ONE of the best known natural features of northern England is four times older than previously thought, a cave diving scientist has claimed.

Phillip Murphy dived under the huge wall of Malham Cove, in the Yorkshire Dales National Park, to find stalactite samples proving the structure must be at least 50,000 years old.

Scientists had believed the 250ft limestone cove, which forms one of the most popular picture postcard images of Yorkshire, was formed during the last glaciation, which ended 14,000 years ago.

But Mr Murphy, an earth sciences technician at Leeds University, said: "As one of the few cave-diving earth scientists in the UK, I can reach otherwise inaccessible areas.

"I heard that a fellow diver had come across a speleoth-em, as stalactites and stalagmites are collectively known, in an underwater cave.

"Speleothems don't form during glacial periods, as freezing temperatures mean there is no moving water.

"So the speleothem discovered in the Malham cave system must have been formed during a warm period between the glaciation which formed the cove and another which deposited the silt.

"When the ice melted, the silt then caused the caves to flood."

Mr Murphy said University of Liverpool archaeologist Alf Latham dated the speleothem at 26,000 years old.

He said this proves the cave system was re-flooded after the last ice age, about 20,000 years ago, and that the initial formation of Malham Cove must have taken place more than 50,000 years ago.

Malham Cove is a 250ft sheer cliff, more than 1,000ft wide. It was formed by glaciers and waterfalls and the area around it covers a network of cave systems created by water dissolving the rock.