This dark gray igneous rock is glassy and elsewhere contains small vesicles and flow bands.

this dark gray igneous rock is glassy and elsewhere contains small vesicles and flow bands. what kind of eruption probably formed this rock?eruption of a low-viscosity, basaltic lava flow eruption of high-viscosity lava in a dome dome collapse that forms volcanic breccia eruption of a pyroclastic flow that forms a thick and hot deposit slow settling of ash from a tall eruption column forming a nonwelded tuff