Porak or Axarbaxar ("gutted belly" in Azerbaijani
) is a
stratovolcano
A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and per ...
located in the
Vardenis volcanic ridge. It lies about southeast of
Lake Sevan and the
volcanic field
A volcanic field is an area of Earth's crust that is prone to localized volcanic activity. The type and number of volcanoes required to be called a "field" is not well-defined. Volcanic fields usually consist of clusters of up to 100 volcanoes ...
spans the border between
Armenia
Armenia (), , group=pron officially the Republic of Armenia,, is a landlocked country in the Armenian Highlands of Western Asia.The UNbr>classification of world regions places Armenia in Western Asia; the CIA World Factbook , , and ''Ox ...
and
Azerbaijan
Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of th ...
with
lava flow
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or und ...
s running into both countries. Ten
satellite cone
A parasitic cone (also adventive cone or satellite cone) is the cone-shaped accumulation of volcanic material not part of the central vent of a volcano. It forms from eruptions from fractures on the flank of the volcano. These fractures occur ...
s and fissure vents lie on the flanks of the volcano.
The Porak volcano itself and the third stage has been dated 15 ± 15
ka by
K-Ar dating.
Two long lava flows, one of which 21 km long, stretch from the field north and northeastwards. There are thermal springs in the area, and the Middle Pleistocene Khonarassar fault area lies to the north of the Porak centre.
The Karkar volcanoes are situated in the same region.
The complex is built on partly
sedimentary rock
Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...
and partly
volcano
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plates are ...
genic
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...
and
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' ...
series with
Paleogene
The Paleogene ( ; British English, also spelled Palaeogene or Palæogene; informally Lower Tertiary or Early Tertiary) is a geologic period, geologic period and system that spans 43 million years from the end of the Cretaceous Period million yea ...
intrusions.
Description
There are four stages of
trachyandesitic lava flows, the oldest composing the Porak volcano itself and the younger three derived from cones and fissures.
Two lava flows overlay Sevan Lake deposits with thin soil cover form an early Holocene stage. The second stage forms lava flows entering
Lake Alaghel and is devoid of soil cover.
Several archaeological sites (one of these dated by radiocarbon analysis on charcoal to be no younger than 3080±40 BP-3200±40
BP) are constructed on the two oldest Holocene stages but not on the most recent stage. Third-stage lava flows run at the edge of one of these sites which was constructed on lavas from the previous two stages, suggesting that the site was affected by historical volcanic activity. There is also evidence of strong earthquake activity 6640±90 BP and between 782 and 773 BC.
The volcano may have potential for
geothermal power
Geothermal power is electrical power generated from geothermal energy. Technologies in use include dry steam power stations, flash steam power stations and binary cycle power stations. Geothermal electricity generation is currently used in 2 ...
generation but is also a potential threat to several villages in the area.
Khorkhor inscription
The
Khorkhor inscription, in which
Argishti I of
Urartu
Urartu (; Assyrian: ',Eberhard Schrader, ''The Cuneiform inscriptions and the Old Testament'' (1885), p. 65. Babylonian: ''Urashtu'', he, אֲרָרָט ''Ararat'') is a geographical region and Iron Age kingdom also known as the Kingdom of Va ...
records the conquest of the city of
Behoura, records that during the siege the town was destroyed by an earthquake and eruption of "Mount Bamni". Historians consider it likely that Porak volcano is Mount Bamni and that Behoura was one of the archeological sites in the area.
The location of Behoura is controversial, however. The identification of another inscription by Argishti's successor,
Sarduri II, gives evidence of another eruption of Porak.
Older evidence of volcanic activity, including
lacustrine deposits, indicate temporary disappearance of forests in the area before 6,270BP, likely due to forest fires induced by volcanic activity.
Petroglyph
A petroglyph is an image created by removing part of a rock surface by incising, picking, carving, or abrading, as a form of rock art. Outside North America, scholars often use terms such as "carving", "engraving", or other descriptions ...
s dated about 5,000BP also portray volcanic activity,
together with even older portrayals of volcanic eruptions in
Chauvet Cave (
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...
) and in
Çatalhöyük
Çatalhöyük (; also ''Çatal Höyük'' and ''Çatal Hüyük''; from Turkish ''çatal'' "fork" + ''höyük'' "tumulus") is a tell of a very large Neolithic and Chalcolithic proto-city settlement in southern Anatolia, which existed from appr ...
(
Turkey
Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a list of transcontinental countries, transcontinental country located mainly on the Anatolia, Anatolian Peninsula in Western Asia, with ...
) they are among the oldest records of volcanic activity in the world (these other portrayals related to the Bas-Vivarais volcanic field in the
Massif Central
The (; oc, Massís Central, ; literally ''"Central Massif"'') is a highland region in south-central France, consisting of mountains and plateaus. It covers about 15% of mainland France.
Subject to volcanism that has subsided in the last 10,00 ...
and to
Hasan Dagi, respectively).
It is not entirely clear which eruption is depicted by the Porak petroglyphs.
References
{{Mountains in Azerbaijan
Subduction volcanoes
Volcanoes of Armenia
Mountains of Armenia
Mountains of Azerbaijan
Volcanoes of Azerbaijan
Pleistocene stratovolcanoes
Polygenetic volcanoes
Armenia–Azerbaijan border
International mountains of Europe
International mountains of Asia
Stratovolcanoes of Asia