September 7, 2012 20:36
Diamonds — soot from the chimneys of hell
Annually from kimberlite pipes in the world produces about 25 tons of technical and gem diamonds in the rough cost of about $ 12 billion. Lives of tens of millions of people in one way or another connected with diamonds: they are looking for them, extract, process, sell. Diamonds are not only to meet the immense human vanity and desire for shiny expensive trinkets.
It is estimated that the use of diamond tools more than doubles the economic potential of any developed country. But a simple question: how diamonds are formed in nature? — No response so far. It is believed that diamonds were crystallized in the unknown depths of the mantle and kimberlite "pipes bang" carried to the surface of the planet. In the standard version it is not clear all: the mechanism of the formation of diamonds, and the placement of the planet diamondiferous rocks — kimberlites, and causes "kimberlite pipes", rooted in the depths of the earth.
Diamonds and diamond-bearing rocks of the mantle — kimberlites devoted thousands of scientific articles. But they do not respond to three major puzzles of indigenous diamond deposits. First: why kimberlites are located only on the "platform", the most stable and powerful blocks of the Earth's crust? What monstrous forces caused heavy rock mantle to break the great law of buoyancy, to rush up and punch, as armor-piercing shell of unprecedented power, 40 kilometers lighter rocks — basalt, granite and sedimentary rocks? And why kimberlite pipes "pierce" is a powerful platform crust, not thin crust 10-kilometer ocean floor or the transition zone at the boundary of the continents to the oceans, where the deep faults smoke hundreds of volcanoes and lava flows freely to the surface? .. Answer by geologists not.
Another mystery is a wonderful form of kiberlitovyh tubes. In fact, this is not the "tube", but rather "champagne glasses" cones on his thin legs, disappearing into the depths of the planet. Geologists call them "tube explosion," although it is hard to imagine a more ridiculous phrase: for underground explosions form is not the tube and the sphere! Who drilled numerous so-called "kamufletnye camera" — void left by powerful underground nuclear explosions. All of these cameras have a spherical shape. But it kimberlite "pipe-cones" do exist! How did they come from? The answer is none.
The third puzzle for an unusual form of mineral grains in kimberlites. It is known that the minerals are the first to crystallize from molten rock, always form a well-cut crystals. These minerals include apatite, garnet, zircon, olivine, ilmenite. They are common in kimberlites, but here they are always absent crystal faces, the grains are rounded and the shape of a rounded pebbles. Geologists try to explain this enigmatic feature that minerals were melted hot magma. Melting, as we know, leads to the transformation of minerals into the amorphous glass, devoid of crystalline structure. However, no trace of "vitrification" and the loss of the crystal structures of these rounded grains none has been found.
But the diamond crystals are at concentrators whole mountains gleaming, perfectly formed octahedral or rhombic dodecahedron with sharp edges, which are so easy to cut glass. But they are, in current theory, originated in the depths of the mantle and were made already "off the shelf" with kimberlite magma from depths of 150-200 kilometers. These crystals somehow survived, despite the fragility, the abundance of internal stresses and the ability to easily split on certain planes
It turns out that the diamond crystals, the last very long and thorny path of molten magma, look like they just rolled off the assembly line. But the crystals of garnet, zircon, apatite and other minerals, as if released from the melt directly into the tube, deprived of their respective sides. Why there was such a paradox?
Extensive analytical and experimental data allowed me to propose a new model for the formation of kimberlite pipes and diamonds, which can explain the mysteries of these geological formations sverhglubinnyh. The model is developed based on extensive information about the gas, mostly hydrogen and methane "exhale" mantle, and possibly Earth's core.
Kimberlite pipes are invited to consider the traces left by "puncture" rises from the mantle lithosphere huge gas bubbles. Bubble gas mantle finds its way out through a thin needle solid crystalline basement rocks platform, and then forms the extension — "glass" — in the surface soft sediments. Deep gas pushes the terrible pressure of tens of thousands of atmospheres, transferred from the mantle to the upper part of the crust on the thin tube "puncture" about the same as the pressure is transmitted through the tubes of oil hydraulic drive vehicle.
