GEOSCIENCE

           The Qal'eh Hasan Ali volcanic field in SE Iran contains 14 maars of late Quaternary age. The maars were erupted through desert alluvium, granodioritic rocks, and Eocene volcanics in an area several hundred km away from the closest Quaternary volcanoes. The maars produced tephritic pyroclastic deposits. The diameters of the maars range from 150 to 1200 m; the largest, known as Great Crater, is 1.2 km wide and 200-300 m deep. The ages of the maars have been roughly estimated by degree of erosion as 5000-50,000 years (Milton, 1976-77).