What was thought to be ancient underwater remains of a lost city has turned out to be simple geological formations, a new study has shown.
New research from the University of East Anglia and the University of Athens have found that what was thought to be sunken city 20 feet under water near the Greek isle of Zakynthos are actually formations built by bacteria.
Divers discovered what looked like an ancient toilet and what appeared to be sunken cobblestones and symmetrical stone cylinders, but found no signs of life ever having existed around these formations. Evidence of human life having existed would have included the presence of pottery or coins.
A study published June 2 in “Marine and Petroleum Geology” analyzed the mineral content of the structures and found that the formations contained a mineral called dolomite, a calcium byproduct produced by microbes that feed off methane.
According to the study, the structures were created in the Pliocene era up to 5 million years ago.
“Essentially what you’ve got are bacteria that are fossilizing the plumbing system,” study co-author Julian Andrews of the University of East Anglia told Smithsonian Magazine.
As gas seeped in through subsurface faults, bacteria gathered around the source and their calcium excrement reacted with the methane to produce a cement-like substance.
The tubular structures were likely formed as microbes piled up around focused jets of methane, and the slabs that built the city's "streets" may have been the result of large, sloppy spews of gas.
While no gas leaks in the area today, the phenomenon isn’t uncommon. It usually occurs at deeper depths.