The association of kimberlite to the platforms I explain the fact that the platform are gas-tight structures, promotes accumulation beneath rocks scattered in tiny bubbles of gas in large bubbles of hydrogen-methane composition. At a certain critical, the amount of such a bubble begins to float to the surface. Deep degassing of the Earth billions of years continues, and volcanologists believe that the most active, it is manifested in volcanic belts surrounding stable block platforms.
Platforms like the saucer floating in an aquarium, which rise from the bottom of the air bubbles. Bubbles flow around the saucer, but some of the gas accumulates under his bottom. Constantly smoldering volcanoes — direct evidence of the abundance of gases generated by deep-seated faults of the lithosphere. On the depth of gas indicated by the fact that helium is strongly enriched light deep isotope He-3. But in a gas platforms He-3 is a thousand times smaller than in the gas eruptions and this means that the platform — impermeable cap for deep gas mantle.
In my opinion, the reason that causes diffuse mantle gas flows into pop bubbles with a "critical" volume is the powerful impact of "hot spots," deep "jets" associated with the liquid core of the Earth and burning solid lithosphere. For example, the current "hot spot" seared right through the thin crust of the Pacific Ocean and created the volcanoes of Hawaii. This "jet" has worked in the same place for 70 million years ago, and from its activities was a giant seam of solidified basaltic lava. Imperial is an underwater ridge. It stretches thousands of miles from Hawaii to the Aleutian Islands and noted the progress the Pacific Plate to the north-west.
Volcanoes — it is like the earth existing chimneys. They are working properly, if the path of gases do not overlap "flap". In the history of the Earth's most often these dampers are the driving platform. Cora platform is so powerful, that the "hot spot" is not enough energy to burn it. But energy is sufficient to melt the rocks at depth and to collect the scattered microscopic inclusions in these gases in large bubbles with a "critical" of about a cubic kilometer.
As you know, the tiny droplets of fat in milk is not emerge as long as the energy is not blind churn of them a considerable amount of oil. When the "hot spots" will form a platform large gas bubbles, comes into play Archimedes. Density of the H2-CH4 even at a pressure less than the mantle of water. But the density of the mantle more than three times greater than the density of water. Hence, the lift bladder volume of 1 cubic kilometer of 2.5 billion tons! And this red hot gas to 600-800 0C!
Narrowing of kimberlite at depth in a thin "legs" — an indication that the whole huge lift gas is applied to a very small area, creating the effect of a needle that can puncture the tens of kilometers of rock. On thin channel length of 150-200 km mantle gas bubble breaks up, have not yet implemented in the soft sedimentary cover rocks. We can say that the mantle like "inserts an enema" powerful earth's crust, resulting in sedimentary rocks parted, and cone shaped kimberlite pipe.
Floating gas bubble creates a zone of low pressure in its tail, recrystallized under the influence of the gas mantle rocks are crushed, and the rush to the small sample. Gas drags mantle rocks, like a lifeguard, who were dragged by the hair out of the water drowning. As in the giant sand car, mineral grains in the infernal race convection currents of the gas mixture, which geologists call fluid. The crystals abrade, lose crystal face and turn into deep gravel supercritical gas stream, almost indistinguishable from the normal river pebbles.
But microscopic examination shows that there are differences: the impact of the hot gas jet creates a special matte surface deep kimberlite minerals known among geologists as "sharkskin". With an increase in the thousands of times shows that corrosion is microporous structure, which resembles a sponge. Similar structures occur when exposed to hot gases on the surface of meteorites or gas turbine blades. Studies of apatite, zircon and other minerals have shown that they hold a "memory" of the ignition of the gas in a reducing environment.
