Pulacayo Project Feasibility Study - Apogee Silver

Pulacayo 1 000 t/d Phase I Feasibility Study - NI 43-101 Technical Report
090644-3-0000-20-IFI-100
10.5 Apogee Drilling Logistics
Planning for drill holes is based on the logging and interpretation of geological cross sections
generated by Apogee staff geologists. Drillhole coordinates are established from digital maps
and surface drill hole collars are located on the ground by field geologists using a hand-held
GPS. Hole azimuth and inclination are established using a compass and clinometer. Collar
coordinates for underground drilling are established by company surveyors and hole azimuth
and inclination are set by transit. Downhole deviation is determined for both surface and
underground holes at approximately 50 m intervals using either Tropari or Reflex down hole
survey tools.
Drill core is initially stored at the drill site in wooden core boxes, which hold approximately
3 m of core. Boxes are marked with the hole identification, box number and the included
depth interval of the hole. Drilling staff mark core depth, generally in 3 m intervals, with a
wooden tag indicating down hole depth at that point in meters. Once the drill hole is
completed, hole collar coordinates are surveyed by staff surveyors and PVC pipe is inserted
into the hole with a portion left exposed approximately 0.5 m above ground to define hole
inclination and azimuth (Figure 10.2) A concrete monument is established around the PVC
pipe and a metal plate is attached that records the company name, hole number, grid easting
and northing coordinates, elevation, final depth and the start and end drilling dates (Figure
10.3).
Overall core recovery reported by Apogee for its programs exceeds 90% in most cases
regardless of the type of rock being recovered. However, proximity to old mine workings
reduces recovery potential due to associated bedrock instability. Mercator staff reviewed core
from various positions within the deposit during the two field visits and confirmed that good
recovery through mineralized zones is generally obtained. However, some intervals of strong
fracturing and reduced core recovery were also inspected.
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