Researchers have found native gold, silver and platinum salts in the dust of decayed stumps. A ton of their ashes contains 3 kilograms of silver, nearly 200 milligrams of gold and 5 grams of platinum.

These biogeochemical anomalies in complex ore deposit regions were formed by microbes and trees, which act as "gold-diggers" and draw soluble salts out of the soil and then die off, leaving behind the concentrate with enormous precious metals content.

The oxidation zone of some ore bodies is very close to the ground surface, within reach of tree roots. That is why, the researchers believe, the soil contains almost as much noble elements as the ore does. For centuries, trees and microorganisms gradually sucked them out of the depths and laid them in the soil. A living substance decayed, washed out and turned into carbonic acid gas, but metals remained intact.

The researchers investigated mineralogical composition of protore and oxidized ores from the Dovatka and Mykert-Sanjeevsky deposits. It has turned out that native gold, silver and minerals, which include platinum, palladium, iridium, rhodium and ruthenium, are contained in the extinct bacteria capsules.

The mineralogical composition of particles of bacterial origin turned out to be almost identical in the dust, soil and oxidized ores. Consequently, biomass of the trees, (reformed by bacteria), growing above the ore bodies’ oxidation zones is as if their natural continuation or their overground part.

There is peculiar division of labor among bacteria in the course of soil enrichment by precious metals. Sulfur-oxidizing bacteria leach minerals, i.e., transfer minerals from not readily soluble forms into labile forms, and iron bacteria glue them into new granules or nuggets. Trees assimilate the most readily soluble substances, which are later found in the cells of organolytic microbes feeding on dead timber. The latter also ensures normal vital functions of the first two groups.

Source: Geological Institute, Siberian Branch, Russian Academy of Sciences, Ulan-Ude