Drill holes positioning was pre-determined via interpretation on historical drill hole sections and level plans, based on the objectives of adding continuity to the known higher and lower grade gold mineralization at depth and on strike length, and to discover new gold mineralization. Both would have a significant positive impact on the potential of increasing the mineral resources at Douay.
Drilling is done along already established grids on pre-defined drill hole sections, ensuring appropriate drill hole spacing between holes and along parallel sections. Drill holes are positioned in the field following current established standards by azimuth orientation and dip with a hand-held or fixed GPS to ensure precision.
Originally, a single or multi-shot reflex orientation system was used in order to controls drill hole deviation, especially in areas of thicker overburden and magnetic rocks. A gyroscopic instrument is now recording continuous deviation of the drilled hole. Drill holes a few degrees to the left of the intended azimuth to ensure drill holes will follow the intended section.
Prior to and during drilling, the exact position of individual drill holes is verified by the Qualified Geologist in charge of the drill campaign. A down-the-hole deviation test is done once 9 meters has been drilled in bedrock, to ensure the drill hole has not deviated and it remains on course for its intended target depth. Assuming the results of the drill hole do not respect or conform to the technical parameters outlined prior to the drilling, or if the deviation has taken the drill hole outside the normal influence of the vertical section, the drill hole is re-started to ensure the target depth has been reached and explained.
Core boxes are brought to the Aurvista core logging and storage facility at the Douay Camp at the end of each shift by the drill contractor. The Qualified Geologist regularly examine the drill core at the drill rig during the day or night to determine if the proposed target has been intersected. The Qualified Geologist instructs the drillers and/or foreman to either continue the drilling or stop the hole.
At the completion of each drill hole, the overburden drill rods are left in place on instructions from the Qualified Geologist, and a numbered red cap is placed over the protruding drill rod. The numbered cap is usually accompanied by a 1.5-meter-long red metal spike topped by a red metal flag to indicate the location of the drill hole for future surface surveying.
Once core boxes have been received by Aurvista at their core facility, a Qualified Geologist or Technician arranges core boxes on the core facility floor or temporary tables in numeric order from box 1 upwards. Core boxes are then opened and footage blocks are properly checked with the appropriate footages and checked for continuity. The Qualified Technician calculates footages using a measuring tape, making sure the correct footage is written on each footage block, and the end footage for each box is noted on the core box. The Qualified Technician will identify and tag each box with an aluminum metal tag writing the drill hole number and from-to footages, and will measure the Rock Quality Designation or RQD of the drill core and record the rock quality numbers.
The Qualified Technician takes conductivity and magnetic susceptibility or MPP readings directly on the core at 50 centimeter intervals and record the measurements. X-Ray Fluorescence or XRF readings are also taken at 3 meter intervals by taking a 5-centimeter-long piece of core and placing it in the XRF analyser for a reading of the whole rock and trace elements geochemistry to help identify rock types and alteration patterns associated with metallic mineralization,
The Qualified Geologist describe the drill core the GEOTIC Logging system. While describing or logging the drill core, the Qualified Geologist marks for sampling core showing sign of metallic mineralization. The Qualified Geologist marks the drill core with a colored wax pencil (usually in red) the actual intervals to be sampled and these are identified with a perpendicular line at the start and at the end of the intervals.
The Qualified Geologist fill outs (with drill hole number and the from-to intervals for each sampled interval) an ALS Laboratory Group numbered dual sample tags and insert at the end of each interval to be sampled. Samples are taken at 1.5 meter intervals, however sample intervals are adjusted to respect lithological and/or mineralogical contacts and isolate narrow (<1.5m) veins or other structures that may yield higher grades. Once all sample intervals have been chosen, photos of the wet and dry core are taken, usually 4 boxes at a time bounded by a white rectangular legend inscribed with the drill hole number, box numbers, and from’s and to’s.
The Qualified Technician saws the core of the sample intervals in half, cut normal to the predominant foliation and being properly oriented with a cut-line marked by the Qualified Geologist to cut along. One half of the core is kept as a witness sample, the other half is to be analyzed. The half of the dual sample tag for each interval is stapled to the bottom of the core box at the end of each sampled intervals. One half of the sampled intervals is bagged and tagged with one of the dual sample tags from the ALS Laboratory Group. Individual sample bags are sealed and placed into shipping pails and/or nylon shipping bags, sealed and marked with the contents. The samples are delivered by Aurvista personnel in batches sent to the ALS Laboratory Group facility in Val-d’Or, Quebec, for processing, crushing, pulverizing and analysis.
For Quality Control, the Qualified Geologist and Qualified Technician prepare sample duplicates from a quarter split of the half-sampled core inserted approximately at every 20 samples. The method is to split ¼ core of the original sample leaving ½ core remaining as witness in the core box. The results are reconciled with other ½ core samples by averaging the two ¼ field duplicate split results - the average of the two ¼ splits should be the same as a sample of the same ½ core.
A blank sample is inserted every 20 samples – an ideal blank sample usually consists of a granite or gabbro that is known not to contain any metals. Purchased cobbles, barren of mineralization, are also used as blank material. A low-grade rock standard is inserted at every 100 samples. A high-grade rock standard is inserted at every 100. At the end of the analytical process, 5% to 10% of the sample pulps are re-analyzed by a different laboratory for comparative purposes. Multi-element major and trace element geochemistry is done at every 10 samples for rock type identification and alteration vectoring. Specific gravity is calculated in grams per cm3 is also calculated at every 5 or 10 sample intervals.