Can we theoretically calculate in which areas gold ore is deposited, determine the amount of its reserves in a particular deposit, in order to decide whether it is profitable to build a mining enterprise here? After all, exploration, drilling of deep wells and exploration mines takes years and more than one thousand dollars. Are there any signs by which the presence of precious metal in the depths of the earth's interior is guessed? Alas, mankind has not yet invented a single universal “recipe” for searching for gold deposits. Although this question has long been thought about.
Gold ore requires intuition, intuition, almost art from a geologist. In one area, nuggets and dendrites almost sparkle underfoot, while in another there are all the accompanying signs, and there is not a trace of precious metals in the rock. To understand the issue of the emergence of this desirable substance for people allows the study of the processes occurring in the bowels of our planet at a depthseveral tens of kilometers.
The magmatic activity of the Earth drives hot solutions along microcracks and large fractures in rocks, which leave deposits of feldspars, quartz, sulfur compounds with various metals on the walls of these stone channels. Gold ore, platinum and silver can also be among them. Nuggets often have silver impurities. If the white metal is more than 25%, such a pebble is called electrum. There is also native silver, which contains an admixture of gold. These are kustelites, where the yellow metal can be up to 10%. The study of the chemical composition of the solution that brought precious metals from the lower layers of the earth's crust to a depth of 5-7 kilometers to several tens of meters shows that they must be sought in sulfide and chloride environments.
But this knowledge does not bring us any closer to the practical result: the search for a gold deposit in a theoretical way. There are many chloride and sulfide sources, but not all of them contain the desired metal. It can be assumed that the substance of interest to us was formed from the sediments of ancient alluvial seas buried under many kilometers of earth. There, under the influence of high temperatures and pressure, it was melted into liquid magma, passed through cracks and faults, and solidified in the form of ore or nuggets. But even this scientific hypothesis does not yet give us practical benefit.
Let's try to go the other way: to determine the list of minerals with which gold ore most often coexists. Its companions are other precious metals - silver, platinum, palladium, iridium, ruthenium, osmium and rhodium. Also, less noble rocks are found in close intergrowth with gold inclusions: quartz, argentite, pyrite, galena, adularia, albite, amethyst. But the trouble is that these satellites most often do not have a single grain of gold, and therefore cannot serve as a guide for us in the search for the treasured vein.
Gold mining in Russia for a long time was carried out in alluvial deposits, that is, where it was washed to the surface by streams. And when in other countries they invented new search tools and development technologies, we still had troughs and sieves as tools of a gold digger. Fortunately, there are still a lot of these deposits in our open spaces. When they were depleted in the Urals, huge accumulations of placers were discovered in Siberia and the Far East.
