Qal'eh Hasan Ali volcano is a group of 14 maars about 5,000-50,000 years old in SE Iran. The maars range from 150 to 1200 m in diameter. The largest of the maars Great Crater, 1.2 km wide and 200-300 m deep.
The maars of Qal'eh Hasan Ali were erupted through layers of desert alluvium, granodioritic rocks, and older Eocene volcanics. They are located in an area several hundred km away from the closest Quaternary volcanoes. The maars produced tephritic pyroclastic deposits.
