Kirkland Lake Drill Results at Fosterville
Kirkland Lake drills 7.4 m of 976 g/t Au at Fosterville
2020-07-30 15:27 ET - News Release
Mr. Anthony Makuch reports
KIRKLAND LAKE GOLD ANNOUNCES NEW HIGH-GRADE INTERSECTIONS AT FOSTERVILLE SWAN ZONE, DRILLING EXPANDS ROBBIN'S HILL, CYGNET AND HARRIER TARGETS
Kirkland Lake Gold Ltd. has released new high-grade results from surface and underground drilling at the Fosterville mine in Victoria, Australia. Recent infill drilling in the Swan Zone has returned intercepts with higher than anticipated grades and visible-gold near the intersection of the Swan Fault and the Swan Splay structure. Surface drilling has continued to target additional growth in the Robbin's Hill gold system to assess the potential of further Mineral Reserve expansion. Underground growth drilling programs have also progressed in the Lower Phoenix gold system targeting the Cygnet Fault, and in the Harrier gold system targeting the Harrier Base Fault, where encouraging results have been returned. Drill results reported are from 44 holes (6,803 m) from the Swan infill drilling program and 111 holes (59,311 m) from step out, extension and infill drilling at Robbin's Hill, Cygnet and Harrier (Figures 1 & 2).
Infill drilling into the Swan Mineral Reserves intersects higher than expected grades with visible-gold; results highlight potential to add ounces to existing Mineral Reserves
Key intercepts:
976 g/t Au over 7.4 m (ETW 7.0 m);
933 g/t Au over 6.4 m (ETW 5.8 m);
416 g/t Au over 6.8 m (ETW 5.6 m); and
222 g/t Au over 8.1 m (ETW 7.3 m)
Drill results at Robbin's Hill confirm substantial scale of mineralized system; new intercepts identify potential Mineral Resource extensions and new mineralization surrounding the Curie Fault
Key intercepts:
30.8 g/t Au over 3.6 m (ETW 2.9 m) Curie Fault;
10.6 g/t Au over 1.6 m (ETW 1.6 m) Curie Fault;
9.6 g/t Au over 4.6 m (ETW 3.7 m) Curie Fault;
7.7 g/t Au over 3.7 m (ETW 2.8 m) Curie Fault;
5.0 g/t Au over 17.8m (ETW 11.7m) Curie Fault;
68.1 g/t Au(1) over 4.4 m (ETW 3.2 m) Herschel Fault
Visible-gold intercepts in holes RHD413 (Curie) and RHD411A (Curie HW)
Drilling of the Cygnet target demonstrates growth potential outside existing Mineral Resources
Key intercepts:
13.6 g/t Au over 6.6 m (ETW 5.9 m);
12.7g/t Au over 2.1 m (ETW 2.1 m); and
5.4 g/t Au over 9.7 m (ETW 8.0 m)
Drilling of the Harrier target intersects significant mineralization outside existing Mineral Reserves
Key intercepts:
20.9 g/t Au over 5.9 m (ETW 5.5 m);
22.8 g/t Au(1) over 4.3 m (ETW 3.7 m); and
24.5 g/t Au over 3.8 m (ETW 3.8 m)
Tony Makuch, President and CEO of Kirkland Lake Gold, commented: "Drilling at Fosterville continues to demonstrate the significant size and scale of the mineralized structures, all of which contain quartz veining with visible-gold and all of which have the potential to host additional Swan or Swan-like zones. At the Swan Zone, results from new infill drilling include higher than expected grades, which is encouraging as we work towards our next Mineral Reserve and Mineral Resource update. In particular, the infill results confirm that the area where the Swan Fault and Swan Footwall Splay intersect contains more gold than currently modelled.
"At Robbin's Hill, exploration activities are progressing well with recent surface drill results significantly expanding the size of the mineralized system and demonstrating the potential for continued Mineral Resource and Mineral Reserve growth along both the Curie and surrounding mineralized structures. Encouragingly, drilling and recent modelling of newly-acquired 3D seismic data clearly establish the potential for other mineralized structures within the Robbin's Hill area, where there are several historical open pits with plunge extents to be investigated. The new twin underground exploration ramp we are developing will be extremely important for the future exploration of these areas as well as Robbin's Hill itself. The ramp is advancing well, having been driven over 1,330 m to the end of June.
