The city built by bacteria originated about three million years ago, and the process of its creation took from several hundred to thousands of years, which is not long in terms of geology, but still much longer than the time during which people build their cities.
Scientists measured the content of oxygen, carbon, and also isotopes of strontium in “remnants of buildings” to find out from what and when they were created. As it turned out, all the structures found are evidence of the vital activity of sulfate-reducing bacteria (this group of organisms includes both the bacteria themselves and the archaea, united by the method of energy production). They inhabit bottom sediments. Their activities have changed the chemical composition of the soil, creating favorable conditions for the formation of a manganese-rich mineral dolomite from the carbonate class. Dolomite deposits at the bottom and formed structures that resemble a cobbled street. Also, bacteria are able to create mineral formations that are wheel-shaped. They in the photos looked like the bases of ancient columns.