The truth of Nature lieth hid in certain deep mines and caves.
FRANCIS BACON: Advancement of Learning
THE Peak District as a whole constitutes an important source of mineral wealth so that mining and quarrying form one of the chief economic activities. These operations moreover cause considerable modification of the natural landscape and give rise to characteristic features which are sometimes unsightly.
When the Romans came to Britain they were drawn to the wilds of the Peak District by two attractions—the warm springs and lead—the one for pleasure and the other for profit. The mention of warm springs naturally calls to mind those of New Zealand and other parts of the world. Nevertheless the two belong to quite different categories. Hot springs are associated with volcanic regions and may be regarded as belonging to the declining phases of volcanic activity. Their waters are to a large extent “juvenile”; that is to say have been released from the interior of the earth and now appear at the surface for the first time. The warm springs of The Peak on the contrary consist of water which has descended from the surface to such depths that it has become heated and has returned to issue forth again at a higher temperature.
Though today there are no volcanoes to add to the interest of the Peak District, it was a minor volcanic region at the time when the Carboniferous Limestone was being formed. From its volcanoes lava streams issued occasionally and, flowing over the sea floor, became interbedded with the limestone. Though liquid lava is popularly called “molten rock,” it is, strictly speaking, a hot solution of many different minerals and is called “magma.” In course of time the deeply-seated reservoir, from which the magma came, cooled and various minerals, such as quartz and felspar, crystallised out and formed solid rock-like granite. Many other minerals containing tin, copper, lead and the like remained mixed together either in solution or as vapours. This mixture poured up along cracks into the overlying rocks. These reacted chemically upon one another as they cooled and, crystallising out formed valuable ores in a more or less orderly succession. Tin ore was formed at an early stage and at a deep level, next came copper ore and at a still later stage lead ore towards the outer extremities of the fissures. Thus the lead veins and lodes of the Peak District came into being. Rain, frost and rivers working ceaselessly after the Carboniferous period and later during the Tertiary era gradually removed the mighty over-burden of Millstone Grit, Coal Measures and of other rocks laid upon the region during the Mesozoic Era until at long last the very roots of the region were exposed and the valuable mineral lodes made accessible to the future miner.
LEAD AND LEAD-MINING
Lead, for which Derbyshire has so long been famous, occurs in the metallic form as galena (lead sulphide). Only very small quantities of white lead ore or cerussite (lead carbonate) have been found, though past workings from the White Rake on Tideswell Moor are recorded.
Unlike some lead ore that of Derbyshire is poor, in silver. There is no real evidence that the Roman workings in the county were richer in this respect than those of later date. There is some doubt as to whether the Romans ever recovered silver as they did in Mendip, despite the finding of pigs of lead inscribed EX ARG and EX ARGENT. The Ball Eye Mine near Matlock is the only place where more than a negligible amount of silver-lead has been recorded. A very small percentage of zinc as well as traces of antimony sometimes occur with the lead.
The workable ore occurs in the Carboniferous Limestone as veins filling vertical fissures. These veins, known in Derbyshire as “rakes,” appear to follow local anticlines and have been exploited individually over considerable distances and are still traceable by the long narrow spoilbanks generally running from east to west (Fig. 11, see here, and Plate XXI, see here). Less frequently, lead may occur at the intersection of vertical joints in the rock, and these concentrations are called “pipes.” As already noted, the ore and associated minerals were deposited in fissures and joints in the limestone through heated water and vapours rising from igneous material at depth. That the mineralising agents remained in the limestone is due to the former cover of impermeable shales, lavas and other rocks preventing their escape.
Lead is accompanied by various secondary minerals called gangue minerals, chiefly fluorspar, barytes and calcite, which usually occur in a definite sequence in the vein. Very broadly fluorspar, one of the commonest of these minerals, is predominant towards the eastern end of the larger veins but diminishes in proportion westwards, while calcite and to a less extent barytes become correspondingly more abundant. In the past the gangue minerals were valueless, but they are now of considerable economic importance. Demand for them has resulted in a new phase of mineral working in the limestone area, leading to the exploitation of spoil banks where large accumulations still occur and to the re-opening of old lead mines.
Among the more important lead veins worked in the past are those of the Castleton area (Dirtlow and Moss Rakes), Stony Middleton (Dirty, White and High Rakes), Youlgreave (Long and Lady Rakes), those of the Wirksworth and Winster district, and those around Matlock.
