EXPLORATION GUIDES. Mineral chemistry is used extensively to help determine whether the kimberlite source is diamondiferous or barren (see other exploration guides). Diamondbearing kimberlites can contain highCr, lowCa pyrope garnets (G10 garnets), sodiumenriched eclogitic garnets, high chrome chromites with moderate to high Mg contents...
Get Price
Jan 29, 2017· •1 Block caving is the most commonly used method in excavating diamonds from kimberlite deposits. This method offers the highest yield and thus is the most cost effective. First, a large vertical hole is excavated, typically 1,750 feet (533 m) in diameter. Levels are .
Get Price
However, diamond grades of up to 100 carats/100 tons of kimberlite (1 carat/ton) were found in several pipes, which is considered competitive with larger deposits in countries such as Russia and Australia (McCallum Waldman, 1991).
Get Price
• Sulfide deposits: Massive sulfide deposits containing zinc, copper, iron, and trace amounts of silver are produced at the black smokers along the oceanic ridges, from which the hot, darkcolored, mineralrich water emerges as hot springs
Get Price
Oct 13, 2013· Venetia is the largest diamond producing mine in South Africa. It produced of diamonds from of ore in 2012. The deposit comprises of 12 kimberlite pipes. The mine is owned and operated by De Beers and has been in production since 1992.
Get Price
Only silicate minerals are considered mineral deposits. The concentrations of the elements in the deposit can be lower than the average concentrations in the crust. Mineral deposits can only be mined using strip mining techniques. The profitability of a deposit can change if the market price of that metal changes.
Get Price
Many kimberlite pipes also produce rich alluvial or eluvial diamond placer deposits. About 6,400 kimberlite pipes have been discovered in the world, of those about 900 have been classified as diamondiferous, and of those just over 30 have been economic enough to diamond mine.
Get Price
It also indicates that the posteruption infill of the pipe may be disrupted by the volcanic activity of nearby kimberlite pipes. Studies are in progress to determine the emplacement temperature of other ventfill lithofacies, such as dense, coherent pyroclastic kimberlite .
Get Price
S 84 NU 85 The discovery of a pyroclastic flow deposit within a kimberlite pipe, which 86 have been recently described elsewhere (Moss et al., 2008; Porritt et al., 2008), 87 places additional constraints on the dynamics of kimberlite eruptions and al lows comparisons with the deposits of pyroclastic flows from other better un MA 88 89 ...
Fossils may be found in these sediments. Some epiclastic deposits have been replaced with chalcedony, evidence for latestage volcanic hotspring activity. 2) Diatreme Facies Kimberlite Kimberlite diatremes are 12 kilometer deep, generally carrotshaped bodies which are circular to .
Get Price
Apr 15, 2013· Kimberlite Deposits. Epigenetic Primary: Diamond Secondary: NA Other: Kimberlite Indicator Minerals (KIM) Host: Kimberlite Process: Formed in depths over 100 km under the temperature of 900 – 1200 C and high pressure. Ideal conditions are in the old, cold, thick Archean (> Ga). Rapid igneous intrusions known as Kimberlite pipes.
Get Price
Diamond Mines. Kimberlite is the name of the blue rock that occurs in ancient volcanic pipes and is the most common host of diamonds. Sometimes the Kimberlite host rock is washed away by streams and rivers and diamonds are deposited as sediment in the stream sands in ''placer deposits'' which also called Alluvial deposits.
Get Price
Kimberlite weathering – complex issues Jarek Jakubec Indicator testing of kimberlite weathering 5 "I t is not a rock" somebody at a diamond mine said about kimberlite. Of course, technically speaking, he was not right, but sometimes I wonder if we really are dealing with rocks. The physical properties of kimberlite can be extremely
Get Price
FORMATION. One of nature''s most unique and dazzling gifts, diamonds come from two types of deposits. Primary deposits generally consist of diamondbearing "pipes" of a volcanic rock called "kimberlite." From deep in the earth these deposits were carried to the surface in molten rock, known as magma.
Get Price
Figure 2 Simplified schematic geology of three contrasting types of kimberlite pipes reconstructed to the time of emplacement (as shown in Fig. 1 and in the order of discovery). Pink dashed line = present surface. Country rock: grey = shale, orange = siltstone, cream = carbonates, pink = basement.
Get Price
Geophysical methods are particularly useful in diamond exploration. They tend to work well because kimberlite pipes, the diamond hosting rock, generally have properties that are different from the surrounding addition, the data provide most of the guidance on where to position drillholes.
Get Price
Kimberlite is an amazing and beautiful mineral which was propelled at rapid speeds from the earth''s core in mini eruptions throughout millions of years. These eruptions created conditions for the Kimberlite pipes (channels of the volcanic activity) to carry diamonds and many other minerals to the surface.
Get Price
Kimberlite, a variety of ultramafic volcanic and subvolcanic rock, is the dominant source of diamonds worldwide. It is widely accepted that the majority of diamonds are not formed within the kimberlite and much evidence points towards an ancient origin for most diamond in the deep lithospheric keels of Archaean cratons.
Get Price
Prairie Creek Kimberlite Overview. "Prairie Creek Kimberlite" is a producer magmatic vein deposit site discovered in 1906 in the Atlantic Plain of Arkansas, The United States. It is a medium deposit, not considered to be of worldclass significance. Diamond deposits .
Get Price
May 17, 2014· kimberlite and diamond natural. This feature is not available right now. Please try again later.
Get Price
Kimberlite, also called blue ground, a darkcoloured, heavy, often altered and brecciated (fragmented), intrusive igneous rock that contains diamonds in its rock matrix. It has a porphyritic texture, with large, often rounded crystals (phenocrysts) surrounded by a finegrained matrix (groundmass).
Get Price
Small kimberlite pipes, generally less than 1 hectare in area, are known in Guinea, Sierra Leone, and Liberia. Exploration for larger bodies has been severely hampered by thick tropical vegetation, and the lack of distinct geophysical contrasts between weathered kimberlite and the nonresponsive nature of countryrock granites and granodioritic gneisses.
Get Price
The Crazy Eruptions That Spit Up Diamonds. Even at its thickest, the crust is only ~70 kilometers thick, but the source of kimberlite magma is likely over 200 kilometers down. So, in kimberlite deposits, we find all sorts of chunks of mantle rocks and minerals, along with chunks of the crust that the kimberlite blasted through (we call these chunks "xenoliths"—foreign rocks).
Get Price
Kimberlite Diatremes. If diamonds are formed at depths of 150 to 200 kilometers in the upper mantle, how do they get to the surface of the earth? They are brought to the surface in a peculiar igneous rock called kimberlite (named after the diamondbearing region of Kimberly, South Africa where these rocks were first identified).
Get PriceNov 27, 2005· And this is not the only Kimberlite deposit, found in this arid alpine environment. There are at least 4 nearby claims that have produced diamonds in Colorado and at least four others just north in Wyoming. More info here Map (of sorts) of the Kelsey Lake area found here Worldwide only 14% of Kimberlite deposits are diamondiferious.
Get Price
Koala is predominantly infilled by a series of six distinct clastic deposits, the lowermost of which has been intruded by a late stage coherent kimberlite body. The clastic facies are easily distinguished from each other by variations in texture, and in the abundance and distribution of the dominant components.
Get Price