Hi Beth. Underground workings are a great boon to the professional geologist. They show 3D exposure and allow the geologist to get a handle on the shape, complexity and structure (limits, joints, faults and their offsets, etc) of the deposit in question.
Normal practice is to survey the workings first; these days with laser-based systems (such as total station) it's a relatively quick process. Modern TS systems now use rotating lasers to capture the workings in 3D and download the data onto cards that can be read later on a PC for transfer into a mining software package or AutoCAD. Geological information can also be surveyed in at the same time as the drive walls, as much of this is vector-based (vein walls, faults, major joints), which gives pinpoint accuracy. Working with surveyor with a TS I've mapped 250m a day in complex geology, so your 7000m should be do-able by two men in around a month.
Once the drives are surveyed they need to be sampled. It is not clear from any data I have seen how much of the 7000m is 'on structure'. My understanding is that these 'Spanish tunnels' were primarily following gold-bearing structures and as such you would need a dense sampling pattern to build up a statistically viable sample base. I would start with a channel sample at every metre; once you had a thousand or so samples you could run geostats to see how well this fits with your sill value (sphere of influence for each sample - hence sample spacing). This may allow you to extend the spacing a little; it's always more difficult to go back and infill rather than extend.
Once you have all the assays fixed by survey points in your 3D map of the workings this data can then be block modelled to give you orebody shapes, tonnages (worked out from sample density measurements)and grades and then fed into a scheduling system to look at extraction methodologies and sequences.
It is difficult to extrapolate how things are likely to progress with ADL/LDM as the paucity of geological information at present does not give any indication of structural continuity in the 'Spanish tunnels' or how they relate to the LDM; my impression is that you are dealing with two separate entities, one a vein system and one a shear (LDM); neither of which are geologically described in any detail or surveyed at present.
The timing of these works will depend on the manpower used, but you're looking at a couple of months at least to complete a survey and sample programme. How long it would take to get these assays back depends on the lab used (I would use ACME in Vancouver or one of the ALS labs). Cost-wise you would need several thousand assays (contingent on mapping results) and the services of a number of consultants with the requisite surveying equipment and software for data capture and block modelling (mining software is very expensive and complex and requires a great deal of expertise to use). It won't be cheap, that's for certain.
