Gonamena Mine, St Cleer, Cornwall, England, UKi

Regional Level Types
Gonamena Mine	Mine
St Cleer	Civil Parish
Cornwall	County
England	Constituent Country
UK	Country

A small copper mine, located in the valley west of Caradon hill and south of Minions. The sett occupies a narrow tract of land between West Caradon Mine in the west and south and South Caradon Mine in the east and is bounded to the north by South Wheal Phoenix. The workings concentrate along a shallow ridge at the northern end of the valley, which separates two small streams that flow southwards and unite south of Gonamena hamlet to form the river Seaton. The property contains three EW-trending copper lodes, from north to south Sara's Lode (Sarah's Lode), Taylor's Lode and Gilpin's Lode. They are heaved several fathoms by two NS-trending crosscourses on which two shafts were sunk, Hingston's Shaft on the east slope of the ridge and Sara's Shaft on its west slope, 290 yards west of Hingston's Shaft, which pass through Sara's Lode at the 158 fm and 70 fm levels, respectively. Between the crosscourses, the lode was developed from both shafts, but the workings do not connect at all levels. Several drives west of Sara's Shaft beyond the western crosscourse extend into the West Caradon sett. Crosscuts driven along the crosscourses at several levels did not prove any further lodes to the north, but connect to Taylor's and Gilpin's lodes in the southern part of the sett. Gilpin's Lode actually crops out in the West and South Caradon setts, but, owing to its northerly dip and the shape of the sett boundaries, its center part enters the Gonamena sett at the 38 fm level, below which it was extensively developed. Taylor's Lode was explored by short drives from the crosscuts, but was not worked to any great extent.

Between 1848 and 1872, the mine raised 9,985 tons of 6.5% copper ore and 10 tons of black tin, the latter from the upper levels of Sara's Lode. Tin was also mined earlier along the stream on the east side of the ridge, but there are no records of output. The workings consist of surface excavations that are up to 100 yards wide and were 25-30 ft deep. The deposit consists of tourmalinized and chloritized lumps of granite in a matrix of sandy debris representing an eluvial wash derived from Cheesewring and Caradon hills.

The grid reference marks Hingston's Shaft, where a large dump remains besides a stack and traces of an engine house.

Note that the shaft, stack, tips and streaming works are all public access land, however getting there is tricky as everything around is plastered with 'Private. Keep Out' signs and firmly gated and fenced.

Beside the River Smeaton a large tip primarily of crushed quartz and clay 'sand' contains abundant chlorite and chalcocite. A small stream issues from under the tip and may come from the choked entrance to an adit or culvert.

Geochronology

Geologic Time				Rocks, Minerals and Events
Phanerozoic
	Paleozoic
		Permian
			Guadalupian	ⓘ Major polymetallic mineralization ~270 Ma Cornwall, England, UK
			Cisuralian	ⓘ Porphyry dikes intruded (latest age) ~275 Ma Cornwall, England, UK ⓘ Greisenization (latest age) ~280 Ma Cornwall, England, UK ⓘ Porphyry dikes intruded (earliest age) ~280 Ma Cornwall, England, UK ⓘ Formation of metallized pegmatites ~285 Ma Cornwall, England, UK ⓘ Greisenization (earliest age) ~285 Ma Cornwall, England, UK ⓘ Emplacement of major plutons ~295 Ma Cornwall, England, UK

Other Regions, Features and Areas containing this locality

References