The question is: why is it so beautifully faceted diamond crystals? After all, it is believed that the magma get them out of the "stone caves" cloak and dragged more than a hundred kilometers. And their hardness does not help: it is known that the diamonds in the deposits of rounded and chipped, since this mineral is brittle. The textbooks are the equilibrium diagram of diamond-graphite and says that there is a diamond from graphite. But no one asks the question: where does the mantle took graphite? After graphite — forbidden mineral for the conditions of the mantle. Here stable carbides of iron, phosphorus, silicon, nitrogen, and … hydrogen. Carbide hydrogen — is a regular methane. Unlike other carbides is a gas, it is mobile and easy to concentrate in the deep fluid.
It is true that tens of tons of industrial diamonds synthesized from liquid iron saturated with carbon. Synthesis is because the melt at 1200 0 C and a pressure of thousands of atmospheres become undersaturated by solubility in graphite and diamond supersaturated solubility. Of course, the natural process is not similar. But geologists do not pay attention to the remarkable discovery of Soviet physicist Boris Derjaguin, who in 1969 received a diploma from the opening of the USSR for the synthesis of diamond from methane at a pressure lower than atmospheric pressure, even!
This discovery radically changes the existing ideas about diamond as a mineral, crystallizing necessarily from melts at high pressures. It allowed me to consider the possibility of diamond crystallization of the fluid and the gas mixture in the system C-H-O. It turns out that in such a fluid oxygen at ultrahigh pressures mantle loses its oxidizing properties and does not oxidize even hydrogen. But with the rise of gas up, the formation of a kimberlite pipe pressure drops. Enough to reduce the pressure of 10 — 50 to 5 kbar to oxygen activity has increased a million times: it instantly oxidizes hydrogen and methane. Simply put, the gas ignites and underground pipe breaks out the fire!
Outcome underground fire depends on the ratio of carbon, hydrogen and oxygen in the fluid. If oxygen is not too much, it will pull out of the methane molecule CH4 only hydrogen, and emerged with the water vapor absorbs mineral dust to form serpentinite, characteristic mineral kimberlite. Remaining single ionized carbon at a pressure of thousands of atmospheres and a temperature of about 1000 0C closes unsaturated covalent bonds "on itself" with the emergence of giant molecules of pure carbon, which we call the diamond.
Favorable for the occurrence of diamonds combination of components is rare: only 3-5% are diamondiferous kimberlite pipes. With an excess of oxygen to burn methane not only hydrogen but also carbon, which will turn into oxides — CO or CO2. So there are barren kimberlites differ enhanced magnetic due to the appearance of iron oxide — magnetite. This means that the oxygen was so much that he even "ripped" from the iron silicates. If a diamond appears as a product of spontaneous underground combustion of hydrogen in carbon fluid, the clear crystals of carbon — simply "ash" or "black", they settled in the "chimney" of the mantle.
Experiments on explosive synthesis show that diamonds grow for a few thousandths of a second — almost instantly. So, in the methane fluid around the "swallowing" gaseous carbon crystals, a zone of low pressure, which dramatically increases the activity of oxygen. It can be assumed that the crystallization is accompanied by numerous outbursts, explosions. Crystallization promotes extremely high thermal conductivity of diamond, allows you to quickly equalize the temperature of the crystal. Indeed, the authors of patents, where it is assumed the diamond crystallization, with the participation of the gas phase, say the explosions in the crystallization chamber. It may be that in the dark dungeons birth diamonds like flying fireflies.
The combustion of methane increases the oxygen activity and affects the isotopic composition of carbon and nitrogen that make up the diamond, as in oxidizing concentrated heavy isotopes. Analyses conducted on zonal diamond crystals from kimberlites show that the inside of the crystal enriched light isotope of carbon. It is known that light isotopes of carbon and nitrogen accumulated in a reducing environment, and heavy — in oxidizing. The sharp increase in the concentration of heavy isotopes of carbon and nitrogen in the outer zone of crystals shows how rapidly increases the oxidation potential for diamond formation.
