Kimberlite pipe is a vertical or close to such a geological body, which was formed as a result of a breakthrough through the earth's crust of gases. This pillar is truly gigantic in size. The kimberlite pipe has a shape that resembles a huge carrot or a glass. Its upper part is a giant conical bulge, but with depth it gradually narrows and finally turns into a vein. In fact, such a geological body is a kind of ancient volcano, the terrestrial part of which was largely destroyed due to erosion processes.
What is kimberlite?
This material is a rock that consists of phlogopite, pyrope, olivine and other minerals. Kimberlite is black in color with a greenish and bluish tint. Presentlymore than one and a half thousand bodies of the mentioned material are known, ten percent of which belong to the diamond rock. Experts note that approximately 90% of all reserves of diamond sources are concentrated in kimberlite pipes, and the remaining 10% - in lamproite.
Mysteries related to the origin of diamonds
Despite a lot of research in the field of diamond deposits, modern scientists are still unable to explain some of the features associated with the origin and existence of these precious stones.
The first riddle: why is a 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 bas alts, granites, etc. What kind of force is needed to make such a breakthrough?! Why does a kimberlite pipe pierce precisely a powerful platform, and not thinner, say, the ocean floor, which is only ten kilometers thick, or transition zones - at the borders of oceans with continents? After all, hundreds of active volcanoes are located in these areas … 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 stem that goes into the depths.
The third mystery concerns the unusual shape of minerals in such rocks. All mineralswhich crystallize under the conditions of molten magma form well-cut crystals. Examples are apatite, zircon, olivine, garnet, ilmenite. They are widely distributed in kimberlites, but they do not have crystalline faces, but resemble river pebbles. All attempts by geologists to find an answer to this riddle have come to nothing. At the same time, diamonds located next to the mentioned minerals have the ideal shape of octahedrons, which are characterized by sharp edges.
What was the name of the first kimberlite pipe
The first of such geological bodies that were found and mastered 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 pipe is called the "Big Hole", it is considered the largest quarry that people have 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 produced 2,722 micrograms of diamonds, or 14.5 million carats. About 50 thousand people worked in the quarry, who, with the help of shovels and picks, 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 depth of the quarry was 240 meters, but after mining was completed, it was covered with waste rock. Currently, the "Big Hole" is an artificial lake with a depth of only 40 meters.
The biggest 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, the size of which was 32 hectares. And a year later, a second kimberlite diamond pipe was found in Yakutia, it was given the name "Mir". The city of Mirny grew up around this deposit. To date, the mentioned kimberlite pipe (the photo will help the reader to imagine the grandeur of this diamond deposit) is considered the largest in the world. The depth of the quarry is 525 meters, and the diameter is 1.2 km. Open pit diamond mining was discontinued in 2004. An underground mine is currently under construction to mine the remaining reserves, which are dangerous and unprofitable to mine. According to experts, the development of the tube in question will continue for at least another 30 years.
History of the Mir kimberlite pipe
The development of the deposit was carried out in harsh climatic conditions. In order to break through the permafrost, it was necessary to blow up the rock with dynamite. Already in the 60s of the last century, the deposit produced 2 kg of diamonds per year, and 20 percent of them corresponded to gem quality and, after cutting, came to jewelry stores as polished diamonds. The rest were used for industrial purposes. From 1957 to 2001, diamonds were mined in the Mir quarry, the total value of which was $17 billion. In this periodThe quarry expanded so much that trucks had to travel 8 kilometers from the surface to the bottom on a spiral road. Helicopters, on the other hand, were strictly forbidden to fly over the object, since a huge funnel simply sucks in all aircraft. The high walls of the quarry are also dangerous for land transport and people working in the mine: 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. The space of the future city is planned to be divided into tiers: the upper one is for a residential area, the middle one is for creating a forest park zone, and the lower one will have an agricultural purpose.
Conclusion
Diamond mining has a long history. As new deposits were discovered and explored depleted, leadership passed first from India to Brazil, and then to South Africa. At the moment, Botswana is in the lead, followed by Russia.
