Initial JORC resource will allow Ardiden to meet one of the key conditions of the development MOU with its Chinese strategic partner; drilling continuing to unlock project's broader potential
Diversified minerals explorer and developer Ardiden Limited (HIGHLIGHTS:
- Maiden JORC compliant Mineral Resource Estimate completed for the North Aubry deposit at Seymour Lake of 1.23Mt at 1.43% Li2O containing 8.2Kt contained lithium.
- The maiden Mineral Resource Estimate comprises:
o Indicated Mineral Resource: 0.44Mt at 1.52% Li2O
o Inferred Mineral Resource: 0.79Mt at 1.38% Li2O
- Lithium mineralisation remains open along strike and at depth.
- Exploration Target established for the Central and South Aubry prospect areas, covering a 1km strike of an interpreted 5km mineralised strike zone.
- Ardiden intends to rapidly advance Seymour Lake towards production
- Test work continuing to develop a suitable processing flowsheet.
The total Mineral Resource estimate comprises 1.23 million tonnes (Mt) at an average grade of 1.43% Lithium Oxide (Li2O) classified as Inferred and Indicated Mineral Resources in accordance with the guidelines of the Australasian Code for the Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC Code, 2012 Edition).
Ardiden CEO and Executive Director Brad Boyle said: "This a great result for the Company, which sets a strong foundation for the fast-track development strategy we are pursuing in conjunction with our Chinese strategic partner Yantai. This marks the first stage of that strategy, and will allow us to meet one of the key conditions precedent under the development MOU signed with Yantai earlier this year."
"It is important to note that the maiden resource covers only a relatively limited strike length of the broader mineralised strike zone at Seymour Lake. It is evident from the drilling data received to date, that the recent drilling has confirmed the geological continuity at North Aubry and, together with the consistency of the lithium grades provide us with an outstanding opportunity to rapidly expand the initial resource."
"Drilling is continuing to test this potential both down-plunge and the long strike at the nearby Aubry prospects. The broader potential of the project is also demonstrated by the initial Exploration Target which has been defined in conjunction with the maiden Mineral Resource estimate over the North, Central and South Aubry prospects."
The Mineral Resource estimate was carried out by independent geological and resource consultants Jorvik Resources Pty Ltd, of Perth, Western Australia (Jorvik).
The classified Mineral Resource is significant first step in the development and the project has real potential for the definition of additional mineral resources along a 5km strike zone.
Using a block model reporting cut-off grade of 0.4% Li2O, which incorporates all internal dilution within the modelled mineralized domains, a total Mineral Resource estimate of 1.23 million tonnes is reported at an average grade of 1.43% Li2O containing 8.2 Kt of lithium.
These results demonstrate the high quality of the North Aubry deposit. With the successful definition of the Mineral Resource estimate and the identification of multiple high grade mineralised zones which outcrop at surface, Ardiden is in a strong position to rapidly advance the North Aubry deposit towards production.
The Company confirms that about 70% of drill assays from the North Aubry drill program were used in the Mineral Resource grade estimation. The mineralised wireframes have been interpreted on the basis of logged geological observations and assay results. Where assays are still outstanding visual estimates of lithium content are applied along with lithology to constrain the mineralised widths of each domain.
During drilling Ardiden found that there was an excellent correlation of assay results to the visual estimates which supported the interpreted wireframes. The areas awaiting results are the northern and southern extents of the model.
Data received to date have revealed the extraordinary geological continuity and consistency of grade within multiple stacked pegmatite sills of the deposit. The Company found the drilling data confirmed the geological continuity and the consistency of the lithium grades across the mineralised footprint at the North Aubry deposit.
The Company intends to update the Mineral Resource once the remaining North Aubry drill assays results are received and analysed in the coming months. These results are expected to infill and confirm the northern and southern extents of the model.
Ardiden confirms the Mineral Resource estimate has been defined within the first 1km of the 5km strike zone, which has not been fully drill tested and remains open at depth and in all directions.
