Gegham mountains (or Gegham Ridge ; Armenian : Գեղամա լեռնաշղթա , romanized : Geġama lernasheghta ) are a range of mountains in Armenia . The range is a tableland-type watershed basin of Sevan Lake from east, inflows of rivers Araks and Hrazdan from north and west, Azat and Vedi rivers from south-west and Arpachai river from south. The average elevation of the Gegham mountain range is near 2500m. The range is of volcanic origin including many extinct volcanoes . The range is 70 km length and 48 km width, and stretch between Lake Sevan and the Ararat plain . The highest peak of the Gegham mountains is the Azhdahak , at 3597m. They are formed by a volcanic field , containing Pleistocene -to- Holocene lava domes and cinder cones . The highland reaches a height of 1800–2000m up to 3000m in the dividing ridge.
11-833: Volcanism in Armenia and in the Gegham mountains is related to mantle processes accompanying, but not necessarily related to the collision of the Arabian Plate with the Eurasian Plate . Unlike in other parts of the Caucasus region, the Gegham mountains have generated primarily small scale volcanoes. The Kaputan Formation (including Mt. Atis and Gtsain Ridge) from the Late Miocene has been dated at 5.7–4.6 Ma by K-Ar and
22-642: Is the oldest sequence in the region. Late Pliocene activity involved various basaltic lavas (including Lchain Volcano) and subsequently, during the Quaternary , rhyolite and obsidian from the Kotayk centre (Gutansar and Atis 700 ka, then associated fissure volcanoes 550–480 ka). The volcanic activity peaked round 200 ka, when most of the Gegham centres formed from trachyandesitic lavas. Aknotsasar and Sevkatar were active less than 100ka ago. The highest point
33-478: Is the volcano Azhdahak , elevation - 3597.3m above sea level, in the western part of the range. There is a lake in the crater of the volcano Azhdahak that is formed from melting snow. The volcanoes Spitaksar (3560 m) and Geghasar (3446 m), the former erupted 120ka ago and the latter 80-40ka, are sources of obsidian in Armenia. Bird fauna of Gegham mountains includes about 250 species, 70% of all Armenia's avifauna. The southeastern slopes of Gegham mountains contain
44-883: The Anti-Lebanon Mountains ( Lebanon ), parts of Awdal ( Somalia / Somaliland ), the Khuzestan Province ( Iran ), the Southeastern Anatolia Region ( Turkey ), and the Southern Denkalya Subregion ( Eritrea ). Harrat Rahat Ḥarrat Rahāṭ ( Arabic : حَرَّة رَهَاط ) is a volcanic lava field in the Hejazi region of Saudi Arabia . In 1256 CE, a 0.5 km (0.12 cu mi) lava flow erupted from six aligned scoria cones, and traveled 23 km (14 miles) to within 4 km (2.5 miles) of
55-975: The Arabian Peninsula ; it extends westward to the Sinai Peninsula and the Red Sea and northward to the Levant . The plate borders are: The Arabian plate was part of the African plate during most of the Phanerozoic Eon ( Paleozoic – Cenozoic ), until the Oligocene Epoch of the Cenozoic Era. The Red Sea rifting began in the Eocene , and the separation of Africa and Arabia occurred approximately 25 million years ago in
66-778: The Eurasian plate . This collision is resulting in a mingling of plate pieces and mountain ranges extending in the west from the Pyrenees , crossing Southern Europe to Iranian plateau , forming the Alborz and the Zagros Mountains , to the Himalayas and ranges of Southeast Asia . The Arabian plate is a designation of the region, and it is also sometimes referred to as the Arab plate . The Arabian plate consists mostly of
77-514: The Islamic holy city of Medina ; this was its last eruption . There were earlier eruptions, such as in 641 CE, which made finger-like flows to the east of the 1256 CE flow. It is the biggest lava field in Saudi Arabia. Nearby is Al Wahbah crater . There has been recent increase in seismic activity since 2009. Other notes: This article about the geography of Saudi Arabia is
88-537: The Khosrov Forest , planted in the 4th century by Khosrov I and converted into a state park in 1958. The Gegham mountains are one of the primary presences of the vavilovia ( Lathyrus formosus ) around Mount Sevsar. Another species Poa greuteri is endemic in the area. A great number of petroglyphs - rock-carvings has been found in the area of Gegham Mountains. Most images depict men in scenes of hunting and fighting, and astronomical bodies and phenomena:
99-498: The Arabian plate and Eurasia is pushing up the Zagros Mountains of Iran. Because the Arabian plate and Eurasian plate collide, some cities such as those in southeastern Turkey (which is on the Arabian plate) may undergo earthquakes, tsunamis, and volcanoes. Countries within the plate include Bahrain , Djibouti , Iraq , Jordan , Kuwait , Oman , Qatar , Saudi Arabia , Syria , United Arab Emirates and Yemen . Regions include
110-656: The Oligocene, and since then the Arabian plate has been moving toward the Eurasian plate. The opening of the Red Sea rift led to volcanic activity. There are volcanic fields called the Older Harrats, such as Harrat Khaybar and Harrat Rahat , cover parts of the western Arabian plate. Some activity still continues especially around Medina , and there are regular eruptions within the Red Sea. The collision between
121-624: The Sun, the Moon, constellations, the stellar sky, lightning, etc. Carvings of birds have attracted some archeological interest. Arabian Plate The Arabian plate is a minor tectonic plate in the Northern and Eastern Hemispheres . It is one of the three continental plates (along with the African and Indian plates) that have been moving northward in geological history and colliding with
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