The NI43-101 only considers narrow veins with a value of $45/tonne when diluted to 1 meter to be within their resource cutoff. What you have brought up may very well be correct and if so it would substantially increase sales and cash flow since 800 tpd could be mined but only the 500 tpd of mineralized ore would need to be processed in the oxide mill. My first guess would be that blasting and jack hammering a 3 foot wide tunnel and seperating the left and right 6 inches from the center 2 feet would be near impossible, but I truly do not know. I bought the 2 volume SME mining handbook a couple of years ago, but only made it to page 150 of 2500 so far.