"Drill results at Cygnet and Harrier also continue to return encouraging results. At the Cygnet structure, approximately 125 m footwall to Swan, new drilling returned multiple significant intercepts beyond the northern extent of the existing Mineral Resource. There are several high-grade intersections with visible-gold in the Cygnet system, which extends over a 750 m strike length and 300 m vertically. At Harrier, new drilling returned high-grade mineralization outside of the existing Mineral Reserves, and also demonstrated the continuity of the Harrier structure for an additional 400 metres down-plunge-plunge, with the system remaining open for further expansion. As with Lower Phoenix and Robbin's Hill, the exploration potential at both Cygnet and Harrier is substantial and we are increasingly confident that significant new Mineral Reserves and Mineral Resources can be identified with further drilling."
Exploration activities at Fosterville ceased in late March as part of the Company's COVID-19 response, which included the suspension of all non-essential work. Prior to this time, work on the exploration program was advancing with four surface drills and nine underground drills at Fosterville on the mine lease and three surface drills on regional projects. With the suspension of exploration work, all surface drilling was discontinued and underground drilling was reduced to three drills, all being dedicated to supporting operations and sustaining capital drill requirements. Discussions and proactive planning with drilling contractors were undertaken in early April to manage COVID-19 risks with strict control measures being implemented to support a resumption of exploration drilling. By the middle of the month, two underground drills and two surface drills were deployed. The ramp up of operating drills has continued, with the current fleet standing at four surface drills at Robbin's Hill and six underground drills active at the Fosterville mine. Regional exploration drilling remains suspended as part of the Company's ongoing response to COVID-19.
Swan Infill Drilling Programs
Infill drilling into the Swan Mineral Reserves since the December 2019 Mineral Resource and Reserve update has returned results with higher than expected grades, demonstrating the potential to increase the mine's Mineral Reserves in this zone with further model updates. Intercepts of significant high-grade, visible-gold mineralization of substantial width were returned in a zone where the Swan Footwall Splay intersects the Swan (Figure 3). Two infill holes into this zone returned gram-meter (gold grade x estimated true width) intercepts greater than 5000 gram-m, with a further three intercepts returning greater than 1000 gram-m, with the key intercepts listed below:
976 g/t Au over 7.4 m (ETW 7.0 m) in hole UDH3167, incl. 5,710 g/t Au over 1.3m (ETW 1.2 m);
933 g/t Au over 6.4 m (ETW 5.8 m) in hole UDH3405, incl. 6,202 g/t Au over 1.0 m (ETW 0.9 m);
416 g/t Au over 6.8 m (ETW 5.6 m) in hole UDH3392, incl. 3,510 g/t Au over 0.8 m (ETW 0.7 m);
222 g/t Au over 8.1 m (ETW 7.3 m) in hole UDH3169, incl. 1,684 g/t Au over 1.0 m (ETW 0.9 m); and
156 g/t Au over 9.2 m (ETW 8.6 m) in hole UDH3360, incl. 307 g/t Au over 1.7m (ETW 1.6 m)
These results demonstrate the continuity of extremely high-grade, visible-gold mineralization along the structural intersection of the Swan Fault and Swan Footwall Splay, which plunges gently towards the south. Recent mine development into this zone also confirms the continuity of this mineralization, with this new information expected to result in the addition of new ounces in this area as part of future Mineral Resource model updates. Mine production in the zone of current infill drilling and development is expected to extend through the 2020 {&#A A ; –} 2023 period.
Further infill drilling targeting this intersection area is scheduled for the second half of 2020, which will establish increased drill density and has the potential to support Mineral Reserve growth. In addition, recent drill platform development has been completed and will support continued infill drilling of the down-plunge Swan Inferred Mineral Resources. Drilling using the new platform infrastructure has commenced with three rigs currently in operation.
