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Visitors touring the mines
The Dolaucothi Gold Mines (pronounced [ˌdɔlaiˈkɔθɪ] ; Welsh : Mwynfeydd Aur Dolaucothi) (grid reference ), also known as the Ogofau Gold Mine, are ancient Roman surface and underground mines located in the valley of the River Cothi, near Pumsaint, Carmarthenshire, Wales. The gold mines are located within the Dolaucothi Estate which is now owned by the National Trust.
They are the only mines for Welsh gold outside those of the Dolgellau gold-belt, and are a Scheduled Ancient Monument. They are also the only known Roman gold mines in Britain, although it does not exclude the likelihood that they exploited other known sources in Devon in South West England, north Wales, Scotland and elsewhere. The site is important for showing advanced Roman technology.
Archaeology suggests that gold extraction on this site may have started sometime in the Bronze Age, possibly by washing of the gold-bearing gravels of the river Cothi, the most elementary type of gold prospecting. Sextus Julius Frontinus was sent into Roman Britain in AD 74 to succeed Quintus Petillius Cerialis as governor of that island. He subdued the Silures, Demetae and other hostile tribes of Roman Wales, establishing a new base at Caerleon for Legio II Augusta and a network of smaller Roman forts fifteen to twenty kilometres apart for his Roman auxiliary units. During his tenure, he probably established the fort at Pumsaint in west Wales, largely to exploit the gold deposits at Dolaucothi. Frontinus later restored the Aqueducts of Rome and wrote the definitive treatise on 1st century Roman aqueducts, the two-volume De aquaeductu .
That gold occurred here is shown by the discovery of a hoard of gold ornaments in the 18th century. Objects found included a wheel brooch and snake bracelets, so named because they were soft enough to be coiled around the arm for display. All the objects are now held in the British Museum, and displayed in the Romano-British gallery. A sample of gold ore was found at the site by Henry De la Beche in 1844, confirming the presence of gold.
Evidence from the fortification (known as Luentinum from details given in Ptolemy's Geographia ) and its associated settlement show that the Roman army occupied the fort from c. AD 78 to c. 125. However, coarse ware and Samian ware pottery recovered from a reservoir (Melin-y-Milwyr) within the mine complex show that activity at the mines continued until the late 3rd century at least. Since Ptolemy's map dates to about 150, it is likely that it continued being worked until the end of the 3rd century if not beyond.
The Romans made extensive use of water carried by several aqueducts and leats, the longest of which is about 7 miles (11 km) from its source in a gorge of the river, to prospect for the gold veins hidden beneath the soil on the hillsides above the modern village of Pumsaint. Small streams on Mynydd Mallaen, the Annell and Gwenlais, were used initially to provide water for prospecting, and there are several large tanks for holding the water still visible above an isolated opencast pit carved in the side of the hill north of the main site. The larger aqueduct from the Cothi crosses this opencast, proving the opencast to be earlier.
The water was stored in the tanks and then released suddenly, the wave of water sweeping away the soil to reveal the bedrock and any gold-bearing veins beneath. Pliny the Elder gives a dramatic account in his Naturalis Historia of the method, possibly derived from his experiences in Spain. The method is known as hushing and survived in use until the 19th century in Britain, and into the 20th century in the goldfields of Africa. A not dissimilar method is used today in exploiting alluvial tin deposits, and is known as hydraulic mining. A smaller scale version of the same method is placer mining, and both may have been used to work alluvial placer deposits next to the river Cothi itself, judging by a large aqueduct which tapped the river a mile or so upstream, and enters the site at a low level compared with the other known aqueducts on the site. The water supply of the aqueducts was also used for washing crushed gold ore, and also possibly driving stamping mills for comminution of the ore (Lewis and Jones, 1969).
One of the first aqueducts was built at a high level on the east slope of Allt Cwmhenog and tapped a small stream about 2 miles (3 km) away. There is a large tank at its end, where it sweeps around the brow of the hill onto the west side of the ridge. A gold vein must have been discovered here, because there is a large opencast below the tank. Yet the larger and longer aqueduct (with a gradient of 1 in 800) taps the River Cothi about 7 miles (11 km) to the north-east and traverses the same opencast, so must be later in date.
By contrast, several tanks found on the site did not show a vein, so were abandoned. The tank shown at right occurs not far from the north opencast and was probably intended to find the limits of the deposit located in the adjacent opencast (Tank A in the schematic diagram below). It clearly didn't find the vein, and was thus abandoned. The water supply may have been obtained from a small leat run from a stream up the main Cothi valley before the much larger aqueduct was constructed.