The high thermal conductivity of diamond allows them to grow very quickly. Therefore, similar to the original diamond cans seized numerous inclusions of gas dust — mineral grains of plutonic rocks. Determination of the absolute age of the mineral inclusions sometimes coincides with the geological age of the kimberlite pipes, but most inclusions age is older. For example, in a tube, "Kimberly" in South Africa, working with the surrounding rock 85 million years ago, the age of pyrope garnet, certain samarium neodimievym method is 3200 million years old.
In Yakutsk tube "Lucky", broke through the surrounding rocks 425 million years ago, the age of the mineral inclusions of clinopyroxene defined potassium-argon method in 1149 million years, etc.
Geologists are usually made of such determinations concluded that diamonds crystallized in the mantle for a long time — billions of years ago, and explosions throw them to the ground. In our view, the inclusion of the ancient mantle minerals growing crystals were taken out of the dust fluid.
Of inclusions in diamonds mounted native metals — iron, nickel, chromium, silver, and nickel, and iron sulfides. How did they get to the diamonds? Obviously, these metals are taken from silicates with high content of iron, nickel, silver, and spinels with high chromium content as powerful reducing agents, as H2 and CO, and addition of hydrogen sulfide, which is characteristic for underground gases, turned some of these metals in the sulfides. Diamond "armor" retained volatile sulfide-metal dust in the form of impurities in the crystals.
Mystery to geologists long remained harsh "dry" contacts kimberlite pipes with the surrounding rocks.
Usually around arrays of igneous rocks occur thick zones of contact changes. And around kimberlites change sedimentary void. This phenomenon is related to the fact that the specific heat of gases that formed kimberlites in 2-3 thousand times lower heat capacity of silicate melt at the same level: the gas cools rapidly in contact with sedimentary rocks. At the same time, the contact changes around the kimberlite pipes are large, but they are unusual. Changes are seen in the fact that there are powerful around the tubes — up to a mile — halos concentration of tiny grains of luminescent minerals.
In the host sedimentary rocks in the tens and even hundreds of times increases the content of apatite and zircon grains — minerals, brightly glowing in ultraviolet light. Apatite and the lights are not the usual yellow due to the presence of Mn 2 +, and blue light due to the presence of Eu 2 +, which is typical for apatite kimberlites. These fluorescent halos due powerful blowing porous sedimentary rocks deep mantle gas having a pressure of thousands of atmospheres and carries the characteristic elements of kimberlites.
Birth of diamonds is not unknown in the "stone caves," and in the process of formation of kimberlite pipes explains preservation perfectly formed crystals of diamonds against kimberlite "pebbles", consisting of rounded, chipped edges and lacking depth minerals really recovered from the mantle. The crystallization of diamond from the gas also indicates the constant presence of nitrogen (up to 0.3%), and sometimes — boron. In the ultramafic rocks of the mantle is almost no nitrogen or boron, but these elements in the fluid sharply focused as a gaseous compound with hydrogen. Apparently accumulated in the fluid and radon, the presence of the past is evidenced by the sharp enrichment kimberlites radiogenic isotope of lead — Pb-206, arising from radon. That radon strong alpha-emitter, could create a mysterious green diamonds, whose color is associated with exposure to alpha particles.
Modern industry gets by partial oxidation of methane millions of tons of soot annually, 80% of the soot is the production of tires. A huge amount of soot deposited on the walls of countless pipes — furnace, factory, factory and it does not surprise anyone. But get used to the idea that a diamond — black, too, but the mantle, geologists difficult. This analogy seems to them blasphemous.
To a simplified analogy of kimberlite pipes with chimney does not harm the understanding of the natural process, I note that the kimberlite pipes are not formed volcanoes, did not go to the surface of the Earth and the sky is not smoked as pipes London H1H century. Kimberlite — not an igneous rock, and the analog volcanic tuff fluidiza remaining in the depths of the earth. Therefore the structure of it — not porphyry and breccia-conglomerates. If most are angular fragments of sedimentary cover. there is a breccia, and if a lot of deep mineral pellets — conglomerates. Globular education in kimberlites, similar to tennis balls and called "autoliths", in our opinion, "blinded" from the sticky dust serpentine gas flow in the deep hydration of crushed olivine with water vapor.
