Ann: High Grade Copper Hits at Forrest and Wodger, page-25

I think it's not the best worded set of sentences ever.

Construction of a longitudinal section involves accumulation of grade x metres and displaying it on a surface (in this case, the contact surface between the Narracoota and Ravelstone). In choosing a VHMS model, the choice is to project the intersections onto the contact surface to represent an accumulation of stratiform or stratabound mineralisation. 

If one interprets this as a structural deposit, that approach is less valid because the mineralisation is not neccessarily controlled by the contact surface. The contours of accumulated grade on the surface aren't representing the correct orientation of metal accumulation.

The best analogy is a shadow puppet. If you project it onto a sheet, it looks like a rabbit. But it's really just a guy's hands and fingers. Or vice versa. 

They have clearly now identified a northerly plunge to these systems as far as i can see. This may have come about by studying the oriented diamond core and measuring vein orientations and projecting it in 3D.