Lead production reached its zenith in the late eighteenth century but remained fairly high until decline set in after 1850. While mines continued to close throughout Derbyshire, one venture proved exceptionally rich. This was the Mill Close Mine on the west side of Darley Dale which, after being worked in the eighteenth century, was reopened in 1861. Though the amount produced fluctuated with prevailing prices, the mine remained active for a long period; the war of 1914–18 stimulated a great increase in output which continued to rise until the early thirties, when the quantity of ore obtained each year far exceeded that for the whole country in the late eighteenth century. In 1931 out of 29,000 tons raised in Britain, 26,000 tons came from the Mill Close Mine. For many years it remained the largest lead-mine in the country. The introduction of electric pumping prolonged its life, for the workings, descending to a depth of 1,000 ft., eventually reached the water-table in the limestone. It was disastrous flooding in 1940 which unhappily brought operations to an end.
Among the few other lead-mines left, the Glebe Mine at Eyam (which is also important for fluorspar) and the new drift working near the High Tor at Matlock should be mentioned. The latter is an attempt to re-open by modern methods workings abandoned by earlier miners, and is so far successful.
There is an extensive literature on the history of Derbyshire lead-mining and its related laws and customs, but only a brief account is appropriate here in order to explain some of the interesting relics which the industry has left on the landscape. Of lead working in Roman times there is both actual and documentary evidence. Into the former category come the several pigs of lead which have been found bearing Roman inscriptions. We also know that it was exported to the homeland in Italy. Later on, the Domesday Survey mentions three lead-mines at Wirksworth, and one each at Crich, Bakewell, Ashford and Matlock, but it is strange that no reference is made to the Castleton district for it was always a rich area. The Odin Mine close to Castleton is certainly one of the oldest in The Peak.
In the Middle Ages lead production rose to a new importance and, besides its extensive use at home for piping and the roofs and windows of our cathedrals and churches, the metal ranked with wool as one of the chief exports from this country. In Derbyshire nearly the whole mining area from Wirksworth to Castleton became known as the King’s Field from which a royalty was levied on the ore obtained. Mining operations were regulated by a code of laws based largely on local customs which had become blessed by the sanction of time. Many of these laws survive and meetings of the old Barmote Court presided over by the Barmaster are still held at Wirksworth to administer them.
The King’s Field covered parts of both the High and Low Peak. While Wirksworth was the seat of the Barmote Court for the Wirksworth Hundred (Low Peak), its counterpart for the High Peak was at Monyash. A Barmaster held office at each place and at least during the seventeenth century several deputy Barmasters were appointed in other centres such as Matlock, Wensley, Brassington and Tissington. The Barmote Court met twice a year with a jury consisting of twenty-four experienced miners from among whom twelve were chosen for each meeting of the Court. The Court continues to meet twice yearly in the Moot Hall at Wirksworth, where the Standard Dish of the Low Peak miners is still used. The dish is a heavy oblong vessel of bronze, made in the fourth year of the reign of Henry VIII and holds fourteen pints or about 60-70 pounds of lead, varying according to the purity of the ore. There was no standard dish for the High Peak, but those commonly used at Monyash held sixteen pints. By Acts of Parliament passed in 1851 and 1852 for the High Peak and the Wirksworth Hundred respectively, the Barmote system was modified. Thus in addition to the Barmaster a steward was appointed by the Crown. The jury was reduced to twelve men, six being chosen for each court, while the standard measuring dish for both divisions became one of fifteen pints.
Under the ancient mining laws the essential rights remaining today are those which entitle the finder of a lead vein to have sufficient land and enough water to work it irrespective of the ownership of the land. The presentation of a dish of ore to the Barmaster frees the working and thereafter every thirteenth dish is payable as a royalty to the Lord of the Field. From before the Norman Conquest until the reign of Elizabeth I the mining rights were held by the Crown and royalties were therefore paid to the sovereign, but Queen Elizabeth relinquished the rights and among those to whom many of them subsequently passed was the Devonshire family, who thus gained a source of wealth. Today the royalty, or Queen’s “lot,” as it is called, is payable to the Duchy of Lancaster. Whilst it may be thought that the mining laws which were invariably upheld by the Barmote Court operated somewhat harshly against the interests of farmers and land-owners, it must be remembered that the laws were in being when much of the land was still in waste and that later owners obtained land, having knowledge of the miners’ rights.