Mantle gas hung in the sedimentary layers of the Earth's crust, just like a balloon with a gas burner hangs in the atmosphere, the energy expended on the rise. Therefore, none of the geologists did not find volcanoes that spray around the diamond crystals. Kimberlite pipes are opened only by processes of erosion. For geologists, this means that there are many "blind" kimberlite pipes, do not go to the surface. Their presence can be identified by the presence of local magnetic anomalies, the upper edge of which is located at a depth of a hundred, and if you're lucky — even tens of meters. These unopened tube erosion keep diamonds for future generations of geologists.
Deep gold-"rivers" of the Earth
In 1877, the famous Austrian geologist Eduard Suess published an article which caused panic in the financial and industrial circles of the European states. The article considers the special commission the German Reichstag in the heated discussion was attended by many scientists — geologists, economists and historians. What is so excited about the public? It turned out Suess predicted the economic collapse of our civilization as a result of the coming of the inevitable shortage of gold — the basis of the global financial system at the time. After collecting data on known deposits of precious metal, its rate of production and consumption growth, it is calculated that there will soon catastrophic shortage of gold, because the demand is dramatically outpace supply.
However, the global currency crisis did not happen. Salvation came unexpectedly — from South Africa. In 1886, farmer Walker, who lived near the city of Johannesburg, said in a stone found a brass-colored sequins. Just in case it shattered rock and sand washed in a bucket of water. As often happens with novice miners, Walker was right: Cast in brass grains were mineral pyrite, iron sulfide (FeS2), have no special value. But Walker was incredibly lucky with pyrite at the bottom of the pelvis zmeilas thin bright yellow strip of the golden sand.
It was opened by the gold of the Witwatersrand, the world's greatest concentrations of precious metal. Subsequently, the value of the field has increased, as it turned out it together with gold concentrates and uranium. In the entire history of mankind has produced about 100,000 tons of gold, and half of it is extracted from the mines of the Witwatersrand. Sometimes here for a year to produce more than a thousand tons of gold. Thanks to the powerful flow of the South African gold global financial crisis did not happen.
Naturally, the unique gold mining giant has attracted worldwide attention, and geologists have tried to find its counterparts in other countries. The amazing feature of the field is a combination of simplicity, the geological structure and the complexity of intractable mysteries which arose in his study. Indeed, there are ore deposits layers of tightly cemented pebble conglomerates, very similar to the modern river or coastal marine gold placers.
Since the end of last century the bulk of gold mined from alluvial deposits of the Urals, Siberia, California, Australia and Alaska, the geologists who have studied the Witwatersrand, were convinced that South Africa's discovery of giant ancient deposits, accumulated in rivers Proterozoic geological epoch. This opinion was included in monographs and textbooks around the world.
But as the study of the Witwatersrand had questions for which there was no intelligible answers. For example, it is known that near the placer can find the remains of primary deposits, due to which these placers occur. In the nature of the ore bed Witwatersrand hosted about 100,000 tonnes of gold, at least the same amount of gold contained in the layers with non-industrial content.
We know that in placer goes only part of the original gold, and much of its wear and completely dissipated. Hence, in primary deposits, through which any ancient placers, there were at least 500,000 tonnes of gold!
Meanwhile, a major gold deposits called deposit with only a hundred — two hundred tons. This raises the obvious question: where are the thousands of large gold deposits, and numerous huge deposits of uranium?
South Africa has still not found the indigenous gut major types of gold and uranium deposits, and even if we assume that they are completely erased by erosion, then they are simply not there is enough space. Meanwhile, the calculations show that the ore field in the Witwatersrand area of 100 000 square meters. km Rich Gold reaches two tons per square kilometer! How was born the gold? Neither hypothesis can not identify the source of the demolition of such a monstrous amount of alluvial gold.
