Geologists have discovered what they say is an ancient, lost landscape that lies deep beneath the sediment of the North Atlantic Ocean near the northern coast of Scotland.

The massive landscape with furrows cut by rivers and peaks that once belonged to mountains is believed to be some 56-million-year-old.

“It looks for the entire world like a map of a bit of a country onshore. It is like an ancient fossil landscape preserved two kilometres beneath the seabed,” senior study researcher Nicky White was quoted as saying by LiveScience.

The researchers, who used an advanced echo-sounding technique to find the landscape, said their data have so far revealed a landscape about 10,000 square km west of the Orkney-Shetland Islands that stretched above sea level by almost as much as 1km. They suspect it is part of a larger region that merged with what is now Scotland and may have extended toward Norway in a hot, pre-human world.

The researchers, who detailed their findings in the journal Nature Geoscience, used high-pressured air via metal cylinders, producing sound waves that travel to the ocean floor and beneath it, through layers of sediment.

Every time the sound waves encountered a change in the material, an echo bounced back and microphones trailing behind the ship on cables record these echoes. From the information, they constructed 3-D images of the sedimentary rock below, said White, a geologist at the University of Cambridge.

The team found a wrinkly layer 1.2 miles (2km) beneath the seafloor — evidence of the buried landscape, reminiscent of the mythical, lost Greek island Atlantis. They traced eight major rivers, and core samples, taken from the rock beneath the ocean floor, revealed pollen and coal, evidence of land-dwelling life.

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