Does anyone know how deep the ore body was at Black Thor or Black Label? That may be the key factor in the decision process. If they are looking at a $2 billion investment in infrastructure, they are going to want that back pronto. If they have to dig down an extra 100 meters to do so, that is going to take a lot of time and money.

Since 16 megatons of ore will keep a company digging for at least 20 years, I think it is going to be a question of accessibility rather than 0.6% grade difference...