Labs have got back to a more normal 4-8 weeks turnaround for samples received for run of the mill assaying.
Getting the samples to the lab is the same for both RC and aircore.
Diamond core is very different with processing varying depending on requirements/priorities which mean samples take longer to hit the lab after coming out of the ground slower than RC/AC.
Once in the lab a similar process for all sample types depending on assays required.
Dry, crush, pulverise, usually dissolve small portions in acids, assay procedure. Extremely simplified description of sequence, with checks and balances along the way. Results to Client. [Return pulps and coarse rejects to client.]
Client checks QAQC from their own standards/blanks and confirms results are/aren't OK. Crunches the numbers into their database. Run multiple cross checks and then put out an announcement - process takes awhile. Needs to be done well or the ASX will issue a please explain notice. ========================
What will be assayed from the aircore program?I don't know. Many considerations.
My sentinel interp shows approximately 140 sites visited by aircore since early May. Say average of 70m per hole for approximately 10 Kms. The top 20m of every hole is going to be barren (probably) and either not sampled or composited into something other than 1m samples - 4m composites are a common size. The combination of logging and PXRF should enable a good first pass of most prospective zones to be sampled at 1m intervals leaving the remainder to be composited.
Labs do not like oversized samples on a regular basis so 2-5Kg is fairly normal.
Optimistically some 20-30% of holes will need 20-40m zones of 1m sampling.
[Optimistically? Most drill fences extend well beyond the known carbonatite zones and are less likely to contain zones of interest. They might give some surprises. Previous inclined intersections are seldom longer than 40m, usually with a high grade core <10m.]
Sampling all these "interesting" zones at 1m could yield around 2000 samples for assay. Too many? Probably so more selective and/or more composites with follow up 1m as required. Cost, and time, are both factors.
The objective is to provide targets for RC follow up so selected composite samples with only limited 1m detail and/or 4m composites may be the best approach when combined with logging and the "gun". Doing all might be overkill and expensive for little extra benefit.
Only part way through the proposed ~20Km AC program The above estimate suggests 50% of meters drilled though obviously at the highest priority targets (Emily and Crean) at the moment. Perhaps a lower average per hole and/or less holes than interpreted. Hurley RC suggests deeper weathering. All other sites will be first pass reconnaissance aircore. Mawson and Wordie likely to be an "average" profile based on magnetics. The others are commonly mag lows adjacent to outcropping/sub cropping areas so will be interesting to see what depth of cover and weathering.
Multiple regional scale targets to be systematically tested in ~20,000m aircore drill program
Initial drill testing of Green, Joyce, McIlroy and Macklin and follow up drilling to extendmineralisation identified at Hurley, Crean-Hoschke and Emily
Reconnaissance aircore drilling at the Crabeater, Leopard, Mawson and Wordie targets todetermine bedrock geology and establish cover conditions
RC/diamond drilling to follow up areas of significant mineralisation
Representative 1m samples could be stored on or off site for later follow up, A labour intensive process with logistical issues (rarely done?).
The spoil piles used to be left in the field to be spread by nature over the years. Nowadays sites are rehabilitated to remove as much of the disturbance as possible. Holes plugged, sample piles disposed of and the site ripped for easier natural re vegetation. Not something folks of my vintage did until the end of our careers. I was not involved directly in this rehab, by that time, so not something I can really comment on more than the above.
ENR Price at posting:
37.0¢ Sentiment: Hold Disclosure: Held
(20min delay)