Another mystery for the composition of ancient gravels. Already a pioneer farmer Walker drew attention to the fact that conglomerates along with the mass of pebbles milky white quartz vein also contains a lot of pyrite. But usually pyrite forms beautiful crystals, and here he is so well-rounded that resembles balls. South African geologists call it "pyrite beads" or "grape", depending on the size of rounded crystals. And weathered ore mineral of uranium — uraninite. Mystery is that of pyrite and uraninite, as opposed to quartz, minerals, very unstable. On the surface of the Earth, they instantly oxidized collapse and disappear, so in modern river placers do not. Why rounded pyrite and uraninite allegedly preserved in river gravels of the Witwatersrand?
For a long time it was thought that the lower Proterozoic in the atmosphere there was no oxygen and therefore pyrite could survive in the river sediments. However, current analysis of oxygen isotopes in Proterozoic sediments give a definite answer: oxygen in the days present in the atmosphere in considerable quantities. Proof of this are, in particular, many kilometers thick layers of sedimentary banded iron Proterozoic consisting of iron oxide — hematite. Such "rusty" precipitation occur only in the presence of oxygen-rich atmosphere, when pyrite crystals simply do not have time to become pebbles — they turn into oxides and hydroxides of iron rust.
Meanwhile pyrite pebbles of quartz pebbles Witwatersrand so much that a year is extracted 500,000 tons of pyrite to produce sulfuric acid. And the price is rounded uraninite produced 10% of the value of gold. Why are preserved in the deposits of minerals which are unstable in the earth's surface? The answer to this question is no.
Finally, it was an amazing mystery age ore. Exploration has identified about two dozen layers that lie on top of each other in a 10-km thick ancient sediments — sandstone and shale. The lower layers of the stratum are aged 2.5 billion years, and the top — 1.9 billion, ie 10 kilometers of precipitation accumulated here over 600 million years. Meanwhile, all of the many layers of ore pebbles are of the same age — about 1.9 billion years old, regardless of where they occur: in the lower or upper section of the host rocks. No geologist can not explain why the ancient sands and clays interbedded with younger gravels. Because it is contrary to the geological concepts of the laws of the formation of sedimentary strata.
To explain this paradox, the geologists were forced to assume that in the course of the late rock alteration of easily changing uraninite, which define the age of conglomerates was submitted part of radiogenic isotope Pb-206, and this uraninite like "rejuvenated" to 1.9 billion years. However, the age of the accompanying uraninite more sustainable radioactive mineral — monazite also was close to the age of uraninite. Was set even more amazing fact: ore pebbles with age (as uraninite and monazite) in 1.9 billion years intersected veins with galena, lead sulfide, which was so much radiogenic isotope of lead Pb-206, that his age was estimated at intervals 2.5 — 3.8 billion years old.
How is this possible? Can there be younger grandson grandfather? .. And what is the river that there is 600 million years old and regularly lay by ore conglomerates? After all, the life of the rivers on the earth's surface is small — only a few million years … to solve all mysteries were so many that it just stopped discussing. In the geological literature, even the term "mystery of the Witwatersrand" without any hint of their permit.
Despite all these puzzles, geologists continued to believe Witwatersrand giant river loose. This went on for as long as the intelligence has not revealed in Central Asia on the ridge Kuramin large gold deposits in the volcanic rocks of the Carboniferous period. 300 million years ago a fire-breathing mountains rose like Kluchevskoy. Now from volcanic cones nothing left — they are destroyed by erosion, but near the surface of the ore-bearing deep were their "roots", where in the cracks of andesite lava of saline solution at a temperature of about 300 0C was a process of deposition of native gold.
