Seduced by Silver but sustained by lead

We begin quite a way up the South Tyne Valley – appropriately at a place called Tynehead to try to get to the bottom of the many stories about the Romans and silver mining in the north. The metals theme continues with stops and stories at a prehistoric barrow at Kirkhaugh and a Roman fort thought by some but not all to be positioned to protect Roman state lead mining. The episode ends beside the South Tyne at Beltingham -  which tells a different story about mining metals in the North Pennines.

Transcript

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Episode three Seduced by Silver but Sustained by Lead We begin quite a way up the South Tyne Valley, appropriately at a place called Tyne Head. We're going to try to get the bottom of the many stories about the Romans and silver mining in the north. The metals theme continues with stops and stories at a prehistoric barrow at Kirkhoff and a Roman fort, thought by some but not all, to be positioned to protect Roman state lead mining. The episode ends beside the South Tyne at Belting, which tells a different story about mining metals in the North Pennines. There is something romantic about precious metals that seduces even the most Eriodite researcher. Are stories of large quantities of silver rich lead are in the North Pennine veins a myth? Or are they reality? What do the data say? The different ways silver content in rocks was measured doesn't make an evaluation easy, but the bottom line is that across the North Pennines, the percentage of silver present is very low. The ore field is silver poor, not silver rich. Between seventeen twenty nine and eighteen seventy, the two major companies mining and processing lead in the area recovered five million four hundred and fifty thousand ounces around one hundred and fifty tons of silver from one million five hundred and forty two thousand one hundred and eighty four tons of lead concentrate. That's an average of only three point five ounces per tonne of concentrate. The majority of thirty two individual mines in the district recorded less than eight ounces of silver per ton of lead metal. But three mines, Clargill Head, Stowe Crag, and St. John's show much higher levels. St. John's mine, a site of special scientific interest, is an old lead mine two hundred meters south of Tynehead. It was not the most productive of nineteenth century lead mines, but one of the veins recorded forty ounces of silver per ton of lead metal. About a kilometer north is a field, curiously known as the Chesters, on alluvial gravel, pockmarked with diggings. Silver in Galena reported there was also relatively high, and some have linked these workings to the Romans. Elsewhere in the North Pennines, older and unverifiable historical accounts report a mining boom and outputs of up to four tons of silver per year during the twelfth century. If these are true, they suggest that in places, richer silver bearing lead ores may have once been more accessible than known in later periods. Perhaps they were mined from deposits nearer the surface, and it was these much shallower, more argentiferous lead ores that the Romans worked. Why might they be richer in silver? Like the other mineral veins in the Pennines, their primary origin was deep, warm, mineral rich fluids circulating three hundred million years ago. Theoretically, at least, millions of years later, nearer surface water percolating through the veins could have enhanced the silver levels further. If we accept that rich ores did occur in some places, and that they were accessible to early miners, it nonetheless remains true that across the whole ore field the amounts of recoverable silver in galena, lead ore, are extremely modest. There are those who argue that normal mineral economics do not apply when Roman labour, soldiers, slaves, prisoners, may have been free, and ores with very small concentrations of silver could have been processed, or that the lead may have been desilvered to improve its quality. These and other hypothetical societal factors lead some historical and archaeological accounts to imply that silver in the North Pennine Hills was as important as lead to the Romans and a prime reason for their interest. I'm afraid for most geologists this pushes the existing evidence too far. Of course, whatever the scientific facts of the silver resource are, the Romans could have been seduced north by tantalizing tales of fabulous riches in remote mountains. Many people are. Halfway up the side of the South Tan Valley, near a hamlet called Kirkov, are two small, barely noticeable grassy mounds. They are burial cairns, both excavated in nineteen thirty five and one again in twenty fourteen. Although no human remains were found, these are prehistoric burial sites. The recently re excavated mound held artifacts that have allowed archaeologists to deduce the probable gender and possible occupation of the person buried there. Broken fragments of a type of bell beaker pot dated the grave as early Bronze Age, making Kirkhoff an isolated location for something of this date. Other objects provided clues to his status and skills. The most sensational, or at least the most publicized finds, were two matching pure gold hairtress clips, the first found in nineteen thirty five, and the second by four local schoolboys who volunteered to help with the twenty fourteen dig. The other artifacts included a flint core, flakes, an arrowhead, and a saw, a whetstone, a round hammer stone, a small round edged block of sandstone used in metal working, pieces of charcoal and a nodule of iron pyrites. That's fool's gold. The gold hairtress ornaments and the metal working stone are rare. Only one other burial site like it has been found in Britain, the famous Amesbury Archer, from near Stonehenge. These objects point to the Kirkhof man being a craftsman in copper and gold, and archaeologists have inferred he may have been in the North Pennines using his knowledge of metals to prospect for copper. Four thousand years ago, local people may not have known what copper ore malachite was, but they would certainly know their hills and where to find a green rock when asked by someone who did know. While early Bronze Age people seemed to have had little use for lead, its ubiquitous presence in