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 complex is built on partly sedimentary rock and partly volcanogenic Late Cretaceous and Eocene series with Paleogene intrusions.