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.