Prospecting was successful and several opencasts are visible below the large tanks built along its length. The only exception is the final and very large tank, below which are two reservoirs. It is likely that this complex was used for washing powdered ore to collect the gold dust.
More leats and tanks can be found below the line of the main aqueduct, some of which are shown on the map of the site. They surround the lip of the very large opencast and the tank shown at right is one which was built on the main aqueduct. It was successful in finding a vein, judging by the opencast below, but must have been modified later to feed a washing table built to the left-hand side (near the figure in the picture), probably to wash the crushed ore from the same opencast working. It is labelled Tank C in the schematic diagram. Similar tanks occur below as the Romans followed the large vein down to the road and the main opencast. Most of the opencast workings must therefore be Roman in origin, since one of the aqueducts has been confirmed by carbon 14 dating as to predate all modern workings. Just by the road itself the Carreg Pumsaint has been erected in the space beside a large mound, now thought to be a dump of waste material from mining activities.
The existing ponds above and below the minor road from Pumsaint to Caeo, were probably part of a cascade for washing ore, the upper tank having yielded large quantities of Roman pottery from c. AD 78 to at least 300 (Lewis, 1977; Burnham 2004). The upper pool is known as Melin-y-Milwyr, or the soldiers' mill, an intriguing name that implies that watermills may have been used here during the Roman period. Alternatively, it may have been a sequence of washing tables for the crushed gold ore. A large-scale mill complex is known from Barbegal in southern France, where no less than 16 mills (in two lines of 8 each) were built into the side of a hill and supplied with water from a single aqueduct. There were two lines of parallel overshot mills, the outflow from one feeding the next below. The mill supplied flour to the region. Moreover, Roman engineers used sequences of reverse overshot water-wheels to dewater mines, and the deep workings at Dolaucothi produced a fragment of such a wheel during the 1930s when deep mining operations were resumed. Sequences of such wheels increased the lift, and one extensive sequence of 16 wheels was found in old Roman mine workings on the Rio Tinto river in the 1920s. The wheels were arranged in pairs and could lift water about 80 feet (24 m) from the bottom of the mine there.
The tank at the head of the small road from Pumsaint to Caio was thought to be modern since it still holds water. However, when the level of the water was low in 1970, it yielded large quantities of Roman pottery which show that it is of Roman origin and built early during their exploitation of the mines. The section shows that it was connected to a smaller tank just below the modern road by a drystone culvert in a cascade. The lower tank also holds water but is in an advanced state of eutrophication. The collection of fragments included Samian ware and coarse ware from over 100 separate pots, and must have fallen into the reservoir when the mines were in full operation. Analysis of the pottery fragments showed a distribution of ages from the late 1st century AD through to the end of the 4th century. Since the fort and fortlet under the present village of Pumsaint ends in the middle of the 2nd century, it shows that mining continued for a long time after the military evacuation.
It implies that there is a large mining settlement in the vicinity of the village of Pumsaint which has yet to be found.
The exact function of the cascade is related to the methods of extracting the final traces of gold from the crushed ore. There were probably washing tables between the two tanks so that a gentle stream of water could be used to wash the ore on the rough surface of the tables, the finer gold being caught in the rougher parts of the tables, and removed at the end of the process. The cascade would probably have been built towards the end of the 1st century when underground mining commenced following opencast development.
This site yields some of the earliest evidence anywhere for the Roman use of water-powered trip hammers to crush ore (Burnham 1997). The ore was probably crushed on the famous Carreg Pumsaint, a block of stone erected many years ago before the Romans had left the site. There are parallels with similar stones at other ancient Roman mines in Europe, and the hollows in the block were formed by a trip hammer probably worked by a water wheel or a "water lever". Such a water-powered hammer would have been moved regularly as each hollow became too deep, so producing the series of overlapping oval hollows in its surfaces. The hammer head must have been of substantial size judging by the width of the hollows shown in the drawing. The stone is the only example so far discovered at the site, but is not unique, and Burnham refers to others of similar shape from Spain. As one side of the stone became worn, it was simply turned to reveal another side, so the block could be re-used several times. When found years after the Romans had left, in the Dark Ages, it gave rise to the legend of the five saints, who left the impression of their heads in the stone after being found asleep by the devil.
They followed the veins with shafts and tunnels, some of which still exist on the site. The remains of Roman dewatering machines were found during the 1880s and the 1920s when the Rio Tinto mines in Spain were being mined by opencast methods.
