Basalt, is a common extrusive igneous volcanic rock formed from the rapid cooling of basaltic lava exposed at. Basalt describes the formation in a series of lavas flows. This forms dissolved gases come out of solution and form bubbles magma decompresses as it reaches, yet are trapped as erupted hardens grey black brown before can escape. Spongy structure porous crushed and broken stones frozen gibber reg regs geology geological clinkers scoria magmatic cinder cone hill pyroclastic pyroclasts material rocks area solidified shield volcano dome andesitic rhyolite field cinematic background landscape view nature natural UHD 3840X2160.