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Kimberlite pipes are the most important source of mined diamonds today. The consensus on kimberlites is that they are formed deep within Earth's mantle . Formation occurs at depths between 150 and 450 kilometres (93 and 280 mi), potentially from anomalously enriched exotic mantle compositions, and they are erupted rapidly and violently, often ...
The ML rocks are not considered to be archetypal kimberilte and have been variously classified as alkaline ultramafic rocks, hybrid alkaline ultramafic rocks, alkali olivine basalt and basanite; they are difficult to classify because of strong clay alteration that has obliterated most of their original mineralogy.
The ML pipes form part of the Northern Alberta kimberlite province, along with the nearby Birch Mountains kimberlite field and the Buffalo Head Hills kimberlite field.They were discovered in 1989-90 just north of Mountain Lake (55.456291n 117.714510w), which lies about 75 km (47 mi) northeast of Grande Prairie, Alberta.
Lamproite pipes operate similarly to kimberlite pipes, except that the boiling water and volatile compounds contained in the magma act corrosively on the overlying rock, resulting in a broader cone of eviscerated rock (the ejection of this rock also forms a tuff ring, like kimberlite eruptions). This broad cone is then filled with volcanic ash ...
It is generally accepted that the pipe was emplaced about 180 million years ago. The lake Ellen Kimberlite is popular with rock hounds as the classic indicator minerals (pyrope, magnesian ilmenite and chrome diopside) for kimberlite are easily found in the material, though few are of gem quality and size. While there was considerable interest ...
The Birch Mountains kimberlite field is a cluster of kimberlitic volcanic pipes or diatremes in north-central Alberta, Canada that were emplaced during a period of kimberlitic volcanism in the Late Cretaceous epoch. [1] As of 2011, 8 diatremes had been discovered in the field, and diamonds and microdiamononds had been recovered during sampling ...
Kimberlite pipes form when kimberlite magmas rise considerably from depths as great as 400 kilometres (250 mi). [83] As the kimberlite magmas approach a depth of at least 2 kilometres (1.2 mi), the magma explodes violently through the Earth's crust, carrying fragments of rock that it has collected along the way and, in the right conditions ...
Diavik Diamond Mine is an industrial complex set in a remote, subarctic landscape. [2] It consists of four kimberlite pipes associated with the Lac de Gras kimberlite field and is located on an island 20 km 2 (7.7 sq mi) in Lac de Gras informally known as East Island.