Harrow and Hillingdon Geological Society
Rare Minerals in Mexico
Mining for Rare Minerals in Mexico
As Bob Maurer’s talk coincided with the society’s AGM, he delivered a shortened version. It is always difficult to describe Bob’s talks as they are amusing, full of energy and unexpected paths.
Bob took us back to the early 1800’s in the wild American west where prospecting was based on the fables of local Indian tribes. In this case Bob & his team went in search of the ‘Sacred Blue Mountain that was protected by the spirits’. The slides showed an amazing terrain only passable by 4 wheel drive vehicles often at risk to life and limb. Apparently even some of the cacti posed severe and frightening dangers.
These ‘Scared Blue Mountains’ contain deposits of the various oxides and carbonates of copper, zinc, lead some silver and occasionally small amounts of gold. Extraction of these minerals was carried out on a drill and blast basis. As it was difficult for foreigners to get dynamite post 9/11, Bob showed slides of him and his team making their own explosive material. He did warn us not to try this at home
The team collected tellurium minerals from Montezuma, using some very hairy and mining practices in abandoned shafts. From there they went to Zactecas to mine for silver. In Chihuahua, they went to collect from the now famous Oujela mine with its 261 shafts many of which are now abandoned. Here the acidic water, which stripped away many of the minerals notably zinc, was later neutralised by the dolomites and precipitated out the minerals as arsenates.
The most frightening aspect of the whole trip was the lack of any health and safety procedures. The ability to navigate large areas in the dark underground, scale precipitous shafts with huge loads on their backs, balance over seemingly bottomless pits with no safety harnesses and not suffer vertigo were their top priorities.
Bob brought masses of beautiful specimens from a host of different localities for us to examine after the talk. Everyone thoroughly enjoyed his presentation