| Summary : The site of a Roman settlement associated with mining activities at Charterhouse-on-Mendip, Priddy, Somerset, centred on ST 500 562. Evidence suggests the settlement was occupied from the immediate post-Roman Conquest period to at least the early fourth century. The settlement area includes the sites of a possible amphitheatre and a Roman fortlet, and a possible further Roman sub-rectangular enclosure, although the latter may be of medieval or post-medieval date. It is recognised as one of the most important Roman industrial sites in Britain. The Romans mined lead-ore and smelted this to produce impure metallic lead from which they appear to have extracted a small amount of silver. An English Heritage survey in 2007 characterised the settlement and its relationship with the core mining zones of Blackmoor and Velvet Bottom valleys. It included earthwork survey, and aerial photograph and LiDAR analysis. The survey covered several different areas, and demonstrated that it covered an area of at least 27 hectares. It consists of a regular system of streets adapted to the local topography, which, where visible, divided a series of compound enclosures consisting of a varied layout of building-platforms and yards. The trackways, building platforms (at least 65), and enclosures indicate that there was an unenclosed settlement. However, a possible boundary ditch on the north-east side was identified, beyond which a possible cemetery has been located. Including the forts, and possible amphitheatre, the potential settlement area increases up to 36 hectares. The area of the settlement could potentially expand even beyond this, into unsurveyed areas to the south-east and the probable industrial focus in the Blackmoor and Velvet Bottom valleys. There was no evidence for any form of associated field-system, possibly due to the dangers of contamination from the industrial processes, or perhaps because of an economic focus on mining activities. |
More information : Roman lead-mining settlement centred in the fields called Town Field (ST 502561), and Upper and Lower Rains Batch (ST 502566 and 500563). Remains discovered in the 19th century included building foundations, furnaces with traces of lead ore, layers of charcoal and scoriae, inscribed lead pigs, bronze fibulae,1st and 2nd century Samian and other pottery. Coins ranged from two silver pre-Roman coins to Constantine, with nothing of the later 4th century and a paucity of late 2nd and early 3rd century issues. The only hoard numbered some 900 coins, found in Lower Rains Batch, probably deposited around the time of Carausius. (1-2)
The bulk of the finds is preserved in the Bristol and Taunton museums. The most definite features appear in the field NE of Town Field (ST 503 564) where a criss-cross pattern may represent the plan of part of a Roman or medieval settlement, although bearing some resemblance to Celtic fields. (3)
Roman field-system, in the field NE of Town Field, consisting of square-ish enclosures demarcated by very slight banks, separated by strips of land between 30 and 80 feet in width at a slightly lower level than the enclosures. Trial excavations in 1948-9 showed that the enclosures were bounded by ditches with low spread banks. Finds of pottery included a sherd from an early 3rd century storage jar sealed below the primary silting of one of the ditches. (4)
Tratman believes that the enclosures in the field centred ST 503 564 are part of the settlement, not a field system, and reports a corridored Roman building, at ST 50345626, uncovered during excavations by the University of Bristol Spelaeological Society (UBSS). The earthworks and enclosures, though visible on air photos (for which see ST 55 NW 7) are not surveyable. (5-7)
Traces of a street system at ST 503563 have been recognised on an old air photograph. (8)
Samian ware, unstratified, from Town Field in 1956, found in the reserves of UBSS Museum. Discussed and illustrated. (9)
An account of excavations and field work at Charterhouse-on-Mendip,1960-1967. (10)
Additional reference. (11)
ST 502561: Roman settlement at Town Field, scheduled. (12)
Despite being one of the most important Romano-British extractive centres, Charterhouse has never benefited from detailed research. Little excavation has been done within the settlement. Aerial photographs and fieldwork suggest that occupation extended over at least 12.1 ha (30 acres), being focused around a system of irregular streets defining a row of roughly square plots running east-west with less regular blocks to north and south. Given existing evidence, it is impossible to define the chronology of the mining site, or the precise details of its layout. The history of mining exploitation has been pieced together from the surviving lead pigs. These suggest that after the initial military activity, production passed into the hands of several individuals who might be imperial agents or procuratorial officials, or civilian prospectors in their own right. The lead extraction industry rapidly expanded through to AD 160 after which the inscribed series of pigs comes to an end. Demand may well have declined after this, although occupation of the site certainly continued into the early fourth century judging from the coin issue. (13)
Other early investigations included excavation of four areas within the settlement by Malcolm Todd, University of Exeter, in 1993-95, including the Roman fortlet. The second phase of the use of the fort was interpreted as an area for processing galena, and perhaps the extraction of lead and silver. (14)
However, the English Heritage survey in 2007 now suggests an Iron Age origin for the enclosure, with a subsequent Roman fort constructed within the enclosure bounds.