the North Pennines and its close association with copper ore could support the reason he was here. Two other items found in the cairn remind us of something very fundamental, something we take for granted today, but even up to two hundred and fifty years ago was an essential possession, a fire making kit. The flint saw is a striker light, an import whose geological origins are at least as far south as Yorkshire. The pyrite, that's Greek from pyrites lithos, stone which makes fire, can be found locally and is the prehistoric equivalent of a steel. When the pyrite is struck with the flint it makes a spark, which can ignite tinder, often dry moss, lichen or birch bark. Making fire is one of the things that distinguished us humans from animals, and we used two rocks to take that evolutionary step. Seen from above, the multiple rhomboid shape defences of this pennine Roman fort at Whittley Castle, three kilometers northwest of Alston, are striking. The fort sits in dramatic isolation, guarding an ancient road, the Maiden Way. Now known by its probable Roman name, Epiarcum, it is the highest stone built and possibly the best preserved fort in Britain. However, this fort may have had another reason for its location, Roman state protection of the mining and processing of lead ore in the North Pennines, a region that sixteen hundred years later became the largest source of lead in Britain. If the maiden way was merely a road joining places to the north and south, more effective courses could have been chosen, a lowland route via Carlisle, or due north from the Durham Dales. The inference is that the road, and thus Epiarcum, had another purpose, securing the extraction of minerals. Hike the maiden way south of the fort, and you will see fragments of lead ore, that's galena, amongst the stones of the track. There are many galena veins a few kilometers south and east of Epiarcum. At the Roman fort at Bruff on Stainmoor Pass, lead seals were found that were used to identify packages by the Romans. Several of the seals had the stamp of the second cohort of Nervians. They spent some time at Epiarcum. A few seals were marked with the word metal, that's Latin for mines. Could these be labels on consignments of North Pennine's lead ingots, called pigs, destined for York, the south and the continent? Other finds of lead related artifacts, for example at Corbridge, may indicate a northern outlet for pennine mining. Lead pigs with Roman inscriptions have been found near possible mines in Yorkshire and Derbyshire, and it is probable that lead was mined by Iron Age peoples before the conquest. There is support in ancient literature too. Pliny the Elder describes Britain as having abundant mineral wealth, and Tacitus reports Agricola saying to his men that among the prizes of the invasion there would be gold, silver, and other metals. But evidence for Epiarcum being the Roman centre of significant lead mining and processing in the North Pennines remains circumstantial, I'm afraid. An early nineteenth century excavation of the bathhouse floor revealed mortar containing lead mine spar. That's probably crystals associated with veins of galena. Two large lumps of galena were found in the fort in the nineteen sixties. Despite being assayed in the hope of establishing a local and ancient mining source, the heavy weathering of these lumps shows they have lain at the surface for many thousands of years, and so their origin is equivocal. Crucially, in 2007, 2008, a comprehensive English Heritage Field and Geological Survey of the site found no sign of lead, its mining or its processing. Nevertheless, while no lead ingots and mines have been discovered, to many people, the indirect signs of lead exploitation in the North Pennines are compelling. But related, oft repeated assertions that it was silver in the lead oars of these hills that was the prime reason for a Roman presence is a lot less convincing. Available geological data just does not support that. The small hamlet of Beltingham lies south of Barden Mill. It is worth a visit as the little church is in a beautiful setting. It has the stump of an old cross, a Roman altar, a very old ew tree, and graves of the family of the Queen Mother, the Boes Lion family. Just to the northwest of Beltingham is an area of river deposits, sand, pebbles and cobbles beside the South Tyne. They are special because they contain the waste products of lead and zinc mining in the Pennine Hills. The plant colonies that are able to grow in these contaminated locations are very rare. They are called calaminarian habitats. Belting River gravels are a Northumberland Wildlife Trust nature reserve and a site of special scientific interest. Mining of lead and its associated minerals, zinc and fluorite, has taken place for many centuries in the hills and valleys of the North Pennines. The lead and other heavy metals, like cadmium and barium, have been flushed far downstream. These metals which are toxic to most plants settle into the river deposits and the soils that develop on them. The main heavy metal tolerant plants are in quite a small area, and they are spring sandwort, alpine penicres, seat thrift, mountain pansy, and June Heliberine. The condition of this environment is fragile, and it needs to be constantly monitored. Take the walk to Belting from Barden Mill, cross the railway line at the station, go across a little bridge across the Tyne, and then through a beautiful little woodland. You won't be disappointed. So we have ended the first part of our journey opposite Barden Mill, a twentieth century coal mining town on the banks of the South Tyne. By the start of the next episode we will have passed Hayden Bridge, once home to two world famous people, John Martin a Victorian painter of apocalyptic biblical scenes. Hayden Bridge is also the rabbit hole of the poet Philip Larkin and his girlfriend Monica Jones. Look for the blue plaque on the terraced house opposite the co op. In april nineteen sixty two Larkin wrote I thought your little house seemed distinguished and exciting and beautiful. It looks splendid, and it can never be ordinary with the time going by outside. A great English river drifting under your window, brown and muscled with currents. Don't you just envy people who can use the English language like that?