Kirkland Lake Gold Ltd. (TSX:KL) (NYSE:KL) (ASX:KLA) is pleased to report high-grade drill results at depth from drilling at the Robbin’s Hill area along the O’Dwyer’s Trend, a parallel structure to the Fosterville Trend, which hosts Fosterville Mine’s Lower Phoenix and Harrier gold systems (see Figure 1). Recent surface drilling has returned intercepts of visible gold with some of the highest gold grades seen to date from the Robbins Hill area. Mineralization in recent drill core displays similarities to the high-grade, visible-gold hosted quartz veins encountered in the Eagle, Swan and Harrier South zones at Fosterville.
Drill results reported are from 39 surface drill holes totaling 24,985 m that define four mineralized structures in the Robbin’s Hill area along the O’Dwyer’s Trend. Exploration drilling in the Robbins Hill area commenced in August 2016, where drilling has targeted down-dip extensions of mineralized structures mined from open pits in the 1990s. Drill results have demonstrated continuity of grade along four mineralized structures, namely the Curie, Rubin, Franklin and Smith faults and results indicate an increasing grade profile at depth (see Figure 2). Ongoing surface drilling is continuing to test the depth extent of the mineralization, recognizing that the highest-grade mineralization at Fosterville Mine occurs below the 800 m level.
Five holes have returned gold intersections greater than 30-gram metres over a ~350 m strike length from 12450mN and 12800mN and 300 m to 550 m below surface on the Curie Fault. To date, two holes have contained occurrences of visible gold and exploration potential remains open down-dip and along strike. The results from this drill program have been successful in identifying a potentially large auriferous mineralized system displaying width and grade continuity with the potential to yield future Mineral Resources.
Tony Makuch, President and CEO of Kirkland Lake Gold, commented: “We have consistently said that there could be additional Fostervilles on our Fosterville land position, and a sizable portion of our roughly $40 million exploration budget for the area in 2018 is focused on finding the next mining operation. The intersection of high-grade, visible‑gold bearing mineralization at Robbin’s Hill is very encouraging and supports our view that a substantial Mineral Resource and Mineral Reserve expansion opportunity exists within our existing land holdings. Like our current Fosterville Mine, the Robbin’s Hill project area has historic production from abandoned open pits. Recent drilling has targeted the down-dip projections of mineralized structures mined in the pits to depth. The results display marked similarities to the Lower Phoenix system with faults hosting sulfide mineralization enriched with later stage visible gold, quartz-stibnite vein-hosted mineralization at depth. In fact, we have now seen this occurrence towards high-grades with visible gold in quartz veins that intensifies at depth three times; first at Lower Phoenix, then at Harrier and now at Robbin’s Hill, and fully believe there could be more to come.
Extensive exploration drilling is ongoing in the Fosterville area, with a total of 10 surface and underground drills in operation at both in-mine and regional targets. Of planned 2018 exploration expenditures, approximately $30 million is being directed towards the Lower Phoenix, Harrier and Robbin’s Hill systems within the existing mining lease. In addition to Robbin’s Hill, current in-mine drilling is largely focused on Mineral Resource conversion within the Swan Zone, with the Company also having commenced a program of deep drilling to test the down-plunge extension potential of Swan mineralization. Approximately $10 million of planned 2018 exploration expenditures is being directed to the Large Ore Deposit Exploration program, which includes greenfield drilling, surface soil sampling, gravity and 3-D seismic geophysical surveys, and reconnaissance exploration on a number of targets within newly granted exploration licenses.
