Mineral investigations near Bodmin, Cornwall : part 6, the Belowda area

A series of soil sampling traverses were made across the Belowda Beacon Granite and across slates of the Meadfoot Beds for a distance of 1.7km east of the granite outcrop. These traverses were designed to test the extensions of known and formerly worked mineralisation. In two areas gridded auger sampling was undertaken. All samples were analysed for tin and its common associates, copper, zinc, uranium, arsenic and boron. At the sites of Brynn Tye Mine and Wheal Tregoss, which had been severely disturbed by mining activity, trenching was employed to investigate the geochemistry of the area. The bedrock was examined for tin using a hand-held portable radioisotope fluorescence analyser; significant mineralisation was channel sampled for laboratory assay. The geochemical work revealed anomalous tin values in one of the two gridded areas indicating extensions to two veins which may have been previously worked in a small way. Trenching at Brynn Tye Mine demonstrated that tin mineralisation is associated most commonly with quartz-tourmaline veining and alteration of the slates. Two wide zones of low-grade ore were defined by the sampling, one of which was recognised in two trenches, thus defining a limited strike length. Two inclined diamond drillholes tested the depth continuity of this mineralisation.