In the Mud

Nine o’clock on a winter morning. I crunched my way through sand-dunes hardened and sheened with frost, then slithered over a sheet of ice. Under the ice, pale bubbles swelled and skittered away from my tread. The tideline was a sparkling white ribbon of frozen froth, curling away into the distance. I stopped to watch oystercatchers pecking at a frozen pool. I visited a shipwreck, its timbers rimed with frost, then walked on, trying to work up some warmth.

After a couple of miles, I spotted a large expanse of broken ground, darker than the surrounding sand. The tide was very low, and the broken area well down the beach. It was an area perhaps 50 metres by 30: complex and layered, startlingly different from the smoothness of the rest of the beach. A series of miniature cliffs, islands and peninsulas, all made of dark brown stuff like clay, were moated around by channels and pools of icy water which the sea had left behind. This strange and incongruous sight was a piece of the distant past. The muddy outcrops offer an opportunity to visit a piece of a world lost thousands of years ago, before ‘history’ began. But it’s a fleeting opportunity, before the tide comes in and erases it for ever.

I’ve been walking on the shore at Ainsdale and Formby, on the north-west coast of England, for 20 years. It’s hardly the prettiest or the most unspoilt beach: its sands are not the most golden, and there are no rockpools or hidden coves. It’s not dramatic either: no pounding surf or rugged cliffs. Stand here, on a reasonably bright day, and you can see the offshore wind farm in the Mersey estuary. Turn the other way, and there are the familiar Blackpool landmarks: the tower, the rollercoaster. But in really clear weather you can see the southern fells, the Clwydian hills, the pale but unmistakable shape of Snowdon.

Beaches are places where discoveries can be made, from a creature wriggling on the wet sand to miscellaneous lost and abandoned human possessions. But what I was looking at was not cast up randomly on the tide. In the 1950s people began to notice that hoofprints were appearing from time to time in sun-hardened outcrops of mud along the foreshore. But their significance was not understood until 1989, when a local man called Gordon Roberts began walking his daughter’s dog and observing them for himself. Most of us would have walked on without a second thought. There’s no shortage of footprints on the beach: from people, dogs, horses and birds. But Roberts, who had a longstanding interest in archaeology, realised that these prints were likely to be very old. He began to make calls to universities and museums, and to study the marks himself and make a photographic record.

To begin with, it was thought that the prints might belong to domesticated cattle kept by Iron Age people. There is a theory that a sub-tribe of the Brigantes called the Setantii settled this coast, all the way from the Mersey to Borrow Beck in Cumbria. Cattle footprints would have been an exciting piece of evidence in support of the theory. But this notion came to seem less and less convincing. Gordon returned again and again to the site, observing variations, depending on weather and tidal conditions: one day nothing would be visible, and the next he would find more and different prints. Birds and animals of various kinds, and human prints. Plaster casts were taken, allowing the prints to be studied in detail, and they didn’t seem consistent with the evidence we possess about Iron Age life. Iron Age people were farmers rather than hunters: they kept cattle, sheep, oxen and pigs. The footprints were from quite a different range of species, including roe deer, red deer and wild boar.

Some samples of the silt in which the prints were found were carbon dated and subjected to a process known as optically stimulated luminescence, which can determine how long ago sediment was last exposed to daylight by measuring the radiation in the minerals it contains. These methods gave dates from the late Mesolithic (7000 BC) to the mid-Neolithic (3000 BC). Neolithic innovations included farming and herding, but in places like this which were unsuitable for agriculture, people went on living by hunting, gathering and fishing. The wild boar and deer would have provided food for these communities, and the human footprints are those of the hunter-gatherers who relied on them.

The prints have survived because they are preserved in layers of sediment until recently hidden under the surface of the sand. This sediment is what remains of the reed-fringed lagoon and mudflats which once occupied the area. The coastline has always gone through periods of change, as the sea advances and retreats. During one such period, the sea level fell and the coastline moved west, covering over and sealing in the mudflats. For three and a half thousand years the sediment lay buried beneath the land. In the early 20th century, another period of change began, as the coastal dunes were eroded. The prehistoric mud, until relatively recently covered by these sand dunes, now lies under the beach instead. It’s very shallowly buried, sometimes only about six inches under the surface of the upper foreshore, and is easily exposed.

In periods of relative calm, deep runnels cut down through the sand, exposing sections of the ancient sediment below. The sediment is very dark, almost black, and completely different in texture to the sand around it. When the wave energy is low, you can see it swirling about at the edge of the sea and streaking the sand with black dust. Sometimes people think it’s oil. If you run barefoot towards the sea, you can find yourself slipping on a patch of black mud which oozes up from under the sand. It’s prehistory, stirred up, carried to the surface and coating your feet.