Robbins Hill Drilling Program
As released in the December 31, 2017 Mineral Resource update (see Technical Report entitled, “Report on the Mineral Resources and Mineral Reserves of the Fosterville Mine in the State of Victoria, Australia” dated April 2, 2018), the Robbin’s Hill Area hosts an Indicated Mineral Sulfide Resource below the 5050mRL of 253 thousand tonnes (“kt”) @ 3.69 g/t Au for 30 thousand ounces (“kozs”) of gold and an Inferred sulfide Mineral Resource of 2,139 kt @ 5.03 g/t Au for 346 kozs. Drilling programs in the Robbin’s Hill area throughout 2016 & 2017 resulted in the addition of 340 kozs of Inferred Mineral Resources below the 5050mRL with drill results defining sizeable extensions of high-grade mineralization that also display indications of an increasing grade profile at depth. Key intercepts that are incorporated in the December 31, 2017 Mineral Resource update are listed below.
Key Gold Intercepts:
ETW – Estimated True Width, all drill results are presented in Table 1 and all drill collars are listed in Table 2.
Drill results returned after the December 31, 2017 Mineral Resource estimates continue to demonstrate extensions of high-grade mineralization including visible-gold mineralization at depth. Results from a total of 7 holes and 5,004.6 m have been returned since the December 31, 2017 Mineral Resource estimate with key intercepts listed below and further details provided in the commentary that follows.
Key Gold Intercepts:
ETW – Estimated True Width, all drill results are presented in Table 1 and all drill collars are listed in Table 2.
(1) – Visible gold intercept
The westerly dipping Curie structure which hosts visible gold mineralization, has now been defined over a strike extent of 700 m and a vertical extent of 600 m (see Figure 3). The occurrences of visible gold have been logged in two holes between approximately 500 – 550 m below surface and the structure is open for expansion down-dip and along strike. Intercepts containing visible gold associated with the Curie structure include 12.9 g/t Au over 3.7 m (ETW 3.2 m) returned in hole RHD282 and 5.1 g/t Au over 3.0 m (ETW 2.9 m) in hole RHD283. The Company is continuing to drill to define down-dip extensions of Curie mineralization with drilling planned on 12500mN and 12700mN below the 4750mRL. In addition, mineral resource definition programs are planned to be undertaken into the Curie structure between the 5000 mRL and 4750 mRL to increase Mineral Resource confidence into an Indicated Mineral Resource classification.
Approximately 150 – 250 m footwall to the Curie structure is the westerly dipping Rubin structure which hosts sulfide gold mineralization over a defined strike extent of approximately 450 m and vertical extent of approximately 400 m (see Figure 4). Recent drill results include 15.0 g/t Au over 0.35 m (ETW 0.35 m) in hole RHD272 and 6.25 g/t Au over 1.2 m (ETW 1.1 m) in hole RHD257. Footwall to the Rubin structure lies a more steeply west-dipping structure named Franklin. The Franklin structure hosts disseminated sulfide mineralization of true widths between 0.5 – 7.0 m and recent drill intercepts through this structure include 3.6 g/t Au over 7.4 m (ETW 7.0 m) in hole RHD259 (see Figure 3). Drill holes targeting the Curie structure during 2018 will be extended to intersect the projected positions of the Rubin and Franklin structures between 12500mN and 12700mN. The current defined extent of mineralization on the Franklin structure is approximately 250 m in strike length and 350 m in vertical height.
A number of east dipping mineralized structures have been defined between the west dipping Curie and Rubin faults, with the most pervasive being the Smith structure, which is interpreted to persist over a strike extent of approximately 700 m and a vertical extent of approximately 150 m. Significant high-grade mineralization is associated with this east dipping structure and recent drill intercepts include 7.7 g/t Au over 9.75 m (ETW 5.5 m) in hole RHD251, and 5.2 g/t Au over 9.0 m (ETW 5.0 m) in hole RHD248 (see Figure 4). The presence of mineralized east dipping faults on the eastern limbs of anticlines is encouraging as analogous mineralized settings exist in the Lower Phoenix system, namely the Eagle and East Dipping structures, which are highly endowed with gold mineralization. Drill targeting of these structures will continue during 2018 to further understand the size and continuity of grade along these structures.