At Dolaucothi, a similar discovery was made in 1935 during mining operations, and it included part of a reverse overshot water-wheel which is now in the National Museum of Wales. It was found with burnt timbers, suggesting that fire-setting was used to help break up the hard quartz in which the gold was trapped. A similar but larger wheel was rediscovered during mine operations at Rio Tinto in Spain, and is now in the British Museum, where it is displayed prominently in the Roman gallery. The Spanish example included a sequence of no fewer than 16 reverse overshot water-wheels, each pair of wheels feeding water to the next set in the sequence. Each wheel would have been worked like a treadwheel, from the side rather than at the top, but it would have been a hard and lonely activity for the miners working these wheels lifting water from the mine bottom. Since the fragment of a reverse overshot water-wheel was found 160 feet below any known adit or stope, it must have been part of a similar sequence at Dolaucothi to that in Spain. Gold mining was sophisticated and technologically advanced at Dolaucothi, suggesting that the Roman army itself pioneered exploitation at the site. The construction of such dewatering machines is described by the Roman engineer Vitruvius writing in 25 BC, and their use for irrigation and lifting water in thermae was widespread.
At another part of the mine, on Penlan-wen, water would have been in short supply; a siphon could have transferred water from the main aqueduct or one of its tanks, but remains unproven. The vein carries along the hill for some considerable distance, and has been trenched out. This method involved excavating the vein vertically down while keeping the top open. However, ventilation becomes a problem when fire-setting is used, so three long adits were driven in from the hillside to the north. They are much wider than normal galleries, suggesting that their primary purpose was to allow circulation of air through the trench and permit safe fire-setting. The upper two adits are still open to the trench, but the lowest one is currently blocked.
Although there is nothing directly comparable with Dolaucothi in Britain in terms of the extensive hydraulic systems, there are many other known Roman mines in Britain, some of which seem to show traces of hydraulic activity. They include the extensive remains of lead mining at Charterhouse in the Mendips, Halkyn in Flintshire, and many areas in the Pennines. Dolaucothi is most directly comparable with gold mines in the Carpathian mountains of Transylvania in modern Romania, at Rosia Montana, and with the Roman gold mines in north-west Spain, such as the very much larger site of alluvial mining at Las Medulas and Montefurado. The Romans may have used slave labour taken from the local area to work the mine, although the army itself was probably most directly involved, especially for their engineering skills in surveying and building aqueducts, reservoirs and water tanks or cisterns.
There is some evidence that some of the gold was worked at the site, judging by the finished brooch shown above, as well as other finished gold products.
A part engraved jewel has also been found in the vicinity. Such activities would have needed skilled, not slave labour. No workshops or furnaces have yet been found, but it is likely that both existed on site. Ingots of gold would have been easier to transport than dust or nuggets, although a high-temperature refractory furnace will have been needed to melt the gold, which has a melting point of 1,064 °C (1,947 °F). Pliny mentions such special furnaces in his Naturalis Historia. A workshop will have been vital for building and maintaining mining equipment such as the drainage wheels, flumes for washing tables, shuttering for aqueducts, crushing equipment and pit-props. Official mints would have produced gold coins, a key component of Roman currency. After the military occupation the mine may have been taken over by Romano-British civilian contractors some time after 125, although the final history of the site has yet to be determined.
Following the Roman departure from Britain in the 5th century, the mine lay abandoned for centuries. There was a revival in the 19th century and attempts to make successful ventures at the site in the early 20th century, but they were abandoned before the first world war. In the 1930s a shaft was sunk to 430 feet (130 m) in an attempt to locate new seams. Falling into disrepair and unsafe due to flooding at its lower levels, the mine finally closed in 1938. It was during this period that ancient underground workings were found, and the fragment of the dewatering mill discovered within. The extensive surface remains, especially the traces of hydraulic mining, were to be discovered only in the 1970s by intensive fieldwork and surveying.
Between 1975 and 2000 the lease to the underground workings at Dolaucothi was held by Cardiff University. Students from the School of Engineering were largely responsible for the renovation of the underground workings that were made safe for tourists. The mine was extensively used as a training mine for Mining Engineering and Exploration Geology students under the supervision of Alun Isaac, Alwyn Annels and Peter Brabham. Students from the School of Earth Sciences carried out an active gold exploration programme using surface and underground diamond drilling techniques, geochemical soil sampling and geophysics. Geological exploration was carried out by students using both surface and underground drilling methods. The ore processing waste tailings dam was also sampled, mapped geophysically and assessed for its Gold potential. The mine was extensively mapped and a library of Dolaucothi data is still held at the School of Earth & Ocean Sciences at Cardiff University. Cardiff University finally gave up the lease to the underground workings in 2000 due to the closure of its BSc Mining Engineering degree course. Photographs of surface and underground activities from the Cardiff University archives can be found from the links below.
