Reporter DAVID MACKIE discovers the reason why this year’s hot weather is revealing long-lost secrets of the land beneath our feet

AS the July sun beat down, and week after week drifted by without rain, the land began to reveal long-lost secrets. Ghostly outlines of millennia-old structures began to appear amid the yellowing grass and expanses of arable crops in the Vale of Pickering.

From ground-level, these shapes were almost impossible to identify. But from high above, they grew ever more pronounced as the drought wore on.

In the heat of the summer, local archaeologist Professor Dominic Powlesland, of Yedingham, set about documenting these ancient shapes, photographing them from a small aeroplane, or flying a tiny drone over the land to get a bird’s eye view.

They are everywhere, he said: across the vale, up onto the moors, down over the wolds.

Evidence of communities of peoples living and shaping this area over thousands of years.

The shapes appear every summer, and Professor Powlesland has been documenting them for 40 years. But this year has been special.

“This year’s drought is very unusual,” he said. “I’ve been doing this a very long time. This year, particular types of features are showing on a scale that I wouldn’t normally expect.

“Primarily Iron Age square barrows. They date from about 450BC to 200BC. The ditches around them are really quite small so often they don’t produce a crop mark, but this year they’re all over the place.”

Barrows are burial sites, and nothing seems to show up on the surface quite like the sites where our ancestors laid their dead to rest. The land below us is peppered with them.

They are so common because this area has been a working landscape for so long. Professor Powlesland describes a highly-populated ancient landscape, arranged along what is now the A64, next to what was once wet marshlands.

“The work we’ve done in Heslerton, including vast acreages of excavation, has revealed a landscape that was infinitely fuller in the past than we ever could have thought,” he said.

“There’s activity from the late palaeolithic. So that’s from 15,000BC through to the present.

“We now know it was very, very densely populated, from the neolithic (3,000 BC) onwards. It’s heaving with people. They cut down most of the trees in the valley.

“By the middle of the Bronze Age, so by 1500BC, this is a managed landscape. It’s connected with routeways and trackways that go all over the place.

“By the middle of the Iron Age there’s an enormous population, and we had things called ‘ladder settlements’ which were a bit like linear cities. They’re trackways with farmsteads on either side which are using the whole landscape.”

The concept of Ryedale being such a populated and developed area hasn’t always been so well understood.

“When we came here in 1978, it was suggested that the Vale of Pickering had almost no archaeology at all,” he said. “The reality is it’s probably no different from any other valley system in Britain.”

But it is much better understood now because of the sheer quantity of work and analysis done on the area.

Professor Powlesland, 63, runs the Landscape Research Centre, a charity which he founded in 1980. Since then, this area has been the site of the largest geophysical survey in the world.

“Geophysical surveying means looking at the ground without digging,” he said.

“We use magnetic gradiometry - which is where you’re looking at the variable ground magnetism.

“So an archaeological feature which has been disturbed and has burnt material in it or lots of organics has a different magnetic signature to the undisturbed soil next to it.”

The other tool they use for surveying is aerial photography.

Aeroplane photography - and more recently drone photography - has been key to mapping the various archaeological features in the Vale of Pickering. When he was a teenager, growing up in East Anglia, his dad enjoyed flying and so Dominic would join him.

“I saw these amazing features in the landscape and realised there is a whole story that emerges every year in the fields,” he said.

“I’ve been particularly interested in that since I came here.

“We started a programme of aerial photography pretty much straight away, all of which was unfunded. I had to rely on generosity of local pilots to take me flying. Fortunately we’ve always found people willing to do it - and as a result we’re able to to record crop marks primarily covering the area from the middle of the Vale of Pickering south to the Great Wold Valley.”

He’s seen some changes over that time. Weather conditions and changing farming practises alter what marks are shown up by the land.

“During the 1980s and into the 1990s we had a gradually increasing body of crop mark evidence,” he said. “And then there was a fall off. But since 2003 or 2004 there’s been another rise in the number of crop marks we’ve seen that are new.

“This represents changes in agriculture more than anything else. The crops have changed and the depth of ploughing has changed - even a change of half an inch makes a huge difference.”

But how and why do crop marks show?

Their formation is fairly simple in principle, Professor Powlesland says.

In essence, structures lying under the earth - depending on what they are - either increase the amount of water and organic matter available to plants on the surface, making them grow better, or in some cases, restrict their growth, leading to ‘parching’ of plants where they die quicker than those around them.

This area has seen some major discoveries.

A Roman villa lies underneath the ground near Hovingham.

Professor Powlesland says that Star Carr, near Flixton at the eastern end of the vale, is “probably the most important early mesolithic site in northern Europe.”

And the outline of the village of Wharram Percy can be seen from the air in some of Professor Powlesland’s pictures.

Last year, researchers from the University of Southampton revealed that some medieval villagers buried in the graves there between the 11th and 14th centuries had been burnt, dismembered and decapitated.

The researchers’ theory was that these mutilations were carried out by villagers who believed that it would stop the corpses arising from their graves and “menacing the living”.

Professor Powlesland is careful not to reveal the exact locations of archaeological features, in case they’re exploited by illicit treasure hunters.

In his home office, we look through just some of thousands of images he has taken this summer.

The signs are all there in the fields of barley or sugar beet. Iron Age square barrows, Bronze Age circular barrows, the dark spots of countless graves, the grid-like outlines of long-houses, long lines delineating grave sites from the rest of the ancient community.

It’s clear the ground below our feet contains many more secrets to discover.