Devon County Geological Sites

Site reference no. SX76NW2 Name: Brookwood Mine

District: Dartmoor National Park Parish: West Buckfastleigh (South Hams) National grid ref: 71456755-71778755 OS sheets: 1:50k 202 1:25k OL28 1:10k SX76NW GS 1:50k 338

GridRef x y Lat Long SX714675 271400 67500 50.493151 -3.8143826

Locality description (address): Brookwood Mine (South Devon United) south of the R. Mardle on the Brook Manor estate.

Nature of site: Disused copper mine with dumps, shafts, ruined mine buildings and associated mine features in valley-side woodland.

Geological / geomorphological features: Mine dump [71456756], greenish grey slate (Upper Devonian, Kate Brook Slate?) is seen in a small exposure with shallow southerly-dipping cleavage. Mineralised material shows a complex paragenesis. The earliest lode material appears to be dark quartz-chlorite with traces of pyrite, chalcopyrite and arsenopyrite. Pink veinlets composed of adularia and quartz and joints coated with white mica/chlorite cut the earlier lode material. Later multiple quartz veining, brecciation and development of chalcedony occur. Purple, green and colourless fluorite sometimes associated with chalcopyrite is common. Siderite altered to limonite occurs in cavities and green copper secondary minerals coat joints. Dump [71778755] is essentially similar to the first. There is some complex ore with pyrite, chalcopyrite, fluorite and sphalerite. Later quartz-siderite mineralisation with a little chalcopyrite. Adularia veins earlier than fluorite. Rarely galena is associated with chalcopyrite. Rare erythrite coats joints. Industrial archaeology. A wheel pit is connected by a leat to the lake which was probably originally dammed for this purpose. There are remains of mine buildings in the woods above the dumps together with shafts and traces of trenching on the backs of the lode

Reasons for registration as a County Geological Site: The mineralisation associated with the mine shows a complex and interesting sequence of formation which makes the dumps an interesting subject for study and educational purposes.

Site sensitivity: None

Safety: Generally safe with care

Interest groups: Schools. Years 5-11: Years 12-16: Years 17-18. University. Undergraduate - Research Professional geologists - Amateur geologists - General public.

Access and Parking: Access by permission only. Best access is along the metalled drive from Brook Mill. Parking for cars and minibuses

Date of assessment (V = visited) : V 30th October 1997 R T Taylor

Site owner : Mr and Mrs A Hornsey, Brookwood Manor, Buckfastleigh. Devon. Tel. 0364-642494

Other comments: An attempt to rework the dumps for fluorite in the 1970’s was abandoned because of copper contamination.

References: DINES, H.G. 1966. The metalliferous mining region of south-west England. Memoirs of the Geological Survey of Great Britain. 2 vols., 795 pp. London, HMSO. (Reprinted with addenda and corrigenda 1988) .