Details

The monument includes an alluvial tin streamwork situated at the foot of a
steep sided valley formed by the River Lyd. The streamwork contains a range
of well preserved earthworks which suggest multi-phase exploitation of the tin
deposits. The southern limit of the streamwork is denoted by the River Lyd,
whilst most of the northern edge is defined by a wide channel which lies
immediately next to the Bridestowe/Brentor parish boundary bank. The area
between these two prominent features includes a large number of distinctive
parallel linear earthworks which represent the dumps from alluvial
streamworking. The dominant alignment of these dumps is north east to south
west, meaning that most lie approximately at right angles to the River Lyd.
There are however, three distinct areas where the dumps lie approximately
parallel with the river. A programme of survey, excavation and augering has
revealed the general sequence of events and identified areas where waste
slimes from the dressing process were dumped.
The forest tracks leading through the monument are excluded from the
scheduling, although the ground below is included.

MAP EXTRACT
The site of the monument is shown on the attached map extract.
It includes a 2 metre boundary around the archaeological features,
considered to be essential for the monument's support and preservation.

Source: Historic England

Reasons for Scheduling

On Dartmoor, tin streamworks represent intermittent tin working activity
dating from the medieval period to the 20th century. During this time
previously abandoned works were often brought back into production, while some
streamworks are still not exhausted, raising the possibility that they may
become viable once again.
Streamworks exploited tin deposits that had been detached from the parent lode
and redeposited by streams and rivers within either alluvial deposits in
valley bottoms or in eluvial deposits in shallow, steeper tributaries on
hillsides. The technique involved large scale extraction (which has left major
earthworks visible in the landscape) and the use of water to separate tin from
the lighter clays and silts which contained it. The water derived either from
canalised streams or reservoirs fed by specially constructed leats which can
be seen running for several miles along the contours of many hillsides. The
streamworks themselves survive as a series of spoil dumps, channels and
disused work areas which indicate their character and development.
Streamworking was particularly prevalent on Dartmoor, being by far the most
numerous and extensive type of tinwork on the moor. Remains are to be found in
most valley bottoms and on many hillsides, where they make a dominant
contribution to landscape character as well as providing unusually detailed
evidence for medieval industry. Streamworks on Dartmoor will be considered for
scheduling where they are well preserved and representative of the industry in
this area, or where there is a demonstrable relationship with medieval and
later settlement and its associated remains.

Despite agricultural activity and afforestation, the alluvial tin streamwork
in Lydford Woods survives well and contains information concerning the
developing technology associated with the exploitation of valley bottom tin
deposits. Of particular interest, is the evidence for the reuse of disused
tyes as dumping areas for dressing wastes.

Source: Historic England

Sources

Books and journals
Gerrard, S, Lydford Woods alluvial tin streamwork, (1997)

Source: Historic England