An alluvial tin streamwork adjacent to the Brim Brook

Reasons for Designation

Dartmoor is the largest expanse of open moorland in southern Britain and, because of exceptional conditions of preservation, it is also one of the most complete examples of an upland relict landscape in the whole country. The great wealth and diversity of archaeological remains provide direct evidence for human exploitation of the Moor from the early prehistoric period onwards. The well-preserved and often visible relationship between settlement sites, major land boundaries, trackways, ceremonial and funerary monuments as well as later industrial remains, gives significant insights into successive changes in the pattern of land use through time. 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.

The alluvial tin streamwork adjacent to the Brim Brook survives very well and contains important information concerning the developing technology associated with the exploitation of valley bottom tin deposits. Of particular interest are the range of visually impressive revetted spoil dumps, which highlight and graphically illustrate one of the major alluvial extraction methods.

Details

The monument includes an alluvial tin streamwork situated adjacent to the Brim Brook. The streamwork contains a range of well-preserved earthworks which suggest multi-phase exploitation of the tin deposits. Most of the waste dumps generated during streamworking lie at right angles to the valley bottom and many of them are revetted by drystone walling on their northern sides, facing upstream. Three discrete blocks of this type of streamwork are visible and each is served by a well-preserved leat. Within the northern part of the monument there are a small number of relatively narrow banks lying parallel with the river and these may represent dumps of more recent origin. Within the streamwork there are three rectangular buildings used by the tinners for shelter and storage. All of these buildings have been cut into earlier waste dumps. The northernmost building measures, internally, 5.2m long by 3.2m wide, is defined by a 1.5m wide drystone wall standing up to 1.3m high and is subdivided into two rooms. The interior of the central building measures 4.8m long by 2.1m wide and the surrounding 1.9m wide drystone wall is up to 1.1m high. The southern building is much larger than the others, with internal dimensions of 8.6m long by 3.5m wide.

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.

Legacy

The contents of this record have been generated from a legacy data system.

Legacy System number:

28731

Legacy System:

RSM

Sources

Other
MPP Fieldwork by S. Gerrard, Gerrard, S., (1999)
MPP Fieldwork by S. Gerrard, Gerrard, S., (1999)

End of official list entry

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