Among the miners themselves the ancient rights and customs were jealously upheld, and to the layman a good deal of mystery shrouded their activities because of the extraordinary vocabulary of phrases and technical terms which they used. Most of these terms were quite meaningless to those outside the industry. Many of them have been recorded in a poem by Edward Manlove, published in 1653. The author, who was Steward of the Barmote Court at the time, described in execrable verse the rights of the miner and the procedure of registering and working his claim. As an illustration the following extract occurs towards the end of the poem:
Most of the Customes of the Leadmines, here
I have described, as they are used there;
But many words of art you still may seek,
The Miner’s Tearms are like to heathen Greek,
Both strange and uncoth, if you some would see,
Read these rough verses here composed by me.
Burnings, Polings, Stemples, Forks, and Slyder,
Stoprice, Tokings, Sole-trees, Toach and Ryder,
Water-holes, Wind-holes, Veyns, Coe-shafts and Woughs,
Main Rakes, Cross Rakes, Brown-henns, Budles and Soughs.
An interesting case of the application of the mining laws occurred only a few years ago. A quarryman at Wirksworth discovered a lead vein while at work. He staked his claim in the traditional manner, in this instance to part of the quarry face. The Barmote was called and upheld the claim, and as a result the quarry-owners were obliged to pay a sum to the workman in order to regain the title to the limestone face traversed by the vein. From this it must not be imagined that all the discoveries of lead in the past were made accidentally. Very many were the outcome of patient and skilful search, often made by men who had an eye for the nature of the ground, however rudimentary their ideas of geology may have been.
RELICS OF LEAD WORKING
Mining over a long period has left characteristic scars upon much of the limestone country. In many parts the ground is strewn with hollows denoting old shafts with their attendant spoil heaps now grass-covered. Some of the longer rakes can be traced for miles by narrow ridge-like spoil banks, stretches of which are sometimes planted with trees to prevent grazing animals from being endangered by lead poisoning (Plate XXI, see here). Then there are the traces of early smelting. Until modern times smelting was done in primitive hearths called “boles.” The hearth consisted of a shallow hole excavated on the brow of a hill facing the prevailing wind. The ore was broken into small pieces by men, cleaned and washed by women and girls. It was then placed in the hole mingled with wood, fired, and then covered with turf. Fanned by the wind, the heat became so intense that the melted lead flowed out into channels where it cooled and solidified into blocks called pigs which could be readily transported. The inn called the Pig of Lead at the end of the Via Gellia may well serve as a reminder of former traffic in that area.
The bole hearths account for the frequency of the name Bole Hill in The Peak. On some of the hills bearing this name the actual hearth site is marked to this day by a patch of sterile ground. Their distribution is at first a little surprising for they mostly occur on the adjoining gritstone, especially on the East Moor and the grit-shale outliers, while only one or two are to be found on the limestone itself. The higher ground formed by the gritstone offered greater exposure to the wind and the surrounding slopes provided a plentiful supply of timber for fuel. Another advantage was that the hearths lay near to Chesterfield, which was for a long period the chief market for Derbyshire lead.
At an early date charcoal displaced wood as a fuel. It is not known when this practice began but it undoubtedly occurred while the bole hearths were still in use. Later on smelting methods were improved by the introduction of charcoal furnaces with a stone hearth and by the use of bellows to supply the draught of air. So far as is known, however, no traces of such furnaces remain.
Later still, the evidence of lead smelting is to be sought not on the hills but in the valleys by the side of the streams. This relates to a further change in technique which took place in the second half of the eighteenth century and which really marks the beginning of modern methods. From this time onwards the ore was smelted in a rever-beratory furnace called a cupola, the earliest of which was erected at Ashover in 1747. The cupola consisted of a furnace containing the fire at one end, separated from the ore by a brick wall over which the flame was drawn. The furnace roof sloped down towards the other end where a flue led into the chimney. The siting of these smelters on the bank of a stream enabled water wheels to operate the bellows, while the valley location favoured the use of coal and subsequently coke for firing the furnace.
With these improvements much larger quantities of ore could be treated, and the cupola served as the chief means of lead smelting during the period of maximum production in the late eighteenth century and the early nineteenth. Ruins of some of the cupola buildings can still be found. Vestiges of one are to be seen in a meadow at Alport just below the confluence of the Lathkill and Bradford streams. Two others stand in Middleton Dale just above Stony Middleton, while in other cases only a name recalls their existence such as Cupola Cottage on the roadside north of Baslow and the Cupola Footpath near Hathersage.
