11. The first volcanic activity beginning 2 million years ago formed voluminous lava flows from fissure vents . 12. "' Lj�sufj�ll "'is a fissure vent system and central volcano on the Sn�fellsnes Peninsula in Iceland. 13. Cord�n Caulle evolved during this time from being a shield volcano to a graben with fissure vents . 14. "' Vatnafj�ll "'is a long, wide basaltic fissure vent system that is located southeast of Hekla, Iceland. 15. The " M�vatn fires " occurred between 1724 1729, when many of the fissure vents opened up. 16. Lava from the fissure vent tended to flow downhill toward the southeast, covering part of the fissure. 17. A fissure vent in the "'Fimmv�r�uh�ls "'region of southern Iceland, caused by the Norse god of thunder. 18. Max then comes across a fissure vent . 19. They discovered a fissure vent near the summit caldera a bit to the west of " Gu�nasteinn ". 20. Situated northwest of Armenian capital Yerevan, Aragats is a large volcano with numerous fissure vents and adventive cones.