The ore bodies here were of two types: in the form of conventional quartz-pyrite veins and as the later ore columns very unusual composition, which broke through the quartz veins. The unusual ore columns was that they were packed rounded fragments of different rocks. Here andesite boulders and pebbles mixed with fragments of quartz veins and they were firmly cemented late pyrite and quartz with a touch of gold.
And in these ores, I was surprised to see a lot of grains of pyrite unusual shape, similar to the shot or buckshot. It was possible to see how the typical pyrite crystals in the form of cubes gradually turned into balls. Geologists believe that there is a process of dissolution or melting. It was a mistake: pyrite does not melt, and the dissolution arise very different forms. Microscopic studies of zoning of pyrite showed that the cause of these strange forms was … the process okatyvaniya! It was also possible to see the layered and cross-bedded, as in normal river sediments, sand accumulations pyrite with quartz pebbles. It was a completely unknown before the process okatyvaniya host rocks and earlier quartz-pyrite veins in the mineralized underground rivers.
So, in the depths of the volcano bubbling boiling water stream, and in it flew andesite boulders, crushed earlier ore veins as they milled iron balls ball mills for ore processing factories. Gases and water vapor mixture at a pressure of thousands of atmospheres in the lava broke through the vertical pipes and filled them with rounded fragments of minerals, ore veins and cemented their gold-bearing quartz. This picture is not painted before or monographs or books on geology. Ore deposits in the mountains of Kurama showed that conglomerate — cemented gravel — there is not only on the surface of the Earth — in the rivers and lakes, but also in its depths, the cracks filled with ore-forming fluid solution.
And most importantly: ore conglomerates Central Asia outward appearance is not different from … gold-bearing conglomerates of South Africa. You would have thought that the pyrite pebbles taken from one field, not having at opposite ends of the Earth. And their cement was geochemically similar: in addition to gold, it concentrated uranium and thorium. Hence, it is not necessary to connect the origin of gold-bearing conglomerates of South Africa, with deposits of ancient rivers: the riddle of the Witwatersrand is easily explained by the hypothesis of the origin of their depth by the energy of fluids — gases produced by magmatic melts.
Main mystery — the source of gold. Placers — secondary and primary gold brought from the depths of the Earth hot saline solutions, due to the huge mass of molten magma. In my opinion, the Witwatersrand gold associated with the introduction into the crust vast array Bushveld magma, whose area of about 200,000 square meters. km, and volume — more than a million cubic kilometers!
Ore banks surrounding the array and go deeper — to its "roots", so ore field is similar to the white mushroom cap upside down: a thick stipe — Bushveld is an array, and a hat — ore deposits. During the cooling of molten magma given much water vapor, which carried with it the uranium and put it in the quartz-pyrite veins of the surrounding sedimentary rocks. But then a catastrophic breakthrough gold-rich gas-saturated solutions, shattering the early ore veins and turn them seething energy flows in the reservoir underground conglomerates outwardly indistinguishable from the river. In this case, gold and uranium found in the cement between the pebbles of quartz and pyrite. The lack of oxygen protecting against oxidation unstable minerals pyrite and uraninite.
The hypothesis of the formation of deep mineralized conglomerates helped solve "unsolvable" geological puzzle. As the age of the array Bushvelskogo about two billion years, it almost coincides with the age of the ore beds. This means that the ore banks have been introduced into a thick sequence of sedimentary rocks at the same time, the allocation of a large "pot" of molten magma water-gas ore solutions. Stormy underground rivers flowed for thousands of years, as evidenced by the beautiful roundness of boulders of granite, vein quartz pebbles, grains of uraninite, pyrite and other minerals.
Enigma associated with abnormal accumulation of radiogenic isotope of lead — Pb-206, was able to explain the study of pyrite and quartz pebbles from Central Asia by electron paramagnetic resonance and Mossbauer effect. It turned out that the underlying weathered minerals preserve the memory of them received a huge dose of alpha radiation. In contrast, late quartz and pyrite in cement conglomerate, although they contain high concentrations of uranium and thorium were dose is 100-200 times less. What radioactive element could so strongly irradiated pebbles in a boiling solution? ..