Although there is yet no comparable site in Britain, it is likely that field work will locate other mines, simply by tracing the remains of aqueducts and reservoirs, and often, if not usually, aided by aerial photography. Physical remains like tanks and aqueducts are often recognised by the shadows cast by the structures in oblique lighting conditions. Thus Tank A was first seen in early morning light when the sun's rays cast an oblique light across the hill (Allt Cwmhenog) on which the structure is situated.
The lead mines of Nantymwyn near Rhandirmwyn village some 8 miles (13 km) to the north may also have been first worked by the Romans, judging by hushing tanks and aqueducts found there in the 1970s both from fieldwork and aerial photographs. They occur at the top of the mountain called Pencerrig-mwyn, and the veins were followed underground by several tunnels leading to the workings. Inside, the veins have been removed and debris carefully stacked within the stope. The workings lie far above the later modern mines and processing plant (now derelict). The later mine was once the largest lead mine in Wales.
There are Roman forts at Llandovery and Bremia (fort) near Llanio, and as of 2003, in Llandeilo.
The National Trust has owned and run the Dolaucothi gold mine and Dolaucothi Estate since 1941 when it was bequeathed by descendants of the Johnes family who had owned the mine and large surrounding estate since the late 16th century. The University of Manchester and University of Cardiff were active in exploring the extensive remains in the 1960s and 1970s and Lampeter University is now closely involved with the archaeology of the site. The National Trust organises guided tours for visitors, showing them the mine and the Roman archaeology.
Mining is the extraction of valuable minerals or other geological materials from the Earth, usually from an ore body, lode, vein, seam, reef or placer deposit. These deposits form a mineralized package that is of economic interest to the miner.
A leat is the name, common in the south and west of England and in Wales, for an artificial watercourse or aqueduct dug into the ground, especially one supplying water to a watermill or its mill pond. Other common uses for leats include delivery of water for mineral washing and concentration, for irrigation, to serve a dye works or other industrial plant, and provision of drinking water to a farm or household or as a catchment cut-off to improve the yield of a reservoir.
Placer mining is the mining of stream bed (alluvial) deposits for minerals. This may be done by open-pit or by various surface excavating equipment or tunnelling equipment.
A trip hammer, also known as a tilt hammer or helve hammer, is a massive powered hammer. Traditional uses of trip hammers include pounding, decorticating and polishing of grain in agriculture. In mining, trip hammers were used for crushing metal ores into small pieces, although a stamp mill was more usual for this. In finery forges they were used for drawing out blooms made from wrought iron into more workable bar iron. They were also used for fabricating various articles of wrought iron, latten, steel and other metals.
Welsh gold is gold that occurs naturally in two distinct areas of Wales and highly prized because of its origin and scarcity. One area it is found in is North Wales in a band stretching from Barmouth, past Dolgellau and up towards Snowdonia. This was mined at several mines, the largest of which were the Gwynfynydd Gold Mine, near Ganllwyd, and the Clogau Gold Mine near Bontddu. In South Wales, it is found in a small area in the valley of the River Cothi at Dolaucothi where it is known to have been mined by the Romans.
Pumsaint is a village in Carmarthenshire, Wales situated half way between Llanwrda and Lampeter on the A482 in the valley of the Afon Cothi. It forms part of the extensive estate of Dolaucothi which is owned by the National Trust.
The ancient Romans were famous for their advanced engineering accomplishments, although some of their inventions were improvements on older ideas, concepts and inventions. Technology for bringing running water into cities was developed in the east, but transformed by the Romans into a technology inconceivable in Greece. The architecture used in Rome was strongly influenced by Greek and Etruscan sources.
A stamp mill is a type of mill machine that crushes material by pounding rather than grinding, either for further processing or for extraction of metallic ores. Breaking material down is a type of unit operation.
Las Médulas is a historic gold-mining site near the town of Ponferrada in the comarca of El Bierzo. It was the most important gold mine, as well as the largest open-pit gold mine, in the entire Roman Empire. Las Médulas Cultural Landscape is listed by UNESCO as a World Heritage Site. Advanced aerial surveys conducted in 2014 using LIDAR have confirmed the wide extent of the Roman-era works.
The technology history of the Roman military covers the development of and application of technologies for use in the armies and navies of Rome from the Roman Republic to the fall of the Western Roman Empire. The rise of Hellenism and the Roman Republic are generally seen as signalling the end of the Iron Age in the Mediterranean. Roman iron-working was enhanced by a process known as carburization. The Romans used the better properties in their armaments, and the 1,300 years of Roman military technology saw radical changes. The Roman armies of the early empire were much better equipped than early republican armies. Metals used for arms and armor primarily included iron, bronze, and brass. For construction, the army used wood, earth, and stone. The later use of concrete in architecture was widely mirrored in Roman military technology, especially in the application of a military workforce to civilian construction projects.
