I believe that 'stacked' mineralized shoots would be the result...

I believe that 'stacked' mineralized shoots would be the result of:
mineralized fluids (carrying gold) travelling along a structure (shearzone, fault etc) depositing gold in the 'nice' layers of black shale. The structures would not necessarily be parallel to the shale bedding.
The shale units would be interbedded layers (variable thickness) of different sediments (variable grainsize and chemistry), e.g sandstone - shale - sandstone
In a higher grade metamorphic terrain (e.g hodgkinson, some vic) this might be quartzite - schist - quartzite etc.

I think the point the RAU geo's make about the stacked lenses, is to investigate black shale layers further down the rythmic sequence of stratigraphy (separated by barren layers). the Geo's would get excited especially where these overall sequences are folded into favourable geometries (much like the folded saddle reefs of vic e.g)
and also where these units are 'cut' by the structure/s which brought in the gold. The folding may be associated with shearing or a separate, later event effectively remobilising any prior mineralisation to e.g 'fold hinges', 'leg reefs' etc.

i have an excellent paper somewhere which i'll try to dig up for a few terrific diagrams which may help illustrate.

sorry cb25, I know two tenths of bugger all about CFIL.
what I will say, is that free milling, coarse gold is the stuff you want. I suspect it can't be all free-milling and coarse if there are periodic gravity recovery issues, given that it's not 'over ground' as described by RAU, using a rod mill.

RAU should implement some security, if this is a deciding factor in recoveries.