Seathwaite Copper Mines
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Condition (Natural England)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| SD265994 | — | Favourable | 0.83 | 2021-11-04 |
| SD266996 | — | Favourable | 0.57 | 2009-03-11 |
Geology & landscape
Geological Period: Ordovician
Landscape processes: Volcanic / Igneous
Description
Description Seathwaite Copper Mines lie high on the Coniston Fells to the south of Wrynose Pass, west of Ambleside. The site comprises two areas of land along Tarn Head Beck, north west of Seathwaite Tarn and includes the mine tips and adits of disused copper mines. The Lake District forms a geographically well defined base metal orefield. The sulphide mineralisation occurs as vein deposits and is notably diverse in terms of both the nature of the ores and their age. Four quartz veins which trend east west at Seathwaite cut through Ordovician rocks of the Borrowdale Volcanic Group. The mineralisation is only sparsely visible in situ in the surface outcrops of the veins but is well seen in dump materials. The mineralisation is of the 'chalcopyrite arsenopyrite' type, best known from the nearby Coniston Mines. However, the assemblage at Seathwaite is more varied and the sequence of mineralisation particularly of the copper sulphides more complex than has been shown for Coniston, making comparison between the two important in understanding the paragenesis of the metalliferous ores. This list of copper sulphides includes bornite, digenite, djurleite, chalcocite and covellite. Of particular interest is the rare copper bismuth sulphide, wittichenite. Seathwaite is the first confirmed occcurrence of this mineral in the British Isles.