Can I find out where the gold ore lies

Can we theoretically calculate in which areas gold ore is deposited, determine the amount of its reserves in a particular field to decide whether it is profitable to build a mining enterprise here? After all, exploration and drilling of deep wells and exploratory mines take years and not one thousand dollars. Are there any signs on which the presence of a precious metal in the thickness of the earth's interior is guessed? Alas, mankind has not yet invented a single universal "recipe" for the search for gold deposits. Although long thought about this issue.

Gold ore requires a geologist to intuition, influx, almost art. In one locality, nuggets and dendrites almost sparkle underfoot, while in the other there are all the attendant signs, and in the rock there is no trace of precious metals. Understand the question of the emergence of this desired substance for people allows study of the processes occurring in the depths of our planet at a depth of several tens of kilometers.

The magmatic activity of the Earth drives through microcracks and large faults in rock formations hot solutions that leave a deposit of feldspars, quartz, sulfur compounds with various metals on the walls of these stone canals. Gold ore, platinum and silver can also be among them. Nuggets often have silver impurities. If white metal is more than 25%, such a stone is called electrum. There is also native silver, which contains an admixture of gold. These are custelites, where the yellow metal can be up to 10%. The study of the chemical composition of the solution, which 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 a sulfide and chloride medium.

But this knowledge does not bring us nearer to the practical result: the search for a gold deposit in a theoretical way. Chloride and sulphide sources are numerous, but the desired metal is not found in any of them. It can be assumed that the matter of interest to us was formed from the sediments of ancient alluvial seas buried under the many kilometers of earth. There, under the influence of high temperatures and pressure, it was melted into liquid magma, passed through cracks and faults, solidified in the form of ore or nuggets. But 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 satellites are other precious metals - silver, platinum, palladium, iridium, ruthenium, osmium and rhodium. Also, in a close intergrowth with inclusions of gold, less noble rocks are encountered: quartz, argentite, pyrite, galena, adularia, albite, amethyst. But the trouble is that these satellites most often do not have a single golden grain, and therefore can not serve as a guide in the search for the cherished veins.

Gold mining in Russia for a long time was made in placer deposits, that is, where it was washed into the surface by streams. And when in other countries invented new search tools and development technologies, we had troughs and sieves with tools of the gold prospector. The good thing is that there are a lot of these deposits in our areas. When they were exhausted in the Urals, huge deposits of placers were discovered in Siberia and the Far East.