As is known, the strongest alpha emitter is radon. However, radon is concentrated in the gas phase and the boiling solution is it can give a high dose of radiation at a relatively low content of uranium and thorium. Apparently, the underground rivers of Central Asia were literally full of radon. But radon short-lived and soon goes to the radiogenic isotope of lead — Pb-206, and the conversion of natural gas into the lead settles on fragments of rocks in the form of a thin gray film that easily dissolve ore solutions and deposited in the form of hydrogen sulfide, lead sulfide — a mineral galena. But in this case, galena dramatically enriched radiogenic isotope of lead geologist and therefore it will seem much older than the age of the true.
Let us remember that it was faced with this paradox geologists Witwatersrand: geologically young galena of cutting later lived had an incredibly "ancient" Archean age is due to the high concentration of radiogenic Pb-206. But the accumulation of Pb-206 is easily explained by the abundance of radon in boiling underground rivers that with an abundance of natural uranium, radon is constantly secreting. Subsequently diffused radiogenic lead concentrated in the later veins intersected ore deposits.
The idea of the possibility of the formation of the deep conglomerate that is very similar to the surface, thus relieving many mysteries and paradoxes. The presence of deep gold clusters in relatively young Paleozoic volcanic rocks can also give a completely new recommendations for finding gold giants. After all, before the geologists were convinced that they must be sought only in river sediments of ancient Archean rocks, the area distribution of which on Earth is small. You do not pay attention to the active role of magmatic rocks: they were like innocent.
In fact, the underlying ore-bearing conglomerates are formed in close connection with magmatism around a huge pool of liquid deep melt frosting in sedimentary and volcanic rocks, and their age may be relatively young, of course, by geological standards. Although this view was first suggested by me back in 1979-1980 gg, geologists, and now continues to rewrite the textbook to textbook accounts of the "mystery of river beds of the Witwatersrand."
It is difficult to calculate how many "friendly" reviews I had to get from the learned friend of the editors of scientific journals. "You were not in South Africa, and therefore you should not deal with such problems," — wrote in his review of Academician VI Smirnov, the largest and well-respected expert on ore deposits. Academician AA Shcheglov, being the head of the Far Eastern Scientific Center, listened to my report on the subject in Vladivostok. Then he went to the fields of the Witwatersrand. After returning from South Africa, he called me in Moscow and said he now fully shares my views. But when I asked for an article in the "Reports" RAS, he demanded to change it so that the meaning of the hypothesis disappeared. Other reviewers have responded simply: "The author's opinion is absurd, because it contradicts the scientific doctrine of ore deposits of gold and uranium …" Well, and so on.
Publish articles on this subject I found it extremely difficult. However, I believe that the inertia of thinking in the end will change and geologists understand that conglomerates with zolotouranovym hypogene mineralization are, t.e.imeyut deep origin. Now a number of prominent geologists shares the view of the depth of the Witwatersrand conglomerates. Among them Academician NA Shilo, Professor AA Kremenetsky known Siberian geologist SP Dolgushin, geologists from the Komi Republic and others.
Since hypogene conglomerates arose not only in ancient times the life of our planet, they can look at a much younger rocks around large granitoid massifs in the volcanic strata. For geologists search engines, this means that the area of promising areas increase dramatically: deep gold-bearing conglomerates of uranium can be found in relatively young rocks. It is possible that they may be related, and other minerals.
In the search for the underlying mineralized conglomerates have to remember that the most important feature that allows you to reliably distinguish them from the beach deposits of ancient seas, lakes and river courses, is the presence of rounded minerals that are unstable on the surface of the Earth. Of these, the most notable and popular — the same pebble pyrite, which has forced farmers Walker over a century ago to take up a basin to wash the quartz-pyrite-depth conglomerates of South Africa.
Doctor of Geological and Mineralogical Sciences