate structure is considered by some, without evidence, to be Noah's Ark.[25][26]

The medieval Armenian Tondrakians, a religious movement of the 950s, is named after this area. They were a heretical movement against the Armenian Church in the Byzantine Empire.[27]

See also

References
  1. "Mount Tendurek". PeakVisor. Retrieved July 31, 2023.
  2. Lebedev et al. 2016, p. 133.
  3. "Tendürek Dağı". TurkVolc. Retrieved July 31, 2023.
  4. "Kucuk Tendurek Tepesi". PeakVisor. Retrieved July 31, 2023.
  5. Yılmaz, Güner & Şaroğlu 1998, p. 185.
  6. Lebedev et al. 2016, p. 130.
  7. "Tendürek Dagi". Global Volcanism Program. Smithsonian Institution. Retrieved July 31, 2023.
  8. Bozkurt 2001, p. 3.
  9. Pearce et al. 1990, p. 190.
  10. Pearce et al. 1990, p. 194.
  11. Bathke et al. 2015, p. 158.
  12. Pearce et al. 1990, p. 197.
  13. Lebedev et al. 2016, p. 127.
  14. Yılmaz, Güner & Şaroğlu 1998, p. 186.
  15. Lebedev et al. 2016, p. 139.
  16. Lebedev et al. 2016, p. 138.
  17. Lebedev et al. 2016, p. 140.
  18. Yılmaz, Güner & Şaroğlu 1998, p. 192.
  19. Yılmaz, Güner & Şaroğlu 1998, p. 181.
  20. Gündüz, Yılmaztürk & Orhan 2023, p. 12.
  21. Bathke et al. 2013, p. 4501.
  22. Bathke et al. 2013, p. 4495.
  23. Bathke et al. 2013, p. 4488.
  24. "Tendürek Dağı" (in Turkish). Doğa Derneği. Retrieved July 31, 2023.
  25. Collins, Lorence G. (2011). "A supposed cast of Noah's ark in eastern Turkey" (PDF).
  26. Avci, Murat (2007). ""Noah's Ark": its relationship to the Telçeker earthflow, Mount Ararat, Eastern Turkey". Bulletin of Engineering Geology and the Environment. 66 (3): 377–380. doi:10.1007/s10064-007-0084-3. S2CID 129721550.
  27. Yianni Cartledge & Brenton Griffin, 'Sunk in the…Gulf of Perdition': The 'Heretical' Paulician and Tondrakian Movements in the Periphery of the Medieval Byzantine Empire', Cerae, 9, 2022, 235-271.

Sources
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