Geochemical and geophysical investigations in Exmoor and the Brendon Hills

A programme of geochemical and geophysical study was
started in 1971 to assess the mineral potential of the Exmoor
area. Drainage geochemistry over both Exmoor and
the Brendon Hills indicated areas of anomalous metal
concentrations in stream sediments which call for further
investigation. Some of these anomalies undoubtedly
relate to vein style mineralisation, but others probably
reflect a stratiform distribution of ore metals. Barium
anomalies have also been recognised and these are
presumed to indicate previously unrecorded veins of
barite.
Investigation of an aeromagnetic anomaly which trends
WNW - ESE over the upland areas resolves it into shallow
and deep components. The source of the more deepseated
magnetic anomaly remains uncertain but two diamond
drill holes showed the shallow source to be pyrrhotite
mineralisation in the form of disseminations and
veinlets. Detailed soil geochemistry was carried out over
some of the aeromagnetic anomalies.