Luentinum or Loventium was a fort and mining settlement in the Roman province of Britannia. It was associated with the Dolaucothi Gold Mines and its remains lie beneath the adjoining village of Pumsaint in the Welsh county of Carmarthenshire. It lay between similar forts at Llandovery and Bremia near Llanio, and some distance away from the fort at Llandeilo. The Roman road Sarn Helen linked Luentinum with Llanio and Llandovery.
Mining was one of the most prosperous activities in Roman Britain. Britain was rich in resources such as copper, gold, iron, lead, salt, silver, and tin, materials in high demand in the Roman Empire. The Romans started panning and puddling for gold. The abundance of mineral resources in the British Isles was probably one of the reasons for the Roman conquest of Britain. They were able to use advanced technology to find, develop and extract valuable minerals on a scale unequaled until the Middle ages.
Roman technology is the collection of techniques, skills, methods, processes, and engineering practices utilized and developed by the civilization of ancient Rome .The Roman Empire was a technologically advanced civilization of antiquity. The Romans incorporated technologies from the Greeks, Etruscans, and Celts. The technology developed by a civilization is limited by the available sources of energy, and the Romans were no different in this sense. Accessible sources of energy, determine the ways in which power is generated. The main types of power accessed by the ancient Romans were human, animal, and water.
Frequently used in mines and probably elsewhere, the reverse overshot water wheel was a Roman innovation to help remove water from the lowest levels of underground workings. It is described by Vitruvius in his work De architectura published circa 25 BC. The remains of such systems found in Roman mines by later mining operations show that they were used in sequences so as to lift water a considerable height.
Fire-setting is a method of traditional mining used most commonly from prehistoric times up to the Middle Ages. Fires were set against a rock face to heat the stone, which was then doused with liquid, causing the stone to fracture by thermal shock. Some experiments have suggested that the water did not have a noticeable effect on the rock, but rather helped the miners' progress by quickly cooling down the area after the fire. This technique was best performed in opencast mines where the smoke and fumes could dissipate safely. The technique was very dangerous in underground workings without adequate ventilation. The method became largely redundant with the growth in use of explosives.
Hushing is an ancient and historic mining method using a flood or torrent of water to reveal mineral veins. The method was applied in several ways, both in prospecting for ores, and for their exploitation. Mineral veins are often hidden below soil and sub-soil, which must be stripped away to discover the ore veins. A flood of water is very effective in moving soil as well as working the ore deposits when combined with other methods such as fire-setting.
Mining archaeology is a specific field well-developed in the British Isles during recent decades. A reason of ongoing interest in this field is the particular bond between regional history and the exploitation of metals. References to mines in the area exist in Strabo's works. However the first accomplished study on the topic was attempted by Oliver Davies in 1935. Other momentous researches were that of geologist John S. Jackson about mines in Ireland and Lewis, Jones in Dolaucothi goldmine in Wales, and the pioneering work of Ronald F. Tylecote. Moreover, in the 1980s and 1990s a new generation of amateurs and scientists began investigations in different locations in the British Isles, including Duncan James on the Great Orme's Head, Simon Timberlake with the Early Mines Research Group at sites in Wales and William O'Brien in Ireland.
Afon Annell is a small river in Carmarthenshire, Wales.
Mining in the Upper Harz region of central Germany was a major industry for several centuries, especially for the production of silver, lead, copper, and, latterly, zinc as well. Great wealth was accumulated from the mining of silver from the 16th to the 19th centuries, as well as from important technical inventions. The centre of the mining industry was the group of seven Upper Harz mining towns of Clausthal, Zellerfeld, Sankt Andreasberg, Wildemann, Grund, Lautenthal und Altenau.
Mynydd Mallaen is an expansive plateau to the northwest of Cilycwm in northeast Carmarthenshire, Wales. It forms part of the Cambrian Mountains massif, and is north-west of the Black Mountain (range) in the Brecon Beacons. It takes the form of an undulating plateau with steep slopes dropping away to the Towy valley to the east and those of the Gwenffrwd, Nant Melyn and Afon Cothi to the north and west. Its highest point of 1516 feet or 462m at OS grid reference SN 723455 is surmounted by two Bronze Age cairns known as Crugiau Merched. Caeo Forest covers much of the southern flanks of the hill and smaller forests also cover its eastern slopes. Much of the native woodland consists of sessile oak groves, especially on the valley sides. The human population is very low, being restricted to hill farms engaged in sheep farming, and some holiday cottages.