I had a look at this, and a bit of a play around with the 2D section and lithology. I reckon they're barking 1250m up the wrong tree.
This is only one 2D section, and the orientation of the vertical faults with respect to the section will have a huge impact on the place you go to drill to intersect the prospective basal contact, but the komatiites they have intersected below the thick pegmatite dyke (it's flat, but it's not a sill) are too far east to be directly associated with the Nepean mine sequence. I make this interpretation based on the lack of a flat fault that would offset the sequence at depth to the east.
There are some smaller vertical faults with normal movement (W block down) and others of the opposite throw (E down). These may have strike slip throw associated with them, which could make this a bit more complicated.
In fact, Auroch have put in the listric fault, which offsets the sequence to the east, but not by much (20-60m?), and below the komatiites. There's two thoughts on this.
Number one, that the pegmatite is removing stratigraphy, so the projection is the green line and pink target. The green projection of the Nepean Mine sequence only hits the listric fault deeper to the west. This would be where I would drill the next hole. If it were me, I would drill Hole A, to see if the throw on the western fault could be worked out. If it's minor, it won't matter. But it is critical to know the throw on this fault before attempting a 1400m deep glory hole beneath the thick pegmatite, to target a narrow window above the listric fault. Eg, the projection I made assumes a west-block down throw on this fault and puts the target as predicted. If the throw is opposite, the target will be up.
Number two, that the pegmatite is not removing stratigraphy, and is jacking the stratigraphy apart. The dark blue dip projection and sequence intersected by Auroch, supports this. Which means that the ultramafic sequence is the Nepean Mine sequence, and their test has been successful, via luck or good planning.
However, the listric fault and the normal vertical fault interaction is a bit of an embuggerance. The vertical fault is making a fault window in the plane of the fault, and the listric fault is going to confuse things even further.
At these depths, it's getting very risky to take a punt on the holes missing their targets. The target is the Nepean nickel surface, which is chopped up and faulted apart a lot down here. eg, you can't just cut and paste the whole mine endowment onto the dip surface down here because it's snipped apart by the faults into several smaller fragments. Which makes it...very risky to explore.
I don't know how much shareholder lucre is up to be burned here, but I wouldn't expect these guys to back a rig onto it for a long, long while because it might not be dead, but it's in ICU.
