On reading the various reports on the Chile Mine rescue of 2010, which occurred at the San Jose copper and gold mine near Copiapo in the Atacama desert of Northern Chile, I was struck by the lack of any reference at all to radon emissions, both in the daily working of the mine, or in reference to the condition or monitoring of the trapped miners. Mention of radon seems to be conspicuously absent from all the accounts I have read online, in books, or various newspaper reports. The published material in particular, appears to be detailed in so many ways, I would have thought some mention of this would have been made at some point, if only to pin point its lack of monitoring, or otherwise, in the working mine or its absence in the workings, - if it was indeed absent.
I have however failed to locate a very detailed geological description of this particular mine and it would be great to see one – even the easily available plans/diagrams of the main workings are woefully inadequate – not a big surprise there, by the way!
The rock which composes the essential structure of the mountain containing the San Jose mine is described as granite in many of the reports and in at least one detailed publication, as diorite – an intrusive igneous rock - often simply described as granite. One other source described the tough rock the drillers had to battle against as a “volcanic
conglomerate with very high silica content”
Would be surprised if the entire hardstone content of the mountain was exclusively one material - but I suppose it can happen.
On the subject of rock identification, I have repeatedly had the various samples of igneous rocks I’ve picked up around Cwmorthin, described to me as “granite” when I'm fairly certain most were not !
(Have the same problem with native American hardstone artefacts – but that's a different story)
'I wonder how many breakfasts, and other meals we have missed inside that nasty clockless, timeless hole?'
'The Hobbit'
J R R Tolkien.