Reasons for Designation
Approximately 10,000 lead industry sites are estimated to survive in England,
spanning nearly three millennia of mining history from the later Bronze Age
(c.1000 BC) until the present day, though before the Roman period it is likely
to have been on a small scale. Two hundred and fifty one lead industry sites,
representing approximately 2.5% of the estimated national archaeological
resource for the industry, have been identified as being of national
importance. This selection of nationally important monuments, compiled and
assessed through a comprehensive survey of the lead industry, is designed to
represent the industry's chronological depth, technological breadth and
regional diversity.
The ore works were an essential part of a lead mining site, where the mixture
of ore and waste rock extracted from the ground were separated (`dressed') to
form a smeltable concentrate. The range of processes used can be summarised
as: picking out of clean lumps of ore and waste; breaking down of lumps to
smaller size (either by manual hammering or by mechanical crushing); sorting
of broken material by size; separation of gravel sized material by shaking on
a sieve in a tub of water (`jigging'); and separation of finer material by
washing away the lighter waste in a current of water (`buddling').
The field remains of ore works include the remains of crushing devices,
separating structures and tanks, tips of distinctive waste from the various
processes, together with associated water supply and power installations, such
as wheel pits and, more rarely, steam engine houses.
Simple ore dressing devices had been developed by the 16th century, but the
large majority of separate ore works sites date from the 18th and 19th
centuries, during which period the technology used evolved rapidly.
Ore works represent an essential stage in the production of metallic lead, an
industry in which Britain was a world leader in the 18th and 19th centuries.
Sites are common in all lead mining areas and a sample of the best preserved
sites (covering the regional, chronological, and typological variety of the
class) will merit protection.
Limekilns were first used in Britain in the Roman period when lime was used in
mortar. In the medieval period, the replacement of timber buildings by stone
structures and the construction of churches, religious houses and
fortifications, led to a great demand for mortar and hence the need for
limekilns. Many kilns were constructed for a particular building project.
By the end of the medieval period quicklime, the product of the limekiln, was
being used in agriculture as a means to neutralise soil acidity and break down
heavy clay soils. Agricultural use was particularly important in the 18th and
19th centuries. By the post-medieval period quicklime was also used on lead
mining sites as a cheap alternative to gunpowder for rock blasting.
The remains of Beans and Bacon, Fiery Dragon, Old Eye and Cod Beat mines are
well preserved and include a diverse range of components relating to the
mining of these veins. The workings have particularly early origins and
preserve an unusual and extensive range of evidence for different rock
breaking techniques. The standing, earthwork, buried and rock cut remains
combined with the documentary sources provide evidence for both the historical
and technological development of what was once a far more extensive,
multi-period mining landscape. They incorporate a wide range of mining and
processing features, which enable the development of the mine working and its
chronological range to be reconstructed. The large veins, smaller scrins,
shafts, hillocks and other extraction features provide evidence for methods of
extraction whilst other processing areas will contain deposits showing the
effectiveness of these techniques. The mining remains also provide an insight
into the Derbyshire Barmote Court system of mining and the constraints this
imposed on the miners of the area.
The limekiln is also well preserved and provides important stratigraphical
information about the continuity in use of the mines. It also retains
important and rare archaeological evidence relating to the production and use
of quicklime in this part of Derbyshire.
Details
The monument includes the earthwork, buried, standing and rock cut remains of
Beans and Bacon, Old Eye, Fiery Dragon and Cod Beat lead mines and a limekiln
480m south of Blakelow Farm. The monument is situated on Bonsall Moor, to the
south of Tower Lane, and is defined in three separate areas of protection.
Geologically, the monument lies to the north of the Great Bonsall Fault, with
the lead veins running through gently folded limestone and lying at a
stratigraphic horizon beneath the Matlock Lower Lava.
Ore accounts dating from 1541 provide the earliest record of mining on Bonsall
Moor but most of the surviving surface remains represent mining activity of
the 18th and 19th centuries. The mines would have been worked under the
jurisdiction of the Barmote Courts, the legal administrative unit governing
Derbyshire lead mining. The Derbyshire system of mining was largely based on
local mining customs and consisted of individual groups of miners or small
mining companies working relatively short lengths of the vein.
The monument survives as a series of earthwork, buried, standing and rock cut
remains which include a wide belt of lead bearing veins and scrins (narrow
mineral deposits). The Beans and Bacon, Old Eye and Fiery Dragon veins are
situated in the westernmost area of protection, roughly parallel to each other
and aligned approximately east to west. Between Beans and Bacon and Old Eye
veins are a series of short scrins which are aligned south west to north east.
Cod Beat scrins, which lie in the other two areas of protection, are aligned
north to south.
Beans and Bacon mine is situated at the western end of the monument just south
of, and roughly parallel with, the northern edge of the area of protection.
Within this area are a series of five coes (stone built shelters or sheds) one
of which is a double coe with the Beans and Bacon founder shaft in one
compartment. Shafts along this mine have been the subject of investigations
and have been shown to display similar evidence to that recorded at Gorseydale
lead mine, which lies approximately 350m to the north west of Beans and Bacon
and is the subject of a separate scheduling. The workings are fairly small
scale but they contain evidence of all types of rock breakage; plug and
feather, gad and wedge, pickwork and also gunpowder blasting. These remains
and those at Gorseydale are the only known examples of such multiple breakage
techniques within single, small mines. A shaft, situated approximately 65m
east of the north west corner of the monument, gives access to the largest and
deepest workings in the Beans and Bacon mine. The entrance shaft, workings and
internal shafts have been descended in excess of 55m beneath the surface. Old
Eye vein is situated just north of the southern boundary of the westernmost
area of protection, and, for the most part, runs roughly parallel with Beans
and Bacon mine. The course of the vein is marked by grassed shallow open cuts
(veins worked open to daylight), prospecting holes, and shafts. The founder
shaft is situated within a low walled, ruinous coe close to the southern edge
of this area of protection. Approximately 150m to the east of the founder
shaft is a limekiln which is built into the vein structure. The kiln is well
preserved and survives as a dry stone wall which spans the vein with an arched
entrance on the western side.
To the north of, and towards the eastern end of Old Eye vein are a series of
scrins aligned south west to north east. At the northern end of the scrins is
a ruined coe adjacent to which is a flue like structure which extends
westwards into a small plantation. The flue is visible for approximately 50m
but terminates at its eastern end near a collapsed shaft.
Fiery Dragon vein runs roughly east to west in the eastern end of the largest
area of protection and is marked by lines of hillocks and shafts. Just south
of the main vein are four, deep, conical open holes; these represent open pit
extraction of a locally enriched ore-body. The eastern and central portions of
Fiery Dragon mine have been seriously degraded by former hillocking and deep
trenching operations and are not therefore included in the scheduling.
The remaining two areas of protection contain the remains of Cod Beat mine
which is represented by deep, straight and vertical sided scrins which were
worked as open cuts. Both these areas of protection contain several parallel
scrins which run in a north to south alignment and which are quite different
in character to the remains of the other mines. Between the two smaller areas
of protection are further remains of both Fiery Dragon and Cod Beat mines but
these have been degraded by fluorspar extraction which was carried out in the
1950s and are not therefore included in the scheduling.
The mines are given added importance by the part they played in early
geological debates in to the origin of rock. The debates, which began in the
late 18th century, centred on whether or not all rocks were sedimentary or
whether some were the result of igneous activity. The toadstones, local to the
area, featured heavily in this debate with specific reference being made to
sites on Bonsall Moor.
All modern fences, gates and stiles are excluded from the scheduling although
the ground beneath them is included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
