A gold miner has died in an accident at the Small Mine Development operated Lee Smith Mine in Jerritt Canyon in Elko County, Nevada, on Thursday 25 October 2018. Jason Holman, 42, of Goshen, Utah, was loading blast holes (setting explosives) when the roof of the chamber he was in collapsed upon him. This is the first fatality at a Nevada mine since October 2017.
The approximate location of the Lee Smith Mine. Google Maps.
The Lee Smith Mine accesses gold deposits within the Hansen Creek Formation and the base of the Roberts Mountains Formation, part of the Roberts Mountains Thrust Complex. These deposits are angled at about 30° to the horizontal, as a result of the thrusting which generated the energy which liquefied then gold-hosting deposits, resulting in then becoming concentrated enough to be worth mining commercially. Because of the steeply sloping nature of these deposits, they are accessed using a cut-and-fill method, that involved tunnelling down to a deep part of the target formation, excavating a section there, then infilling this and removing the material above through a succession of shallower tunnels, a method which on this occasion appears to have undermined the deposits above the active mining area.
Diagrammatic illustration of a cut-and-fill mine. Note that the active mining is occurring above filling material. Queen's University/Mine Wiki.
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