Volcanic pipe Volcanic pipe Volcanic pipes are subterranean geological structures formed by the violent, supersonic eruption of deep-origin volcanoes. They are considered to be a type of "diatreme". Volcanic pipes are composed of a deep, narrow cone of solidified magma (described as "carrot-shaped"), and are usually largely composed of one of two characteristic rock types — kimberlite or lamproite. These rocks reflect the composition of the volcanoes' deep magma sources, where the Earth is rich in magnesium. Volcanic pipes are relatively rare. They are well known as the primary source of diamonds, and are mined for this purpose. Volcanic pipes form as
ARIA Award for Best Rock Album ARIA Award for Best Rock Album The ARIA Music Award for Best Rock Album, is an award presented at the annual ARIA Music Awards, which recognises "the many achievements of Aussie artists across all music genres", since 1987. It is handed out by the Australian Recording Industry Association (ARIA), an organisation whose aim is "to advance the interests of the Australian record industry." To be eligible, the recording must be an album in the contemporary rock, modern rock and active rock formats, and cannot be entered in other genre categories. The accolade is voted for by the ARIA Judging Academy,