Robbin's Hill Drilling Programs
The drill results reported were drilled from late Q4 2019 and through the first half of 2020 by up to six surface diamond drills operating in the Robbin's Hill area. The primary target was gold mineralization along the west-dipping Curie Fault, one of the controlling structures for mineralization at Robbins's Hill. Programs have included infill drilling within the existing Mineral Resource, and extension and step out drilling along the Robbin's Hill Curie Fault mineralization trend. Four surface drills are currently operating at Robbins Hill focused on Mineral Resource extension including identifying the potential high-grade shoot down-plunge. Drilling programs in the second half of the year will expand to cover targets generated from the interpretation of 3D seismic data integrated with other geophysical data sets (Figure 4).
Extension Drilling
Twenty-seven surface drill holes for a total of 23,173 m were drilled targeting the down-plunge extensions of existing Mineral Resources and Mineral Reserves on the Curie Fault. The objective of this surface program is to obtain sufficient drill coverage to assess Mineral Resource potential down-plunge southwards to the ~11500mN before the end of 2020. The results of this drilling to date support the potential extension of Curie Fault mineralization approximately 950 m down-plunge from current Mineral Reserves (Figure 5). Additional drilling is required to establish continuity over this 950 m area.
Key sulfide-gold bearing intercepts include:
30.8 g/t Au over 3.6 m (ETW 2.9 m) in hole RHD355;
9.6 g/t Au over 4.6 m (ETW 3.7 m) in hole RHD365;
7.7 g/t Au over 3.7 m (ETW 2.8 m) in hole RHD387B;
10.6 g/t Au over 1.6 m (ETW 1.6 m) in hole RHD374; and
4.9g/t Au over 17.8m (ETW 11.7m) in hole RHD400A
Results down-plunge of the current Mineral Reserves show southerly plunging zones of high-grade gold mineralization within the broader, lower grade mineralized Curie Fault system. The main zone of high-grade mineralization that supported the Robbin's Hill maiden Mineral Reserve is located where the west dipping Curie Fault structure transects and offsets a felsic dyke that has intruded along an anticlinal fold axis. Other zones of dilation and high-grade mineralization are emerging along the Curie Fault as it transects the folded sequence, as represented by a grouping of higher-grade results including RHD408 and RHD387B (Figure 5). These zones are typically represented by zones of extensional veining and disseminated sulfide gold mineralization, but often have stibnite-enriched quartz veins indicating a high potential for visible-gold mineralization.
Two recent diamond drill holes in RHD413 and RHD411A have intersected visible-gold mineralization at depth as part of this program, further reinforcing the growth potential in this area.
RHD413 intersects the Curie Fault approximately 950 m down-plunge from Mineral Reserves where the hole transects the eastern limb of an anticline. The structure hosts a 0.6 m wide brecciated to massive quartz vein containing 2-3mm slugs and specs of visible-gold which run parallel to a stylolite approximately 50 mm from the lower vein contact. The vein is surrounded by disseminated sulfide mineralization and tension veining, which is more prevalent in the sandstone dominated footwall, extending for approximately 2 m from the vein. This visible-gold occurrence is the deepest and southernmost observed occurrence on the Curie Fault to date (Figure 5).
Further to this, visible-gold mineralization has been intersected in other structures adjacent to the Curie Fault. RHD411A intercepted two westerly dipping quartz veins of 150-200 mm thickness approximately 60 m hangingwall of the Curie Fault (Figure 5). The two veins contain strong laminations and stylolitic textures, the lower of which contained a spec of visible-gold. Disseminated stockwork veining and sulfide mineralization, whilst relatively constrained on the hangingwall, extends at least 3 m into the footwall of the structure.
A significant part of the planned drill programs at Robbin's Hill for the remainder of 2020 will aim to further define the continuity and extent of these high-grade mineralized shoots down-plunge, which are open for expansion at depth.
In addition to results returned from the continued expansion drilling targeting the Curie Fault at Robbin's Hill, a significant intercept containing visible-gold on the adjacent Herschel Fault was returned. Hole RHD408 contained an approximate 100 mm wide quartz interval containing a quartz vein bearing visible-gold and stylolitic textures surrounded by a halo of disseminated sulfide mineralization with an estimated true width of 3.2 m.