After the mid-nineteenth century the Matlock district became the chief area for smelting. Though further technical advances were made, the principle of the reverberatory furnace remained as the basis for the operation. One of the oldest works belonging to this period, situated at Lea, was finally demolished only a decade or so ago. The important smelting and recovery plant attached to the Mill Close Mine at Darley Dale, using the most modern methods, is still active, treating lead scrap as well as the small quantities of ore still raised in Derbyshire.
One last but important reminder of the lead-mining industry is seldom observable. This relates to the elaborate means by which many of the deeper workings were drained. In the early phases mining presented little difficulty for the ore veins outcropped at the surface. After these superficial resources were exhausted, the mines were sunk deeper and deeper until eventually the water-table was reached. Some shafts went to a depth of 200 ft. before the amount of water became unmanageable. The incoming water was at first removed by pumping or by small drainage tunnels. During the eighteenth century much larger underground tunnels known as “soughs” were excavated to convey the water to the river Derwent. These were often several miles long, being cut through the limestone and lined with limestone blocks where they passed through the shales. They were works of considerable magnitude and undertaken at great cost. The first was the Cromford Sough, which was completed about 1690 at a cost of £30,000. It served to drain a number of mines in the Wirksworth district, though it brought financial loss to its promoters. Much later this sough was put to an unforeseen use when in 1769 Richard Arkwright bought it in order to supply his first cotton mill at Cromford with water power. The Stoke Sough (1732) drained mines around Eyam and reached the Derwent south of Grindleford. The Hill Carr Sough (1753) leading from the mines at Alport and Youlgreave to the river just south of Rowsley was four miles long. The Meerbrook Sough (1772) starting at Wirksworth reached the river near Whatstandwell. For the past fifty years it has supplied the Ilkeston and Heanor Water Board, yielding 12 to 15 million gallons daily.
Around the old lead workings the accumulated waste heaps are largely made up of the other minerals that accompanied the ore in the veins. Today anyone who is so inclined can make quite a useful little collection of these minerals. The lead or galena shows as sparkling square fragments. The fluorspar occurs in clusters of cubic crystal, often honey-coloured, sometimes colourless or tinged with purple. Less abundant are the dark brown crystals of zinc blende which when broken look like resin. Barytes is common but because it is unattractive is frequently passed over. It occurs as shapeless cream-coloured masses with part of the surface covered by a rust-coloured deposit. Calcite, commonest of all, takes the form of whitish or semi-transparent crystals.
All these minerals, together with a number of others also found in the limestone, are of economic value and are worked commercially to a greater or lesser extent. Some of them, such as fluorspar, are most readily obtained from the spoil heaps and old lead workings, a few of which have been re-opened for the purpose. Fluorspar itself is now in considerable demand in modern industry. Most of the output is consumed as a flux in steel-making, while the best grade with a high fluoride content is used in non-ferrous metallurgy and in the ceramic and chemical industries. Production has given rise to renewed activity in several of the old lead-mining areas of which the chief are the Castleton-Bradwell-Eyam and the Matlock-Wirksworth districts. In recent years numbers of local men, many of them farm-workers, have been drawn to spar-winning with pick and shovel. Some of them work only at week-ends or in the evenings, while others have found it profitable to make it a full-time venture, seeking the mineral not only from spoil heaps but from old lead-mines, paying a royalty to the local landowner and selling the output to a company which owns the mineral rights. Should they actually find lead, the traditional procedure still applies, by which the claim is taken to the Barmote Court, and after the first dish of ore is made over to the Crown the mine is freed for working regardless of who owns the land.
