Qal'eh Hasan Ali
Encyclopedia
Qal'eh Hasan Ali is a maar
-producing volcanic field
located southeast of Kerman Province, Iran
. The field is presumed of Holocene age, though it has produced no historic eruptions. Consisting of 14 maars each of different size, its most major caldera is Great Crater, about 1.2 kilometre (0.745647283979768 mi) in width and 200-300 km in depth.
s of Ali were produced from desert alluvium, granodioritic rocks, and Eocene activity. The group of maars was created separately from the remainder of Iran's stratovolcano
es. All have generated pyroclastic volcanic ash
deposits, though none have actually erupted.
Maar
A maar is a broad, low-relief volcanic crater that is caused by a phreatomagmatic eruption, an explosion caused by groundwater coming into contact with hot lava or magma. A maar characteristically fills with water to form a relatively shallow crater lake. The name comes from the local Moselle...
-producing volcanic field
Volcanic field
A volcanic field is an area of the Earth's crust that is prone to localized volcanic activity. They usually contain 10 to 100 volcanoes, such as cinder cones and are usually in clusters. Lava flows may also occur...
located southeast of Kerman Province, Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
. The field is presumed of Holocene age, though it has produced no historic eruptions. Consisting of 14 maars each of different size, its most major caldera is Great Crater, about 1.2 kilometre (0.745647283979768 mi) in width and 200-300 km in depth.
Geologic history
The maarMaar
A maar is a broad, low-relief volcanic crater that is caused by a phreatomagmatic eruption, an explosion caused by groundwater coming into contact with hot lava or magma. A maar characteristically fills with water to form a relatively shallow crater lake. The name comes from the local Moselle...
s of Ali were produced from desert alluvium, granodioritic rocks, and Eocene activity. The group of maars was created separately from the remainder of Iran's stratovolcano
Stratovolcano
A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...
es. All have generated pyroclastic volcanic ash
Tephra
200px|thumb|right|Tephra horizons in south-central [[Iceland]]. The thick and light coloured layer at center of the photo is [[rhyolitic]] tephra from [[Hekla]]....
deposits, though none have actually erupted.