Key visible-gold bearing intercept:
68.1 g/t Au over 4.4 m (ETW 3.2 m) in hole RHD408, incl. 747 g/t Au over 0.35 m (ETW 0.3m)
The Herschel Fault occurs approximately 200 m hangingwall to the Curie Fault at the northing of intersection (Figure 6) Surface drilling targeting Curie has incidentally intersected the Herschel Fault through recent drill programs. Initial interpretations suggest that mineralization is orientated on the north-south trending west-dipping fault and requires further drilling to determine its strike, dip and down-plunge lengths. There is potential connectivity with mineralization associated with the Robbin's Hill pit towards the north, which also has occurrences of visible-gold mineralization, However, further drilling and interpretation work is required to confirm this. The intercept for RHD408 demonstrates the potential for high-grade visible-gold mineralization along the structure, and vectoring in on its location and determining its extent will form part of future drill programs in the Robbin's Hill area.
Step out drilling
Six step-out drill holes, totaling 7,343m demonstrate that mineralization on the Curie Fault persists over a 2 km distance to the south of the existing Robbins Hill Mineral Reserves (Figure 5). Intercepts from this drilling demonstrate the scale and growth potential of the Robbin's Hill mineralized system which has the potential to similar in size and scale to the Phoenix system (approximately 3.5 km in strike length) at Fosterville. Drill holes RHD395, RHD376 and RHD379 targeted the Curie Fault beyond 1.5 km to the south of Mineral Resources, and each hole intersected significant quartz-dominant stockwork disseminated sulfide mineralization. The intercepts for RHD395 and RHD376 were characterized by increased sulfide mineralization at a fault in an oblique-oblique structural setting on the eastern limb of a parasitic anticlinal fold. Drill hole RHD379 intersected the Curie Fault, adjacent to an up-dip syncline axial plane, with east dipping mineralized structures also identified in the hanging-wall (Figure 5).
The most southern sulfide-gold bearing intercepts include:
2.9 g/t Au over 2.6 m (ETW 2.0 m) in hole RHD395;
2.5 g/t Au over 5.3 m (ETW 4.6 m) in hole RHD376; and
1.8 g/t Au over 7.9 m (ETW 7.6 m) in hole RHD379
The demonstrated extent and scale of the system highlights the opportunity through further drilling to realize substantial Mineral Resource growth.
High-Resolution 3D Seismic Survey
The Company completed a high-resolution 3D Seismic survey in the northern part of the Fosterville Mining License over the Robbin's Hill mineralization trend. The survey was the first of its kind to be undertaken in Victoria for gold exploration and provides a high-resolution 3D dataset to a depth of over 1 km for detailed planning of future of underground development.
The survey area was approximately 6 km2 with data collected along 12.5 m spaced east-west lines (Figure 4). Initial processing of the 3D seismic data was completed in April with fold resolution defined to 30 m and significant structural trends identified. Interpretation of this data is underway and combined with other geophysical datasets target generation work is progressing. The seismic data will contribute to the geological understanding and aid future exploration and development of the Robbin's Hill area.
Robbin's Hill Underground Decline Development
Underground development of the Robbin's Hill ramp commenced in January this year and has progressed ahead of schedule, advancing a total of 1,336 m to the end of June. The recent arrival of a smart jumbo will provide increased development capacity and we will be targeting a total of 3,380 m of development at Robbin's Hill in 2020. The development will be used as an underground drill platform for exploration diamond drilling activities as the ramp progresses.
Cygnet Drilling Programs
Recent drilling exploring the northern extensions of the Cygnet Mineral Resources have returned encouraging results with three returning intercepts greater than 30 gram-meters (Figure 7). The Cygnet Fault key intercepts include:
13.6 g/t Au over 6.6 m (ETW 5.9 m) in hole UDH3398;
10.8 g/t Au over 2.9 m (ETW 2.9 m) in hole UDH3207A; and
5.4 g/t Au over 9.7 m (ETW 8.0 m) in hole UDH3206
These results demonstrate the potential for further expansion of Cygnet Mineral Resources to the north and exploration drill programs during the second half of 2020 will initially target up to 250 m beyond existing Mineral Resources.
