Several years ago, snorkelers off the Greek island of Zakynthos were amazed to find what they though

Several years ago, snorkelers off the Greek island of Zakynthos were amazed to find what they thought were the remains of an ancient Greek civilization submerged in the shallow water. What appeared to be stone columns and column bases, so common to the Hellenic landscape, scattered the sea floor, giving the impression of ancient architecture taken over by the sea. However, a recent paper published in Marine and Petroleum Geology explains that the column-like structures are not stone at all, but were created by microbes in a process that breaks down methane gas! The methane moves up through faults in the Earth into the sediment that makes up the seabed. Here, bacteria in the sediment consume the methane and thus change the chemical makeup of the surrounding seawater. This causes dissolved minerals to precipitate out of the water and form a type of rock called dolomite, which cements the sediment and forms concretions. The concretions take the shape of columns and similar donut shapes because of the way the methane flows through the sentiment.While not unheard of, concretion structures are uncommon in such shallow waters. Similar phenomena have been seen frequently in the North Sea and in fracking sites. Julian Andrews, the head researcher, reported to CNN that “these gas leaks are quite common” and that “the earth’s crust is quite a leaky material.” Andrews continues to explain that the Zakynthos site is notable for its “shallow setting.” While the snorkeling tourists might be disappointed that they didn’t stumble across a real-life Atlantis, for those of us who love microbiology, this discovery is just as golden!To read more, check out the full article. -- source link

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