Of special interest is the variety of fluorspar with a rich purple or amethyst colour sometimes verging to yellow. This is the well-known Blue John used for making ornaments. Its occurrence is confined to the Castleton neighbourhood, where the Blue John Mine, the chief source of supply, is situated. The deep tint of this handsome mineral is thought to be due to staining caused by the inclusion of hydrocarbons during crystallisation. Evidence for the existence of hydrocarbons is found in the small seepages of bitumen (elaterite) from the limestone, as in the Winnats Pass, suggesting the organic constituents of the limestone as a possible source. Besides the Blue John Mine, the mineral has been worked from the Treak Cliff Mine and the Old Tor Mine in the Winnats. While it is likely that this variety of fluorspar was worked much earlier, actual records of its use for ornamental purposes date only from the mid-eighteenth century. Though much skill was necessary in shaping the spar owing to its brittleness, ornaments of great beauty were made in Castleton and Buxton as well as in London. The remarkable candelabra commissioned by Robert Adam and now in the Victoria and Albert Museum, was made by Matthew Boulton of the Soho Foundry, Birmingham. Eventually exports of spar were made to France for the production of massive ormolu work and from this trade comes one of the several explanations of its popular name, for the French are said to have called it “bleu-jaune,” whence the corruption “blue john.” It seems, however, that the mineral had received its name before this time. In recent years the finest spar with its rich amethyst colour has become relatively scarce, but the making of less expensive ornaments, obtainable in most of the Derbyshire tourist centres, continues.
Another of the vein minerals, barytes (barium sulphate) or “heavy spar,” is worked in crystalline form from old lead-mines and spoil heaps. After grinding to a fine white powder, it is used in making paint, while being heavy and chemically stable it is effective as a filling material in the paper and textile industries. Calcite (calcium carbonate) is the commonest of all the vein minerals and also occurs in limestone fissures. It is worked from the Long Rake near Youlgreave, where its uniform quality, owing to the vein being free from lead and not discoloured by other mineral matter, gives it commercial value. Ochre (red oxide of iron) is sometimes found in pockets in the limestone. Where it occurs in sufficient quantity, as in the Via Gellia and at Matlock, it is worked as a source of colouring matter.
Of the major rock formations within the Peak District, the Carboniferous Limestone forms the main basis of the quarrying industry. In addition to the large-scale extraction of stone from numerous quarries, there are a few localised workings of the chert and silica deposits associated with the limestone. Quarries are a characteristic feature of the landscape and are at the same time unsightly. Mainly for this reason the largest centres of production around Buxton (including Miller’s Dale), Matlock and Wirksworth have been excluded from the National Park. The quarries remaining within the Park, are, with few exceptions, on a smaller scale. They produce less than a million tons of stone annually compared with a total output for the Peak District as a whole—well over six million tons.
The shales and grit-shales are of no economic importance except in the Hope Valley, where the Edale Shales are worked with the adjacent limestone (Nunlow Beds) for the manufacture of cement. The resulting works form the largest industrial site in the National Park (Fig. 11, see here). As to the gritstone, which provides relatively thin flagstones formerly used for roofing as well as massive sandstones suitable for building, its exploitation has greatly declined. Even the use of the Kinderscout Grit at Stancliffe and Darley Dale, which has a high reputation as a building-stone, has diminished, chiefly because cheaper materials are now favoured. Many famous buildings have been erected in this stone. Chatsworth House and The Crescent at Buxton are examples in Derbyshire, while St. George’s Hall at Liverpool provides an instance farther afield. The output of pulp-stones and grindstones, the latter chiefly for glass-grinding, continues on a small scale largely from quarries around Hathersage. Groups of abandoned grindstones, some only roughly hewn, others almost finished, can be seen by the rambler in many places as he clambers along the gritstone “edges.” They are interesting relics of what was once a considerable industry. Such can be found along Stanage Edge (Plate XXIIa, see here), Curbar Edge and Froggatt Edge, at Burbage End and in a roadside quarry between Grindleford and Hathersage. Perhaps the best quality stone for the purpose was that provided by the Chatsworth Grit between Hathersage and Padley, hence the name Millstone Edge. Towards the end of the eighteenth century cheaper stone imported from France caused the industry to decline and eventually brought it to an end. This activity actually survives on a small scale at Tansley near Matlock, where the Chatsworth Grit again provides suitable material. Here at the Derbyshire Oaks Quarry the making of grindstone is still carried on, chiefly for use by the file manufacturers of Sheffield, although some are even exported to distant countries such as India. A new use for some of the discarded stones has recently been found as boundary signs on the main roads at points of entry to the National Park. Mounted edge-wise on a massive stone pedestal, they afford an appropriate emblem (Plate XXIIb, see here).
