Mineralized microbial waste mistaken for ancient metropolis
If there’s one thing ancient Mediterranean cultures were known for, it’s columns, right? Nothing says “ancient Greece” like a some nice, Ionic colonnades around a big marble building. A statue of a god would really seal the deal, but most of us would start guessing ‘Greece’ or ‘Rome’ when presented with these architectural snippets, especially if we saw them off the Greek island of Zakynthos. And, as it turns out, most of us would be wrong.
While on vacation, snorkelers reported finding what appeared to be tiled floors dotted by structures that appeared to be the bases of a Doric-esque column. The concentric layers of these structures strongly suggested that a city had once stood at this location, just off the shore, and had perhaps been lost to the sea after some sort of geological catastrophe. When trained archaeologists arrived, they immediately noted that there was a lack mundane objects tied to human life, like pottery for holding water and food. While not every city is expected to be as well preserved as Pompeii, the fact that this entire “city” was now reduced to short, similar but imperfectly matched cylinders pointed to a very different explanation.
Made from methane and microbes
Samples of the columns were analyzed, confirming that these structures were built not by ancient Greeks, but by ancient microbes. Microbial life in the sediment fed on carbon in methane, and as a result clustered over places where methane concentrations were higher. In this case, an underground fault was slowly leaking the gas, and microbes gathered to feed in the fissures as the gas bubbled up. Microbial waste built up, and was then mineralized, only to be uncovered by erosion now appearing to be the bottom of a load bearing structure. The fact that the methane was escaping along a fault meant this collection of microbial columns was distributed roughly in a line, which must have further reinforced their resemblance to a grand Greek temple. So while the vacationing swimmers didn’t find an ancient city, hopefully they’re still proud of finding some very old, peculiar microbe-poop.
Source: Underwater 'lost city' found to be geological formation, Archaeology News Network