Area: 0.87 hectares.
A new site, listed as of national importance in the Geological Conservation Review, under the name of Wheal Penrose. Within and Area of Outstanding Natural Beauty.
Description and Reasons for Notification:
Wheal Penrose is a disused lead mine located 1/2 km south of Porthleven. The existing site comprises extensive mine dumps on which good examples of typical lead zone mineralisation can be found. Secondary minerals include good examples of cerussite, anglesite and lead chloride minerals (pyromorphite, mimetite, laurionite, and phosgenite). The chlorides are believed to have resulted from the action of sea water on the vein, rather than salt spray on dump material. Following the removal/clearance of the Wheal Rose tips, which were once very important for their chloride minerals as well as the rare lead mineral dundasite, the Wheal Penrose mineralogical assemblage has become even more important. It demonstrates the action of saline water on sulphide vein material representative of the lower temperature Hercynian mineralisation.