volcanic rock forms when lava cools after a volcanic eruption.
what type of rocks form when lava cools after a volcanic eruption?
volcanic rock
flow bands are present in massive, uniform felsic lava flow units. when the viscous lava flow encounters a surface, friction drags the mobile lava and forms internal banding.





























structureless hyaloclastite is commonly found in archean felsic volcanic rocks. in submarine environments, water quenches and cools lava rapidly during volcanic eruption. the flow is fragmented and form glassy volcanic breccia.





























section::::characteristics.:geochemistry.
archean felsic volcanic rocks
obsidian is the rock formed as a result of quickly cooled lava, which is the parent material. extrusive formation of obsidian may occur when felsic lava cools rapidly at the edges of a felsic lava flow or volcanic dome or when lava cools during sudden contact with water or air. intrusive formation of obsidian may occur when felsic lava cools along the edges of a dike.





























tektites were once thought by many to be obsidian produced by lunar volcanic eruptions, though few scientists now adhere to this hypothesis.
obsidian