Posted by David Bamford on January 06, 2002 at 10:14:24 from 203.201.6.137:
In Reply to: Re: Coniston Copper Mine posted by Mike Field on January 04, 2002 at 13:42:39:
I concur with Mike's assessment! As a retired mine geologist,I would like to warn any member that the investigation of abandoned mines is really frought with danger. The chap walking on the "stemples" is assuming that they are sound and firmly wedged against the rock, and that the rock has not decayed since the opening was made. Timbers in a mine are subject to high humidity, which is very conducive to the formation of various kinds of rot. As slate was mined in the Lake District, this implies a basically weak rock with a strong planar bias. This means that it exfoliates easily. When rock has been removed from an excavation, it is not unusual for the new surfaces to explode violently with the release of lithostatic pressure. This does not necessarily happen straight away, nor does it stop with a single event. Please take care! We don't have so many members that we can afford to lose a few!