Mysterious ice pancakes on river

Biologist Jamie Urquhart found the strange ice pancakes near the River Dee in Scotland.

The theory is that the pancakes were formed when foam spinning in river eddies became frozen and was later softened in fluctuating temperatures.

It's the first time the ice pancakes have occurred on the Dee, but they're thought to be more common in Antarctica or the Baltic Sea.

The pancakes were found several miles downstream from Balmoral Castle, the British Queen's summer residence.

• Ice pancakes found by biologist near the River Dee in eastern Scotland


• The Trust believes the phenomenon is caused by foam freezing in river eddies


• Ice pancakes are said to be more common in he Antarctic or Baltic

London (CNN) -- Here's another Scottish mystery to file alongside the Loch Ness Monster and Mel Gibson's accent in "Braveheart."

Ice pancakes.

These strange frozen saucers were found during a recent cold snap near the River Dee -- a salmon-filled waterway that passes by the British Queen's summer residence, Balmoral Castle, before heading eastwards to the coastal city of Aberdeen.

River Dee Trust biologist Jamie Urquhart made the discovery and took the photos at Lummels Pool, Birse -- several miles downstream of Balmoral.

The trust said it was initially unsure what caused the pancakes, but supects they're caused by a rare phenomenon in which foam freezes in a swirling eddy.

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Rare occurrence

"Perhaps each disc grew when smaller pieces of unfrozen foam struck the disc, adhered and then froze in place," it wrote on its website.

"The raised rims are undoubtedly due to the collisions but what about the inner lines?

"The air temperature was colder at night due to the clear-sky conditions but warmer in the day, meaning the discs may have grown at night, then during the day, when the discs softened in the sun, further collisions between the 'pancakes' caused the rims to be pushed up.

"The next night further growth would have occurred, followed by a new rim the next day."

The Trust said it's the first time the pancakes, more commonly found in the Antarctic or the Baltic Sea, have been seen on the River Dee.