by micropedes1 » Thu Jan 26, 2017 3:03 pm
I am talking about a vuggy quartz stringer with flecks of visible gold interspersed with fist-sized nodules of gold and quartz intermixed. The stringer and fault coincide The surrounding bedrock has visible gold in micro-fractures. Then there is gold disseminated in the surrounding bedrock,; with gold values dropping as distance from the lode increases (as would be expected). The problem is that it lies directly in an active fault. A shear zone, if you would. One side is gold bearing, the other side is devoid of gold.
Yes, I understand blast, muck it out, crush, mill, and separate. But how does one stabilize strata in an active fault zone? Square-set is not much good if one of the walls keeps moving every so often. And it has done it TWICE in the last year. So far, I have been able to mine a limestone reef that intersects the fault, which has been good. There are bits of gold all thru the fractured limestone which indicate that the gold emplacement is a fairly recent geological event. The overburden eroded and the fractured limestone captured much of the gold. But the really good stuff is in the fault.
John, I have no problem drilling and blasting the face. The hanging wall is stable (except when the fault trembles). But one side of the fault keeps shifting; then it rains rocks everywhere. The only thing that I can think of so far is to blast and recover material from one side only. And keep it as a surface mine for as long as possible.