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
Tianshan Volcanic Group Chinese army) said that when climbing the Tianshan Mountains, saw "The Fire Mountains which send out masses of molten rock which flow for many Li" Tianshan Volcanic Group The Tianshan Volcanic Group is a volcanic field in the Tianshan Mountains in Northwest China. The historically active Cone of Pechan is within the group (also known as Peishan, Baishan, Hochan, Aghie, Bichbalick, Khala, and Boschan). The volcano is 440 km southwest of Urmqui, Xinjiang. Two eruptions are known from Tianshan, in 50 AD (± 50 years)and 650 AD (± 50 years). The book, Aspects of Nature in Different Lands and Different