Tin and copper have been mined in Cornwall for at least a thousand years and relic mine workings are in evidence throughout the county. Particular attention has been paid to the likelihood of their presence at the modern Wheal Jane Mine, lying as it does in the Chacewater area where mining was extensive in the 18th and 19th centuries.
The main photograph shows part of the hanging wall of an old stope, originally uncovered by excavation on the east bank of the Clemows Valley tailings dam in 1977 and subsequently re-excavated in 1982.
Figure 1 shows the location of these workings within the confines of the tailings dam. The stope was discovered when investigation of a small adit-like opening revealed extensive workings of unknown depth, partially backfilled with loose rubble but with some arch pillars still intact. The stope appeared to have been commenced from surface, becoming progressively deeper into the valley side; in the location shown it lay about 6 m below ground level (Fig. 2). The stope was approximately 1 m wide with a dip of about 70° to the north, and it appeared to lie on the same structure as the hot lode, a parallel feature uncovered in 1974 on the west bank of the dam.
The country rock in the Wheal Jane area comprises Devonian killas of the Mylor series, a generally blue-grey, weakly metamorphosed pelitic rock with extensive quartz veining, which weathers to a buff to red clay slate. Figure 2 gives some indication of
- © The Geological Society 1985