Exploration

Sunken Lost City? Not Really

Initially thought to be the remains of a long-lost city, new research finds the underwater features were actually made by geologic processes.

<p>Credit: University of East Anglia </p>

Greek underwater features that look like ancient paved floors, courtyards and colonnades do not belong to some sort of Atlantis-like city, but are the product of a natural geological phenomenon that occurred up to five million years ago, says a new research into a site off the Ionian island of Zakynthos.

Discovered by snorkelers and divers near Alikanas Bay, the structures bear a resemblance to archaeological stonework of the Hellenic period, such as circular column bases, pipe-like formations, and doughnut-shaped arrangements. Initially it was believed they were the remains of a long-lost civilization that perished when tidal waves hit the shores of the Greek island of Zakynthos.

But all that glistens is not gold.

RELATED: Small 'Underwater Pompeii' Found Off Greek Island

A joint research from the University of East Anglia (UK) and the University of Athens (Greece), published in the journal Marine and Petroleum Geology, has shown the "long-lost Greek city" in fact consists of fossil features possibly of Pliocene age.

"We investigated the site, which is between two and five meters under water," lead author Julian Andrews, from UEA's School of Environmental Sciences, said.

WATCH: Can We Save Our Cities From Drowning?

"Mysteriously, there was no other signs of life, such as pottery," he added.

Using microscopy, X-ray and stable isotope techniques, Andrews and colleagues analyzed the mineral content and texture of the underwater formation.

"The disk and doughnut morphology, which looked a bit like circular column bases, is typical of mineralization at hydrocarbon seeps - seen both in modern seafloor and palaeo settings," Andrews said.

RELATED: Wreck Yields Treasures of Ancient Greece's '1 Percent'

The researchers speculate the distribution of such doughnut shaped concretions is likely the result of a sub-surface fault which has not fully ruptured the surface of the sea bed.

The fault allowed gases, particularly methane, to escape from depth.

"Microbes in the sediment use the carbon in methane as fuel. Microbe-driven oxidation of the methane then changes the chemistry of the sediment forming a kind of natural cement, known to geologists as concretion," Andrews said.

He noted that in this case the cement was dolomite, an unusual mineral which rarely forms in shallow seawater, but can be quite common in microbe-rich sediments.

"It is important to look carefully at underwater stonework in archaeological settings like Greece or Italy and be very sure that we look for all the evidence to prove that the archaeology is really what we think it is," Andrews told Discovery News.