Robbins Hill Geology
Gold mineralization at Fosterville is associated with two main structural trends: The Fosterville and O’Dwyer’s Fault Zones. The O’Dwyer’s Fault Zone, 1.5 km east of the Fosterville Fault, intersects a folded turbidite sequence at Robbin’s Hill.
Robbin’s Hill structural architecture is similar to the Fosterville system, consisting of several folded turbiditic sequences and major NNW trending structures resulting from a WSW-ENE shortening field. A number of major NNW-trending structures have been identified at Robbins Hill, including the recently drilled Curie and Rubin Faults. These reverse faults are post-folding and are interpreted to offset fold hinges at Robbin’s Hill creating ideal structural zones for gold precipitation (see Figure 5).
Major sulfide mineralization is concentrated within regions exhibiting dilatational structures (veins and faults). Sulfide mineralization is dominated by pyrite and arsenopyrite but can include trace occurrences of stibnite, galena, sphalerite and chalcopyrite. Visible gold occurs at depth with observations thus far hosted by the Curie Fault, including several specks <2mm in diameter. Veins hosting the visible gold are dominated by quartz with minor calcite, chlorite, albite, and epidote. Other minerals present that appear to be spatially associated with visible gold mineralization include stibnite and selvedge arsenopyrite / pyrite alteration in the surrounding host rock. Visible gold is typically associated with laminated textures within the vein.
Low-grade sulfide mineralization (~2 g/t Au) is also homogenously distributed within a rhyolitic intrusive dyke seen in the Robbin’s Hill pit, where mineralization is generally vertical and found close to the fold hinge(s). Hydrothermal alteration is abundant within mineralized zones including both sericitic and carbonaceous alteration.
To view a PDF of the figures referenced in this News Release, visit the links below.
Troy Fuller, MAIG, Geology Manager, Fosterville Gold Mine, is a “qualified person” as such term is defined in National Instrument 43-101 and has reviewed and approved the technical information and data included in this News Release.
Drilling and Assay QAQC
Kirkland Lake Gold has in place quality-control systems to ensure best practice in drilling, sampling and analysis of drill core. All diamond drill hole collars (Table 2) are accurately surveyed using a Topcon HiPer SR GPS instrument and down-hole deviations are measured by electronic multi-shot cameras.
Sampling consisted of diamond drill core that was half core sampled. Half core samples were cut longitudinally in half with a diamond saw; one-half of the drill core was sent to an independent laboratory for analysis and the other drill core half retained for reference. Sample pulps are returned from the assay laboratory for reference and future geological or metallurgical studies. Drill core sample intervals vary between 0.3 and 1.2m in length and were determined from logging of sulfide and visible gold to geological boundaries.
Samples containing visible-gold or considered likely to contain visible-gold were separated from sulfide gold samples and dispatched independently for assaying. At the laboratory “visible-gold” jobs were processed through a single pulverizer and material barren of gold (‘quartz wash’) was crushed before and after each sample to minimize the potential for gold to contaminate successive samples.
Assay results are based on 25-gram charge fire assays. Mean grades are calculated using a variable lower grade cut-off (generally 2 g/t Au) and maximum 2m internal dilution. No upper gold grade cut is applied to the data. However, during future Mineral Resource studies the requirement for assay top cutting will be assessed.
Drill samples were assayed at On Site Laboratories, an independent laboratory in Bendigo, Victoria. The facility is registered ISO 9001:2008 (CERT-C33510).
About Kirkland Lake Gold Ltd.
Kirkland Lake Gold Ltd. is a mid-tier gold producer with 2018 production targeted at over 620,000 ounces of gold from mines in Canada and Australia. The production profile of the Company is anchored by two high-grade, low-cost operations, including the Macassa Mine located in Northeastern Ontario and the Fosterville Mine located in the state of Victoria, Australia. Kirkland Lake Gold’s solid base of quality assets is complemented by district scale exploration potential, supported by a strong financial position with extensive management and operational expertise.
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