WHEN the days are shortest and the nights come earliest, the bare, bleak, wide expanses of plough and fallow field come into their own. It’s only when the crops are taken and the ground is tilled that these lands reveal their oldest secrets. 

At this time of year we tend to “field walk” until the dusk comes on, and only then to find a bit of bank or a log where we can sit and picnic.

This time, we weren’t ready after our picnic for our return walk until full darkness had come. We got our torches out and started to trudge back across the sticky gault clay fields. Wanting to snatch a bit more searching time, I trailed a bit behind Jane and swept the earth with my torch as I walked. 

And there it was. 

A muddy, oval, “worked” chunk of flint about five inches long by three-and-a-half inches wide. Worn white by the weathering of millennia, but unmistakeable. An ovate hand-axe made by the ancient people. When I took it afterwards to Matthew Pope, our local expert on the flint peoples, he told me the axe was late Neanderthal, and was maybe a training piece made by some youngster (because it was made on poorer-quality flint). Somewhere between 60,000 and 30,000 years old, it was made not long before the Neanderthal people disappeared. Back then that ploughed field was at the edge of a wide marshy vale, which would have teemed with wildfowl, fish, pig and deer. 

Two winters ago while walking across one wide ridge-top ploughland I started to spot flint “flakes” — the discarded debris of a prehistoric tool-making spot. We stopped. I said to my 15-year-old grandson Che: “This spot looks good … I’ll give you a couple of quid for every tool you find!” 

He looked at his feet, hesitated, stooped, picked up a flint and passed it over. “How about this!” It was a flint “scraper,” a multipurpose tool used for cleaning skins and roots, stripping canes, and all sorts. He took a couple of steps forward, stooped and picked up another flint. It was a mini hand-axe with notched edges. He took a couple more steps further, stooped and picked up a third flint. Another scraper. Then he walked a couple more paces and stooped again. Yet another scraper…

A good thing I didn’t offer him a fiver a tool. He’d have cleared me out!

There are vastly more ancient things to be found on your field walkings than those prehistoric stone tools. The soils of each geological area will have their own fossil assemblages. In areas over Jurassic formations (from Oxfordshire west and northwards) fossil belemnites and corals may be more obvious, and on Cambrian rocks there may be trilobite fragments. Only on volcanic rocks will there be no fossils, but their range of minerals and crystals will compensate for that. 

Each layer of our chalk country has its own characteristic fossils. The “shepherd’s crown,” echinocorys, sea urchins are common on our hilltops. Nearer the scarp of the Downs we find “fairy loaf,” micraster, sea urchins. You can still find old cottages with their “fairy loaves” arrayed along a window sill. 

On the big grey chalk fields below the edge of the Downs you can find many different species of ammonite. It can be as good as Lyme Regis. The type most people find first is a little “waggon wheel” ammonite called Schloenbachia varians. Sometimes you find big “tractor tyre” ammonites, too, a hand’s length and more wide, though the soft grey chalk means you have to be very careful to keep them intact. If you are also scrabbling in the redundant chalk quarries nearby you may end up with well over 20 species, plus fragments of smooth round nautiloids, pieces of clam and scallop, and other mussel and cockle-like Cretaceous bivalves and brachiopods, and fossil snail-like gastropods. 

There’s one fossil sponge that turns up on most fields around Brighton, and most back gardens, too. It’s called the “king’s sponge,” Siphonia koenigi, though it should be called the “tulip sponge” because it looked like a giant tulip on its long stalk anchored in the primal ooze at the bottom of those tropical seas. Sometimes it’s spectacularly well-preserved.

Every farmland district will have its own specialities. 

Walking a ploughed field edge by a stream on the Wealden Clay, I spotted a chunk of rounded flint like a broken piece of chocolate egg. Its interior was made up of clusters of semi-transparent red bobbles, like tiny grapes, or caviar. When I held it up to the sun it shone through with warm light. It now sits in pride of place near my front window, where the sunlight can catch it. Its full descriptive name is a bit of poetry I love reeling off … my tongue-twisting piece of “geodic carnelian botryoidal chalcedony”! (“Botryoidal” means “like a bunch of grapes”).

On these winter fields the flowers have either died back underground or survive as seeds, and only scattered rosettes of cranesbill and speedwell, and dead strands of corn spurrey and pimpernel hang on. 

If you hunker down and peer closely, though, you will find that the clans of tiny mosses and liverworts have come into their own. They can cover large areas of bare ground and their variety can equal the variety of summer flowers and grasses. If you have a x10 eye glass and a simple guide (try Ron Porley’s beautifully photographed Arable Bryophytes) you will readily find the spiky little tufts of crimson tuber thread moss, which holds its bright red tubers in the axils of its shoots and leaves. 

Many of these bare field mosses, like the earth mosses and pottia mosses, are extremely fruitful and are covered in weeny bead-like spore capsules, which help you identify them. 

With a bit more luck you’ll find the tiny little radially symmetrical rosettes of green crystalwort (Riccia spp), which do vaguely look like neatly arranged minuscule slices of green liver. If you find the crystalwort, you might well find frillwort, (Fossombronia spp), close by. These look exactly like centimetre-sized summer lettuces. Once you’ve found one, you’ll find it again and again.

Winter is the metal detectorists’ prime season, too, and they have their favourite spots, where the farmers have given them the OK. They tend to be a bit more dependent on farmers’ permission than us free walkers, because they have to hump their valuable equipment round, and therefore need to park nearby. They’re a friendly lot, and a good chat with them can beautifully complement the “picture” you can conjure of past historic and prehistoric activity. They’ll turn up coins and medieval trade tokens, buttons, clasps, bits of knife and tool and even jewellery, alongside the usual array of broken farm equipment and modern junk. Their focus will be on the historic, medieval, Roman and back through the Iron and Bronze Ages, whereas mine is on the long stone ages and geological past.

Detectorists’ activity has become vastly more difficult in recent years, since farmers have taken advantage on a large scale of local council greenwaste, recycled by waste processing firms as free agricultural grade compost.

It was around 15 years ago that we first started noticing farmers’ ploughed fields pixelated all over with bottle tops, mesh and wire, endless bits of coloured plastic bags, containers, cans and their ring-pulls, right through to bits of clothing.

On one field where I went to field walk for flint tools, I picked up two full Sainsbury’s bags of junk in about 20 minutes. At that point the farmer spotted me from her distant landrover and motored across the field to ask me my business. 

“You think you’re doing no harm,” she said, “but you’ll just encourage other people to trespass. You’ve no idea how much litter they can leave.” I didn’t show her my two Sainsbury’s bags.

That was the third year that farm had been spreading litter-laden greenwaste on that field. The distraction caused by those teeming thousands of little and not-so-little metal and flapping plastic fragments drained all the focus I could give my field walking, and would have made a detectorist’s task impossible. I’ve not been back there. 

Don’t ever take farmers’ and landowners’ whinging against litter-spreading townie visitors seriously. Farmers can be the worst litterers of all.

Greenwaste processors have got much better at removing gross items of litter from targeted farm composts in recent years, but even in the most recent greenwastes I have seen on farmers’ fields residual domestic detritus is still present. Given that these treatments are put on annually, the long-term damage to the integrity of local soils and archaeological and fossil assemblages is likely to keep increasing, despite these improvements. 

No more will we be finding the microliths of the bow-and-arrow hunters, or the barbed arrowheads of the Bronze Age farmers. It’s plastic litter that will be the heritage we pass on to our detectorist and field-walking grandchildren.

Notes From a Free Walker with Dave Bangs is a monthly column that appears on the second weekend of the month. Keep an eye out for the next one on March 10.