In addition, infill drill results into the Cygnet Mineral Resources continue to return encouraging results and both Cygnet and subsidiary structures Cygnet Hangingwall and Footwall Splays contain significant mineralization(Figure 7 & 8) including key intercepts:
Cygnet Infill
12.7 g/t Au over 2.1 m (ETW 2.1 m) in hole UDH3196;
11.0 g/t Au over 8.5 m (ETW 5.7 m) in hole UDH3492;
8.1 g/t Au over 4.9 (ETW 4.2 m) in hole UDH3485;
9.4 g/t Au over 3.1 m (ETW 2.0 m) in hole UDH3417A; and
6.1 g/t Au over 6.0 m (ETW 5.6m) in hole UDE279
Cygnet Splays
36.6 g/t Au over 2.2 m (ETW 1.9 m) in hole UDH3492, incl. 168 g/t Au over 0.4 m (ETW 0.3 m); and
4.2 g/t Au over 4.3 m (ETW 4.1 m) in hole UDH3206
Infill drill programs into Cygnet will continue throughout the second half of 2020, with the objective to increase resource confidence to enable mineral reserve evaluation in this zone at the end of the year.
Harrier Drilling Programs
Recent drilling exploring the down dip and southern extensions of the Harrier Base Fault have returned encouraging results, demonstrating continued growth opportunity in the Harrier system.
High-grade sulfide mineralization has been intersected on the Harrier Base Fault between the 4150 and 4250mRLs (Figure 9), displaying grades and widths with significant potential to support further Mineral Reserve expansion in this zone. The Harrier Base Fault key intercepts outside of December 2019 Mineral Reserves include:
20.9 g/t Au over 5.9 m (ETW 5.5 m) in hole UDH3045 incl. 295 g/t Au over 0.3 m (ETW 0.3 m);
22.8 g/t Au(1) over 4.3 m (ETW 3.7 m) in hole UDH3474A;
24.5 g/t Au over 3.8 m (ETW 3.8 m) in hole UDH3497;
12.0 g/t Au over 3.8 m (ETW 3.7 m) in hole UDH3498;
8.3 g/t Au over 9.4 m (ETW 9.3 m) in hole UDH3510; and
5.2 g/t Au over 6.9 m (ETW 6.8 m) in hole UDH3499
In addition, drilling targeting the Harrier Base Fault down-plunge demonstrates that continuity of mineralization extends a distance of approximately 400 m down-plunge of the lowest Mineral Reserves and is open for further exploration targeting. Mineralization grades and widths of significance occur along this plunge extent and include:
8.1 g/t Au over 4.5 m (ETW 3.9 m) in hole UDE239;
Further to this, drilling extended below the Harrier Base fault has outlined the stratigraphic and structural framework to assist with further target generation in the Harrier zone (Figure 10). Structures footwall to the Harrier Base have displayed evidence of sulfide mineralization (Wagtail) and present future targets at depth.
The Harrier gold system has now been defined over a down-plunge extent of approximately 3.4 km and remains open for expansion. Future drilling in the Harrier zone will test target strike and dip extensions of known mineralized structures such as the Harrier Base Fault as well as adjacent trends of known and interpreted mineralization.
Qualified Persons
Troy Fuller, MAIG, Director of Exploration, Australia, 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.
For further information regarding the Company's 2019 Mineral Reserves and Mineral Resources estimates for the Fosterville Gold Mine, please refer to the Company's News Release dated February 29, 2020 and the Technical Report entitled "Updated NI 43-101 Technical Report Fosterville Gold Mine In the State of Victoria, Australia" effective December 31, 2018.
Drilling and Underground Sampling 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 Leica TS16 Total Station instrument and down-hole deviations are measured by either electronic gyro or single-shot instruments.
Sampling consisted of diamond drill core that was either full core (i.e. for Swan drill samples) or 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.
Assays are either based on 25-gram fire assay. Mean grades are calculated using a variable lower grade cut-off (generally 2 g/t Au) and maximum 2 m 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.
The samples were assayed at On Site Laboratory Services, an independent laboratory in Bendigo, Victoria. The facility is registered under ISO 9001:2015 (CERT-40147) and operates in accordance with ISO/IEC17025 (accreditation no. 20456) under National Association of Testing Authorities, Australia (NATA).
About Kirkland Lake Gold Ltd.
Kirkland Lake Gold Ltd. is a growing gold producer operating in Canada and Australia that produced 974,615 ounces in 2019. The production profile of the Company is anchored by three high-quality operations, including the Macassa Mine and Detour Lake Mine, both located in Northern 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 expertise.