Treliver owns a highly prospective package of freehold mineral rights, The Duke of Leeds Estate. These rights contain large parts of the Wheal Vor and Bosworgey districts. Parts of Wheal Vor sit within our ownership – Vor is widely regarded as one of the best tin mines that operated in Cornwall, both in terms of the very high grades and the tonnages. It is reported that between 42,000 and 60,000 tons of tin were produced from the Great Wheal Vor group of mines during the 19th century. Average mined head grade in Wheal Vor is estimated at 3.5% tin with a 1.35% cut-off. The adjacent mine, Wheal Metal, was mined at an average of 5% with an unknown cut-off grade. Several attempts to reopen Wheal Vor between 1851 and 1911 failed – either due to equipment failure or to a lack of capital. The resources identified in the past remain in-situ.
Our work on our rights includes a substantial soil sampling programme and the digitisation of historic mining records into a 3D model. This has identified a number of drill targets – including a previously unmined sulphide zone around a regional fault called the Great Fluccan which crosses perpendicularly to the mineralised lodes. Grab samples of this material have been assayed at 12% Zinc, 6% Copper, 4% Tin, 800ppm Indium, 200 g/t Silver and 0.5 g/t Gold – this is material that was not possible to process in the 19th Century. Many of the lodes in the area have been mined only on one side of the Great Fluccan, usually on the Eastern side only.
The historic data is consistent with a remaining resource of 10 Million tonnes at 1% Sn for 100,000mt contained tin.