Considering the extent of the gritstone surface, which forms the entire northern moorland as well as the flanking East and West Moors, the number of active quarries is remarkably small compared with even fifty years ago. In fact abandoned quarries, moss-covered and partly overgrown with vegetation, are a typical feature of the gritstone country. They are almost as numerous as the old houses and farm buildings which were built from the stone they supplied. The decline in the demand for stone, except in small quantities, is in marked contrast to the ever-expanding demand for limestone and it is unlikely that gritstone quarrying will ever again be required to meet the needs of great enterprises such as railway building and reservoir construction which brought it prosperity a few generations ago. High quality gritstone is still worked on a small scale at Stanton Moor and elsewhere.
In the east on the outskirts of Sheffield, yet within the National Park, the clays of the Lower Coal Measures are worked for fireclay. These clays are siliceous and withstand high temperatures, so that they are used for the manufacture of firebrick and furnace linings. The workings, which are near Bradfield, are small and, being chiefly in the form of adits, do not seriously disfigure the surface. A similar deposit of fireclay is worked in the extreme west on Bakestonedale Moor. From beneath the clay in both localities, gannister, another refractory material, is obtained. Old coal shafts which are still recognisable on Bakestonedale and Axe Edge Moors were in production about a hundred years ago but the coal was poor and very sulphurous. As Miss Nellie Kirkham reminds us, perhaps the most interesting feature of these shafts was their names: Black Clough, Wooden Spoon, Crash-away.
LIMESTONE IN ABUNDANCE
To return to the limestone. To the modern chemical industry in its various forms the Carboniferous or Mountain Limestone of north Derbyshire is of great importance. In the first place, its purity in terms of the calcium carbonate content is exceptionally high and stone of this degree of purity exists here in greater quantity than elsewhere in the country. Moreover, its mode of occurrence favours large-scale methods of quarrying, crushing and burning, while its location is within a short distance of the principal consuming centres in south Lancashire and Cheshire and the West Riding of Yorkshire. These advantages are greatest in the Buxton and Miller’s Dale district, where the Chee Tor and Miller’s Dale Beds yield high quality stone to a depth of several hundred feet. This is the area of huge quarries including the Tunstead Quarry with its enormous working face nearly a mile long, which is by far the largest in the country. The distribution of the quarries was originally determined by accessibility to the railways, and as time went on a confusion of branch lines arose threading their way into the works from the main lines. Over 90 per cent of the lime produced in the Peak District now comes from this area. The same beds are also worked at Stony Middleton, while the other centres of limestone production include Bradwell and Eldon Hill, together with Matlock and Wirksworth in the south.
Of the total output of lime from the works in The Peak, nearly 40 per cent is consumed by the chemical and allied industries. Some 20 per cent is used in the preparation of agricultural fertilisers and about 12 per cent in the building trade. Large quantities of stone are used as a flux in iron and steel production and also as road metal. Much of the output from within the National Park is quarried for road metal which reflects the poorer quality of the stone available except of course that found at Stony Middleton. During the nineteenth century and earlier, however, most of the stone was burned to provide lime for the fields and it is impossible to go far in this part of Derbyshire without seeing vestiges of the numerous kilns erected for that purpose.
Limestone-working, whether upon the plateau or in the dales, affects the amenity of the countryside. Apart from the disfiguring effect of the quarry face, smoke from the kilns makes the working all the more conspicuous and may also become a nuisance, while the coating of fine grey dust which covers the surrounding vegetation, sometimes stifling its growth, is particularly distressing. Unfortunately the situation is likely to become worse rather than better, for the demand for lime continues to increase, besides which some of the large quarrying concerns have reserves of limestone lying inside the boundary of the National Park. This is the sort of issue which may one day have to be faced squarely if national parks are to fulfil their purpose, although nobody should suppose that amenities can be preserved entirely without cost. Recognising the importance of this matter, the Peak Park Planning Board issued a statement of policy in 1952. This made clear that future quarrying projects would receive the closest scrutiny and that where possible operation should take place outside the Park. In any event the Board reserved the right to exclude quarrying altogether from certain parts which are at present quite unspoiled and are of the highest scenic value.
Before leaving the subject of limestone, reference should be made to two special varieties which have been used for purposes quite different from those already mentioned. One is the Hopton Wood Marble and the other the once famous Ashford Black Marble. Neither of them is a marble in the strict geological sense, though both are decorative stones and take a high polish. That from Hopton Wood, south of the Via Gellia, is a cream-coloured fossiliferous stone belonging to the Chee Tor and Miller’s Dale series, which affords a valuable building material chiefly for interior work. Stone from these quarries was used extensively for gravestones by the Imperial War Graves Commission. To those interested in historic building-stones, the old quarries in Ricklow Dale near Monyash, whence came the famous Derbyshire grey “marble” in the eighteenth century, are worth seeing. Even their eerie desolation is impressive.
