Aug 12, 2014· The proportion of gem quality diamonds tend to be quite pronounced in alluvial deposits, whereas the primary source kimberlite pipes tend to have a wider range of qualities, including a ...

KIMBERLITE. Kimberlite is a plutonic igneous rock famous as the host rock for diamonds. It is named for the South Africa town of Kimberley where a large kimberlite pipe has been mined for large volumes of diamonds. Kimberlite is always found as volcanic pipes over deep (ancient) continental crust.

Kimberlite is generally poor in the minerals most often found in igneous rocks because it forms at extreme depths. Rising from 100 to 135 miles under the surface, kimberlite magma tends to scrape other rock types from the walls of its chamber and incorporate them into its matrix. This process is responsible for its very rough, asphaltlike texture.

Kimberlite pipes form by explosive disruption and deformation of country rocks. Confinement in a pipe introduces new processes such as fluidization, dynamic sintering, and intense mixing between volcanic jets and concentrated trapped mixtures. Occurrences of extravent and craterfill lithofacies indicate that kimberlite eruptions generate ...

Near the surface, kimberlite is found in clusters of pipelike bodies called diatremes. Mine workings show that they coalesce at depth and link up with dykes of nonfragmental kimberlite.

Kimberlitenearly vertical, cylindrical body or opening in the rock, near the surface. kimberlite pipes are found in clusters, at depths they link up with dykes, a wall like body of igneous rock formed as the effect of having been pushed up into a crack in a heated or liquid condition.

Alrosa, the world's leading diamond miner, has operations in Republic of Sakha (Yakutia) and Arkhangelsk region, running 11 kimberlite pipes and 16 alluvial deposits in the harsh climate of the Russian Far North.

Dec 16, 2016· Several kimberlite pipes occur in the Kimberley area. Kimberlites have a gently taperingdownward, pipeshaped crosssection. Lamproites have a crosssection more closely resembling that of a martini glass. The rock seen here is from a nondiamondiferous kimberlite intrusion in Pennsylvania.

mechanism of kimberlite pipes. The one model, termed the "magmatic model", operates with an assumed high volatile content in a kimberlite magma rising to shallow preeruptive subsurface levels. Fluids are concentrated at the tip of the rising kimberlite magma column and are initially prevented from breakthrough to the surface by the

Diamonds are brought to the surface from the mantle in a rare type of magma called kimberlite and erupted at a rare type of volcanic vent called a diatreme or pipe. Kimberlite is a gasrich, potassic ultramafic igneous rock that contains the minerals olivine, phlogopite, diopside, serpentine, calcite, and minor amounts of apatite, magnetite, chromite, garnet, diamond, and other upper mantle minerals.

Kansas kimberlite, for example, intruded during the Cretaceous period, 90 million years ago. The intrusions form pipelike structures as the magma cools. The kimberlite pipes of the Kimberley region are vaguely funnelshaped, being wider nearer to the surface and getting thinner and thinner at .

Kimberlite pipes are the most important source of mined diamonds today. The consensus on kimberlites is that they are formed deep within the mantle. Kimberlite occurs in the uplifted centres of continental platforms. In the Kimberley district, South Africa, it forms pipes and, occasionally, dikes.

Shengli pipes, Wangcun deposit, Changma Kimberlite belt, Mengyin Kimberlite field, Mengyin Co., Yimeng Mts, Linyi Prefecture, Shandong Province, China A rare specimen of Diamond in Kimberlite from one of the Shengli Pipes, China.

Kimberlite definition, a variety of micaceous peridotite, low in silica content and high in magnesium content, in which diamonds are formed. See more.

that kimberlite dykes are connected to the deep source and that the pressuregradientbetweenthesourceandthedyketipisgovernedby the release of copious carbon dioxide (CO

While small compared to the great diamondbearing kimberlite pipes of the African continent or more recent discoveries in northern Canada, Colorado is nonetheless endowed with a relatively substantial kimberlite district, many of which contain diamonds. With a history of exploration spanning a mere ~45 years, the Stateline District of northern Colorado and adjacent southeastern Wyoming is an exciting .

The Mir Kimberlite Pipe was the first diamondiferous kimberlite found in Siberia and one of the most important diamond mines on Earth. The Mir Kimberlite is one of several ultramafic pipes in the MaloBotuoba Kimberlite Field of the Siberian Platform. Additional diamondiferous kimberlite fields have been found elsewhere in Siberia.

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The KimberliteDiamond Connection . Kimberlite is a rock type first categorized over a 100 years ago based on descriptions of the diamondbearing pipes of Kimberley, South Africa. Kimberlite is characterized as a hybrid, volatilerich, potassic, ultrabasic igneous rock.

Kimberlite pipes are often only a few hundred meters across so from a geologic standpoint it wouldn't take much to completely obliterate it. On the other hand, the long term stability of cratons allows the narrow pipe geometry to remain intact.

Kimberlite block. Kimberlite with diamonds. Kimberlite is an igneous rock type that can be found as pipes in of the kimberlite pipes contain diamonds. The former diamond ore block is replaced with blocks of kimberlite with diamonds in this mod.

Jun 20, 2008· However, the Jwaneng Centre Pipes are unusual amongst Southern African kimberlites (Class 1 kimberlite). Two key differences are the juvenile clast morphology and the absence of microlitic diopside in the matrix of the volcaniclastic deposits ( Field and Scott Smith, 1999, Webb et al., 2003, Skinner and Marsh, 2004 ).

The 'classic South African model' of a kimberlite pipe (Mitchell, 1986) with old nomenclature (left side of figure) and a simpler, revised twofold nomenclature system (right side of figure) to ...

KIMBERLITE PIPES AND INTRUSIVES IN DIATREMESMassive porphyritic to brecciated intrusive masses and dikes. Several diatremes contain diamonds, xenoliths of Silurian and Ordovician limestones and dolomites, fragments of Precambrian crystalline rocks, and xenoliths of peridotite, westerite, and eclogite.

Welcome to the Diamond Exploration Laboratory Our Research. The Diamond Exploration Lab carries out petrological and mineralogical studies of kimberlites, mantle xenoliths and diamonds to uncover the structure, thermal regime and processes in the diamondiferous upper mantle.