The Vickers Zone is located in the northwest-trending Pistol Bay Corridor in the central part of the Property. The Vickers Zone host rocks are a sequence of quartz-sericite-carbonate schists and proto-mylonites. The schistose rocks at Vickers are locally known as “pipeline rocks” due to their pronounced, penetrative, schistosity reaching proto-mylonite, and extreme secondary sericite and carbonate alteration. The pipeline rocks define the Pistol Bay Corridor. Due to of the fabric and secondary hydrothermal alteration superimposed on the pipeline rocks, it is difficult to ascertain their protolith(s), however, they are derived from a parent rock of felsic composition, and are possibly part of a felsic volcanic or volcaniclastic sequence derived from rhyolite, rhyolitic pyroclastic rocks, and quartz-feldspar porphyries.
The mineralized zone at Vickers is along the contact of a diorite intrusion (Figure 7-4). The nature of the intrusion is difficult to define because there are no unaltered primary rocks. Secondary, chlorite, white mica, rutile, and carbonate are ubiquitous and in thin section, the plagioclase grains have mortar texture caused by extreme strain. The least altered rocks in the western part of the intrusion have retained some remnant magnetism and nominally have a relict igneous texture with plagioclase grains surrounded by a matrix of chlorite and rutile pseudomorphs presumably after clinopyroxene. In addition, there are abundant dikes and pipe-like bodies varying in composition from quartz diorite to granite.
The contact of the intrusion with the pipeline rocks trends approximately 295° and dips approximately 60° to 70° to the south. The intrusion is elliptical and approximately one kilometre in length, based on mapped contacts with the surrounding rocks, which are mature quartz arenite. On the east contact of the intrusion, the quartz arenite sequence is a mature, cross-bedded sequence of highly variable attitude caused by complex folding. Bedding of the quartz arenite sometimes dip north and away from the intrusion, i.e. the opposite dip of the intrusion and footwall contact. Bedding of the quartz arenite is commonly in the opposite direction of the schistose, planar fabric of the intrusion and footwall contact and there are no known intrusions of gabbro or diorite in the quartz arenite.
The Vickers intrusion is a magnetic anomaly with two parts; i) a moderate magnetic anomaly in the west part of the intrusion, which is remnantly magnetic presumably because there is minor primary, disseminated magnetite, and ii) no magnetic anomaly in the east part of the intrusion which is demagnetized by magnetite-destructive hydrothermal alteration attendant with the gold concentration. The east part of the intrusion has the same magnetic intensity as the surrounding rocks, and because of this, and the relationship of the Hurwitz cover sequence, we do not currently know the location and nature of the east contact of the intrusion.
In August, 2013, an induced polarization (IP) and resistivity survey was completed on a 16.3 line-kilometre grid covering the mineralized zone in the east part of the intrusion and an area to the east to determine what, if any, IP and resistivity anomaly is associated with the gold bearing rocks. A very clearly defined and strong IP anomaly starts at about 8950 W and is coincident with gold-bearing drilling intersections from that section to the east at least as far as section 8800 W, where our easternmost drill hole is located. East of section 8800 W, the IP anomaly continues for at least another 200 metres, which is the limit of the current IP survey area, and in that area the anomaly is concealed by the Hurwitz Group. Another strong IP anomaly on the east edge of the grid, 150 metres east of the V2 Zone, is concealed by the Hurwitz Group and untested by drilling. The resistivity survey highlights the resistive quartz arenites of the Hurwitz Group and does not provide much definition of the variably resistive gold bearing rocks.
The Vickers Target had previously been tested by Canico, and is the Pistol Bay target that to date has received the most exploration attention by Northquest. A total of 69 drill holes totalling 17,240 m have been drilled at the Vickers Zone.
Drilling at the Vickers Zone to date has been completed mostly at an average drill hole spacing of 50 m to 100 m. Mineralization remains open in all directions, particularly to the south, however, grade and thickness of mineralization appear to taper to the east. There is some potential for increases in the Vickers Zone Mineral Resource, however, RPA concurs with Northquest’s focus on exploring the other prospective targets identified on the Property.
In 2012, Northquest twinned specific Canico holes. The comparisons are not entirely consistent; however, they do show that the grades and lengths of the 2012 Northquest drill holes are typically higher (Gow, 2012).
In 2012 a minor amount of reconnaissance work was completed and 22 holes were drilled comprising 4,580 metres of which 14 drill holes (3,600 metres) were completed at the Vickers Target.
In 2013, ten drill holes (2,016 metres) were completed at the Vickers Target and IP/resistivity surveys were completed on a small geophysical grid. The best drilling results were from PB-13-06 of 138.39 metres grading 3.79 ppm gold. The drilling results from the Vickers gold zone in 2013 combined with the results from 2012 clearly indicated that gold mineralization was continuous in three dimensions at economically interesting grades and that additional drilling was warranted.
In 2014, the Company completed 18 drill holes (4,550 metres) of drilling at Pistol Bay. Thirteen drill holes (3,785.10 metres) were completed at the Vickers gold zone, 3 drill holes (474.30 metres) were completed at the Sako gold occurrence, and 2 drill holes (295 metres) were completed at the Bazooka gold occurrence. The known strike length of the Vickers gold zone was increased to 400 metres and the best drilling results were 221.74 metres grading 1.65 ppm gold in drill hole PB-14-08. Detailed mapping and rock sampling was also carried out at the Vickers gold zone as well as reconnaissance prospecting and mapping on the entire property.
In 2015, 32 drill holes (7,838.20 metres) were completed at the Vickers gold zone and two drill holes (294.50 metres) were completed at the Defender gold occurrence. The known strike length of the Vickers gold zone was extended to a total of 700 metres. The best drilling intersections were 39.00 metres grading 2.57 ppm gold in PB-15-20 in the eastern extension of the main Vickers gold zone and 19.00 metres grading 2.22 ppm gold from a newly discovered intrusion the “Eastern Porphyry” that is interpreted as a felsic phase of the Vickers intrusion.
The total amount of drilling at the Vickers Zone to the end of 2015 was approx. 17,195 metres in 69 drill holes and the total amount of drilling at the Pistol Bay to the end of 2015 is 21,750 metres of drilling in 100 drill holes.
The drilling results is listed in the following table.
Summary of weighted average grade of gold in all of the drill holes from the Vickers Target to date, completed in 2012, 2013, 2014 and 2015, including all continuous intervals of variable average grade.
|Hole||Section (m)||Length (m)||Azimuth||Collar Inclination||From (m)|| To (m) ||Intersection Length (m)||Au (g/t)|
Note: Intersection lengths are core lengths and do not necessarily represent the true width of the mineralized zone. Weighted average grades are calculated from assays of drill core with nominal sample lengths of 1.0 metres. The detection limit of the assay method is 0.01 to 0.05 ppm gold. Some of the samples within the intersected lengths reported in the table are below the detection limit and the assay value for those samples used in the weighted average grade calculation is zero.
Gold occurrences and magnetic anomalies (TMI) of the Pistol Bay Project
Vickers Gold Zone - IP Chargeability
Vickers Gold Zone - IP Resistivity
Vickers Gold Zone - Geology and Drilling
Selected Images from RPA 2016 Resource Estimate
Vickers Zone Geologic Model in Section
Vickers Zone Mineralization Domains
Vickers Zone Mineralization Domains in Section
Vickers Zone Block Model with Whittle Shell