A kimberlite pipe is a vertical or close to such a geological body, which was formed as a result of a breakthrough of gases through the earth's crust. This pillar is truly gigantic in size. The kimberlite pipe has a shape that resembles a huge carrot or glass. Its upper part is a giant conical-shaped inflation, however, with depth it gradually narrows and finally passes into the vein. In fact, such a geological body is a kind of ancient volcano, the ground part of which was largely destroyed due to erosion processes.
What is kimberlite?
This material is a rock, which consists of phlogopite, pyrope, olivine and other minerals. Kimberlite is black with a greenish and bluish tint. Currently, more than one and a half thousand bodies of the mentioned material are known, ten percent of which are related to diamond rock. Experts note that approximately 90% of all diamond source reserves are concentrated in kimberlite pipes, and the remaining 10% are in lamproite pipes.
Puzzles related to the origin of diamonds
Despite the many studies carried out in the field of diamond deposits, modern scientists are still not able to explain some of the features associated with the origin and existence of these gemstones.
The first riddle: why is the kimberlite pipe located exclusively on ancient platforms and shields, which are the most stable and stable blocks of the earth's crust? After all, the thickness of these layers reaches 40 kilometers of rock, consisting of basalts, granites, etc. What kind of strength is needed to make such a breakthrough ?! Why does a kimberlite pipe pierce precisely a powerful platform, and not a thinner, say, ocean floor, whose thickness is only ten kilometers, or transition zones - at the borders of the oceans with continents? Indeed, hundreds of active volcanoes are located on these sites … Geologists are not able to answer this question.
The next mystery is the amazing shape of the kimberlite pipe. In fact, it does not look like a pipe at all, but rather like a champagne glass: a huge cone on a thin leg that goes deep.
The third riddle concerns the extraordinary form of minerals in such rocks. All minerals that crystallize in molten magma form clearly faceted crystals. Examples include apatite, zircon, olivine, pomegranate, ilmenite. They are widespread in kimberlites, but at the same time they do not have crystalline faces, but resemble river pebbles. All attempts by geologists to find an answer to this riddle have led to nothing. At the same time, the diamonds located next to the mentioned minerals have an ideal octahedron shape, which is characterized by sharp edges.
What was the first kimberlite pipe called
The first of these geological bodies, which was found and developed by people, is located in the south of the African continent in the province of Kimberley. The name of this area has become a household name for all such bodies, as well as rocks containing diamonds. This first tube is called the "Big Hole", it is considered the largest career that people developed without the use of technology. Currently, it has completely exhausted itself and is the main attraction of the city. From 1866 to 1914, the first kimberlite pipe gave developers 2722 micrograms of diamonds, which amounted to 14.5 million carats. About 50 thousand people worked in the quarry, and with the help of shovels and picks they extracted about 22.5 million tons of soil. The development area is 17 hectares, its perimeter is 1.6 km and its width is 463 m. The pit depth was 240 meters, but after the end of production it was covered with waste rock. Currently, the "Big Hole" is an artificial lake, the depth of which is only 40 meters.
The largest diamond quarry
Diamond mining in Russia began in the middle of the last century with the discovery in 1954 of the Zarnitsa deposit on the Vilyui River, which amounted to 32 hectares. A year later, the second kimberlite diamond pipe was found in Yakutia, it was given the name "Mir". The city of Mirny has grown around this field. To date, the mentioned kimberlite pipe (a photo will help the reader to imagine the grandeur of this diamond deposit) is considered the largest in the world. The quarry depth is 525 meters and the diameter is 1.2 km. Open pit mining was discontinued in 2004. An underground mine is currently under construction to mine the remaining reserves, the open pit mining of which is dangerous and unprofitable. According to experts, the development of the tube in question will continue for at least another 30 years.
The history of the kimberlite pipe "Mir"
Field development was carried out in severe climatic conditions. In order to break through the permafrost, it was necessary to explode the rock with dynamite. Already in the 60s of the last century, the deposit produced 2 kg of diamonds per year, with 20 percent of them meeting the jewelry quality and, after cutting, they went to jewelry stores as diamonds. The rest were used for industrial purposes. From 1957 to 2001, diamonds were mined in the Mir quarry, with a total value of $ 17 billion. During this period, the quarry expanded so much that freight transport had to drive 8 kilometers from the surface to the bottom along a spiral road. Helicopters were strictly forbidden to fly over the object, since a huge funnel simply sucks in all the aircraft. Tall walls of the quarry are also dangerous for land transport and people working in mining: there is a threat of a landslide. Today, scientists are developing an eco-city project, which should be located in a quarry. To do this, it is planned to cover the pit with a translucent dome, on which solar panels will be installed. They plan to divide the space of the future city into tiers: the upper one is for the residential zone, the middle one is for creating a forest park zone, and the lower one will be for agricultural purposes.