The remnant of the ancient mud lagoon I’d stumbled across was much more extensive than the fragments I’d seen before, deep, and made up of many strata. If you broke off a piece, you could peel the layers apart; they were as flexible as rubber. Within each stratum were countless micro-strata, each one representing a twice daily silt-laden tidal incursion over a period of two and a half thousand years. I was at one of the four main sites in an area known as Mad Wharf. Human and animal prints emerge at all four, according to a largely unpredictable timetable of weather and longshore currents. The heyday was the mid to late 1990s; as the sea continues to move inland it has covered much of the former lagoon. Fewer and fewer prints are being exposed, and no one knows how far inland they reach, and how many remain to be discovered.

Alone on my island of prehistoric mud, I found my first human footprint. It was perfectly defined, deeply indented where the foot had sunk into the soft mud, and lined with tiny shells. And now my eye was accustomed, I could see dozens more, developing before my eyes like photographs in a darkroom. Sometimes there was just a vaguely foot-like shape I identified by squinting and looking from different angles; others were as clear as if they had been made yesterday. But there was something much more exciting: a distinct trail of imprints, emerging from underneath one of the layers and leading out towards the sea. Trails like this are valuable evidence. Some of the prints were filled with water; one still had a skin of ice which wrinkled when I touched it with a fingertip.

I was almost certainly the last, as well as the first, to see this evidence. When the next tide covered them, they disappeared without a trace. For every print revealed to us there are others which will for ever lie under the sand; and the prints themselves represent just a fraction of the steps made in the first place. For prints to persist, certain conditions were required. First, the sediment had to be soft and muddy enough for an indentation to be made and to remain after the foot was removed. The mud must have been very soft in certain places and at certain times: some of the prints are several centimetres deep. Next, the print would have been covered by very fine, light, windblown sand. The weather had to be warm and fine, allowing the imprinted sediment to dry out sufficiently before the next tide came in and covered it. Finally, the tide itself needed to be gentle and with very little wave action, so that the surface was not disturbed but delicately sealed with silt and clay.

Alongside the slow cycle of coastal accretion and erosion, seasonal patterns and daily changes in weather conditions keep things unpredictable. You can find a particularly significant set of prints, and mark them with plastic sticks, intending to return, only to be thwarted by wind blowing sand over the site, or heavy rain damaging the prints. Or they can be degraded or polluted by vehicles and horses crossing the mud. These frustrations are an inescapable part of what Roberts calls ‘ephemeral archaeology’.

Another animal that left its mark here was the aurochs. In Britain this mighty creature, a species of wild cattle, had been hunted into extinction by the end of the Bronze Age. It was a real monster, standing two metres high at the shoulder and weighing about a thousand kilograms. Julius Caesar wrote about it in The Gallic Wars, describing it as ‘a little below the elephant in size, and of the appearance, colour and shape of a bull’. Because it has been extinct for hundreds of years, the prints found here are prized for the information they offer about the animal’s habits, its physical characteristics, even the way it walked as it grazed on the dune grasses and wallowed in the mud. There is skeletal evidence elsewhere: the skull of the last surviving aurochs is in a museum in Stockholm, and remains have been excavated in Peterborough. But much of the information about this beast comes from a strange and unexpected source: the Paleolithic cave paintings at Lascaux. Indeed, the detailed depiction of a hoofprint on one of the paintings helped confirm the identification of the tracks on Formby beach. There is something miraculous about the ability of 17,000-year-old paintings to help in scientific discovery today. They tell detailed stories about a part of our past which would otherwise be unreadable.

Perhaps we have the wrong idea about beaches. Golden sands are pretty, but mud is full of treasure. Ancient pollen grains tell us what grew here. Traces of charcoal suggest campfires and settlement. The footprints have yielded sufficiently detailed information not just to give a general idea about life in Neolithic times, but to give us an idea of the individuals who made them. Gender is relatively easy to distinguish, because men’s and women’s feet are surprisingly different: not only do men’s tend to be longer and broader, but a woman’s foot has a higher arch, a shallower first toe, a smaller ball of foot circumference and a smaller instep. With expertise, it’s possible to estimate stature, stride and speed. Evidence of an unusual gait can suggest that one woman was very pregnant, or that another was suffering from bursitis or a foot deformity characteristic of diabetes or muscular dystrophy. We are given a glimpse of the actual people who walked here, where I walk today. Sherds of pottery, fragments of cloth, even drawings are telling, but secondary. Where a human being has placed a hand or a foot, and made a mark, there’s a shortcut of recognition.

Like Crusoe, I’ve found proof that I’m not alone. It’s not just space we share, but time too. When I unlace my boots and step barefoot onto the freezing mud, I experience a tangible sense of connection with the past. Seven thousand winters have passed since these footprints were laid down, preserved and buried. There was no wheel, and no writing yet. Stonehenge was still a couple of thousand years off. But in Mesopotamia, wheat and flax were being farmed; fine glazed pottery with stylised figures of animals and birds was being made; and the hilltop temple complex at Göbekli Tepe was already five thousand years old. For a second I see that five thousand years is not some abstract concept, but simple and actual and not unimaginably long. And now these marks have come to the surface again: the marks my analogues made, as they gathered shellfish and hunted for food, and those made by their children as they ran about and played in the mud. I can trace a footprint with my fingers, put my own bare foot inside it. It’s the nearest I can get to time travel.