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.
Thieveley lead mine is a rare example in north west England of a site
displaying evidence of features relating to lead mining in the early 17th
and mid-18th centuries. It contains a range of features associated with
mining during these periods including shafts, spoil tips, ore-processing
areas, a buddle and the buried remains of a smelt mill. This latter
feature is considered to be the only known example of foot-powered bellows
operating in a smelt mill of this date in Lancashire and Yorkshire, and
thus reflects one of the technological developments in use at smelt mills
prior to the later widespread use of waterwheels to power bellows for
increasing the heat in the smelting process.
Details
The monument, which is divided into two separate areas of protection,
includes the earthworks and buried remains of Thieveley 17th century lead
mine. The eastern area close to the remains of Thieveley Farm, includes
shafts, spoil mounds, an ore processing area and the buried remains of an
early smelt mill, while the western area close to Black Clough contains a
shaft, a leat, the remains of a buddle, and an area of ore processing debris.
The first known mining at Thieveley commenced in 1627 when Robert Hartley
discovered lead ore while digging a trench to divert water into the farmyard
at Thieveley Farm. By 1629 a small smelt mill which is thought to have
utilised foot-powered bellows for increasing the heat in the smelting process
was operating here. Two years later this mill had become an ore store after
being replaced by a larger mill in the valley bottom. Documentary sources
indicate that mining may have ceased after the mid-1630s, however, it is
probable that the Thieveley Farm and Black Clough areas were reworked by the
Clitheroe Mining Company for a short period sometime between 1753 and 1766.
To the west of the remains of Thieveley Farm there is an area of lead ore
dressing debris with larger and more regular shaped debris at the eastern end
suggesting the site of a former structure presumed to be the smelt mill. The
remainder of this area appears to be where the ore was dressed ready for
smelting. There are two terraces, the higher containing larger waste
suggesting that the ore was broken by hand to remove unwanted rock, the lower
containing smaller waste suggesting sieving to remove smaller particles of
shale. To the south and south west of the remains of Thieveley Farm there are
four largely infilled lead shafts. The lowest of these displays exposed spoil
immediately below it, the one close to a drystone wall corner has a grassed
over tip, the one closest to the farm consists of a hillside depression with
loose stones in the bottom, and the one to the south west of the farm
consists of a large depression 3m in diameter encircled by a grassed over
ring mound of spoil. Two small adjacent mounds are also thought to be spoil
tips.
At SD86632776, to the east of Black Clough, there is the site of a shaft
consisting of a mound partly devoid of vegetation and containing grit and
shale debris with traces of barytes, a vein mineral associated with lead.
Just below this mound there is a leat or water channel ending at a square pit
which is thought to be the location of a buddle. A buddle was a device for
separating pulverised veinstone into its various minerals. Fine veinstone was
shovelled into the conical centre of the buddle where water, fed by the
leat, and a paddle system, agitated the mixture and gradually distributed it
across the floor, leaving the heavier lead particles near the centre and
washing the waste to the edges. An area of ore processing debris, covered by
thin vegetation, extends downhill below the buddle. All drystone walls,
fences, fence posts, gates and gateposts are excluded from the scheduling,
although the ground beneath these features is included.
MAP EXTRACT
The site of the monument is shown on the attached map extract.
