Geology description???, page-14

Hi Josh42
there are so many ways to mine narrow vein orebodies. Stoping widths with a long hole rig (accurate drilling) is 1.2m over 10m with minimum ore drive width of 3m with single boom gear and small boggers. There is then air legging that you can get narrower still with reduced production rates.
But yes, UG mining has higher cash costs and could vary anything from $700-$1,300/oz dependant on a number of factors.
You also have to note that grade is king and width doesn't always matter. Take some WA high grade/narrow width ore bodies that are economic. 1.5m wide @ 10g/t. CTO is claiming 27g/t over 0.6m. If say you Dilute to 1.5m using 0.9m @ 1g/t you end up with equivalent 1.5m @ 11.4g/t. As long as the grade is there then width is relative.