RE:RE:OsiskoThere is frequently a low grade zone surrounding the high grade.
On the good side, if the high grade is largely intact, now you can add the crown pillars and any ore next to development tunnels, shafts, etc., to the resources since you no longer need to leave these in place as the pit progresses.
For the open pit, what grades, length of intercepts, metallurgy, etc.? In other words, what tonnage and grade for the open pit, how continuous is the mineralization, strip ratio, etc.? What does it add to the project NPV by having profitable lower grade ore and what capital and operating expense savings are achieved by less underground development work?