Igneous rock the partial melting of rocks within the mantle and crust. Extrusive igneous rocks cool and solidify quicker than intrusive igneous rocks. They are formed by the cooling of molten magma on the earth's surface. The magma, which is brought to the surface through fissures or volcanic eruptions, solidifies at a faster rate. Hence such rocks are smooth, crystalline and fine-grained. Basalt is a common extrusive igneous rock and forms lava flows, lava sheets and lava plateaus. Some kinds of basalt solidify to form long polygonal columns. The Giant's Causeway in Antrim, Northern Ireland is an example. The molten rock, with
Booker T. & the M.G.'s Steve Potts. The band was inducted into the Rock and Roll Hall of Fame in 1992, the Musicians Hall of Fame and Museum in Nashville, Tennessee, in 2008, and the Memphis Music Hall of Fame in 2012. Having two white members (Cropper and Dunn), Booker T. & the M.G.'s was one of the first racially integrated rock groups, at a time when soul music and the Memphis music scene in particular were generally considered the preserve of black culture. Booker T. & the M.G.'s formed as the house band of Stax Records, providing backing music for numerous singers, including Wilson