At Ashford-in-the-Water near Bakewell traces can still be found of the Black Marble workings of over a century ago. This marble was obtained from beds of the limestone containing carbonaceous and clayey matter. It provides a handsome material for ornamental, including inlay work, and was once the basis of an important local industry now largely forgotten. It was certainly worked in the sixteenth century, and in 1748 a marble mill was set up in Ashford village, where the industry survived until about 1905. Far earlier, however, is the first evidence of the use of Black Marble, for a dressed slab of it was found in a prehistoric burial site in the tumulus on Fin Cop, the hill about two miles north-west of Ashford. In the immediate neighbourhood of Ashford old underground workings can be traced in the Rookery Plantation just west of the village and opposite on Arrock Hill to the south of the Wye.
OTHER QUARRY PRODUCTS
Associated with the Carboniferous Limestone are several other materials of commercial value which contribute to the quarrying industry. Chert, a siliceous mineral closely resembling flint, which occurs locally in the limestone, is worked near Bakewell for use in the Staffordshire potteries. One of the two remaining sources, the Holme Bank quarry, was first opened by Sir Josiah Wedgwood nearly two hundred years ago. Silica deposits, forming large pockets in the limestone, form the basis of an important industry producing refractory materials. These pocket silicas, as they are called, are found near Friden and Parsley Hay to the east of the Ashbourne-Buxton road. They are composed of brightly-coloured sands, gravels and clays. The largest of them are several acres in extent and reach to a depth of over 100 feet. The workings are therefore in the form of pits. To geologists the origin of these deposits has proved puzzling, although more is now known about them than was the case even a decade or so ago. It is agreed that they are accumulations filling large sink-holes in the limestone. In the view of Dr. P. E. Kent they are mainly of Mesozoic age and represent the subsided remains of former widespread sediments of Permo-Triassic times. There is good reason to suppose that the deposits have been preserved by sinking progressively farther down as the sink-holes deepened through later geological times. Some limestone-shale (Pendelside) material also occurs, relict from a period before the overburden was stripped from the limestone, while the latest deposits are represented by clays containing silicified wood of Tertiary age and by patches of Boulder Clay, each member of the succession being preserved beyond the normal limits through continuing local subsidence.
The various igneous rocks which are found in the Carboniferous Limestone of The Peak are chiefly used as road-making material. Some of the dolerites and basalts provide very durable stone of high crushing strength and are therefore suitable for roads bearing heavy traffic. The chief centre of production is at Calton Hill near Taddington, where the quarrying of basalt, begun in 1906, has been considerably extended in recent years. Here the amount of waste caused by the presence of volcanic ash with the basalt, is particularly great, so that ugly spoil heaps now surrounding the hill occupy a large part of the workings. Another source of basalt is from the Waterswallow Quarry north of Buxton. Clearly the excellent roads of the Peak District owe much to the availability of local materials. Were it not for these, suitable stone would have to be brought from more distant areas such as Charnwood Forest or the Lake District.
REFERENCES
HOPKINSON, G. The Laws and Customs of the Miners within the Wapentake of Wirksworth. (1644)
TAPPING, T. Treatise on the High Peak Mineral Customs and Mineral Courts Acts, 1851 and 1852. (1854)
STOKES, A. H. Lead and Lead-mining in Derbyshire. Trans. Chesterfield and Derbys. Inst, of Engineers: 8 (1880–81) and 9 (1881-92) (1854)
THORPE, H. Derbyshire Lead Production. Derbyshire Countryside (Jan, 1934)
TRAILL, J. G. The Geology and Development of the Mill Close Mine, Derbyshire. Econ. Geol.: 34 (1939)
LUGGARD, C. E. Derbyshire Lead-Mining Customs in the Sixteenth Century. Jour. Derbys. Arch, and Nat. Hist. Soc.: LXV (1940)
PORTEOUS, C. The Beauty and Mystery of Well-dressing. Pilgrim (1949)
O’NEAL, R. A. H. Derbyshire Lead and Lead Mining: A Bibliography, 2nd ed. Derbyshire County Library, Matlock (1960)