A Roman settlement associated with mining activities at Charterhouse-on-Mendip, Priddy, Somerset, centred on ST 500 562, and recognised as one of the most important Roman industrial sites in Britain. Silver, lead, zinc, iron, and haematite are all likely to have been extracted, and at least 11 lead ingots have been found which are believed to have originated from the site. The available evidence suggests the settlement was occupied from the immediate post-Roman Conquest period to at least the early fourth century, although it is not clear which elements were occupied contemporaneously. An English Heritage survey in 2007 characterised the settlement and its relationship with the core mining zones of Blackmoor and Velvet Bottom valleys, and included earthwork survey, and aerial photograph and LiDAR analysis.
The survey covered several different areas - Hill Ground, Lower Rains Batch, Marthas Lot, Charterhouse Green, Great Cowleaze Pasture, Plentys, Hundred Acre, Upper Rains Batch, Grays Ground, and Further Blackmoor, and has demonstrated that it covered an area of at least 27 hectares. It consists of a regular system of streets adapted to the local topography, which, where visible, divided a series of compound enclosures consisting of a varied layout of building-platforms and yards. Trackways, building platforms (at least 65), and enclosures indicate an unenclosed settlement, although a possible boundary ditch on the north-east side was identified, beyond which a possible cemetery has been located. Including the military monument of the fort and possible amphitheatre, the potential settlement area increases up to 36 hectares. The area of the settlement could potentially expand even beyond this, into unsurveyed areas such as Home Ground to the south-east and the probable industrial focus in the Blackmoor and Velvet Bottom valleys.
There was no evidence for any form of associated field-system with the settlement, possibly due to the dangers of contamination from the industrial processes, or perhaps because of an economic focus on mining activities. (15-16)
The settlement area includes Scheduled Ancient Monument Nos SO218 (an earthwork enclosure comprising a large circular depression surrounded by a bank, considered to be a Roman amphitheatre, reusing an extant prehistoric monument), SO219a and b (a sub-rectangular enclosure visible as earthworks), and SO220 (a Roman fortlet). The mining works lie immediately to the south of the settlement (Scheduled Ancient Monument SO508), and consist of prehistoric to post-medieval features, much of which has obscured the Roman mining evidence. Reference to the Scheduling notices can be made for more details. (17)
The suggestion that ‘Silver, lead, zinc, iron, and haematite are all likely to have been extracted’ (Sources 15-16) from this site is a distortion of what the excavations of Malcolm Todd showed. There is much evidence for the extraction of lead at Charterhouse and some evidence for the extraction of silver from the lead. There is no evidence for the extraction of zinc, iron, or hematite. During excavations in 1995, a fragment of metallic zinc was found but zinc frequently condenses in lead smelting furnaces when the lead-ore is contaminated with zinc minerals such as smithsonite (which occurs at Charterhouse). There is no evidence that the Romans purposely extracted zinc at Charterhouse or anywhere else in the world. The Romans certainly knew how to produce brass from zinc oxide by the so-called cementation process, but metallic zinc is not thought to have been purposely made anywhere in the world until Medieval times. The walls of the lead veins at Charterhouse are, in part, coated with ‘brown hematite’; iron-ore (mixed hematite and goethite) so that a certain amount of ‘hematite’ would have been excavated together with the lead-ore (or while searching for lead-ore). There is no evidence that the Romans purposely extracted hematite at Charterhouse, and no evidence that they smelted iron there although they could have done both. (18)
Further reference (19) |