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 which consists of 1000 members from different areas of the music industry, and is given to a solo artist or group who is either from Australia or an Australian resident. The award for Best Rock Album has been won by Powderfinger the most time, with three wins, for: "Internationalist" (1999), "Odyssey Number Five" (2000) and "Vulture Street". In the following table, the winner is highlighted in a separate colour, and in boldface; the nominees are those that are not highlighted or in boldface. ARIA Award for Best Rock Album The ARIA Music Award for Best Rock Album, is an award