Further, the Company has yet to fully drill test the other key and highly prospective areas lying within the 5km prospective strike length mentioned previously, on the Seymour Lake project, including but not limited to the Central and South Aubry prospects. Ardiden considers that these satellite prospects may encompass additional and substantial high-grade Lithium deposits.
The North Aubry lithium pegmatite deposit comprises one large, main, sub-horizontal dome like pegmatite body, plunging north to north easterly over 225 metres and extending up to 260m down dip to the east. This main body is underlain by two smaller bodies, sub-parallel to the main body (see Figure 1 in the link below) This Mineral Resource estimate contains numerous high-grade lithium zones (6% Li2O) that outcrop. The North Aubry deposit is overlain by a thin horizon of overburden sediments averaging 2 metres thick. The topographic high where the deposit is located, which rises up to 20m above the surrounding plain, host most of the Mineral Resource on the western flank.
The Mineral Resource has a total vertical depth of 100 metres, beginning at the natural surface.
IMMEDIATE DEVELOPMENT STRATEGY
With the successful definition of the initial Mineral Resource estimate at the North Aubry deposit, Ardiden is well positioned and dedicated to the rapid development of the North Aubry deposit towards production.
Ardiden is progressing feasibility work on North Aubry, in order to obtain a better understanding of the economics and potential of the lithium deposit. Once the feasibility work is complete, Ardiden will be better positioned to apply for mining approvals at Seymour Lake and continue to advance off-take discussions with various parties from Europe, Asia and North America.
The Company has already commenced various Feasibility Study activities including bulk sample metallurgical test work and environmental baseline study. Ardiden is currently liaising with a number of specialised mining consultants in order to advance further feasibility work at North Aubry as soon as practicable.
MINERAL RESOURCE ESTIMATION
Geology and Geological Interpretation
The property is located within the Caribou Lake Greenstone Belt, which trends east-northeast along the north shore of Lake Nipigon, extending eastward to the Onamon-Tashota Greenstone Belt in Western Ontario, Canada. Government mapping shows the Seymour claim area as underlain by mostly Willet Assemblage mafic volcanic-dominated rocks, with lesser units of Toronto Assemblage mafic volcanics, and minor Marshall Assemblage dacite tuffs and related sediments. The eastern part of the property is underlain by a tonalite to granite to granodiorite pluton, thought to be the parental intrusion to the rare metal pegmatite dykes and sills exposed at both the North and South Aubry showings. All Assemblages are crosscut by felsic to mafic dykes of various ages and rock types, including the aforementioned pegmatite sills and dykes. The most volumetrically significant post-mineralization intrusive rocks are Proterozoic Nipigon mafic sills, which form the caps of the prominent "mesa-like" hills in the Lake Nipigon area.
Locally, in outcrop and trench exposures the pegmatites are of two general varieties; the first pegmatite is white, and is composed of k-spar, lesser albite, quartz and muscovite and is medium to very coarse grained (megacrystic).
The other pegmatite is orange-red, medium to very coarse grained with k-spar and lesser quartz and muscovite. Both pegmatites can contain spodumene, beryl and tantalite with more secondary hematite alteration noted in the orange variety, which helps imparts its distinct colouration. The bulk of the pegmatites occur as horizontal sills which are often connected by a lesser volume of vertical dikes.
The mafic volcanics are cross cut by at least two generations of shears and/or faults. The main shears dip sub-vertically, and trend north, northeast and east. A prominent set of sub-horizontal step-faults are exposed on a few steep-sided outcrops, and these appear to form the main locus of pegmatite emplacement, especially in proximity to the shears, which also host thin pegmatite dykes. The general broad antiform-synform structure of the pegmatites may be due to dip undulations in the step-faults, or possibility to post-pegmatite folding.
The most prominent alteration found in the mafic volcanics is epidote-calcite-quartz, usually associated with pillowed units which show some degree of strain.
The pegmatites vary in width and are generally comprised quartz-albite- muscovite-spodumene in varying amounts. Late-stage albitisation in the central part of the main outcrop area has resulted in fine- grained, banded, sugary pegmatites with visible fine-grained, disseminated tantalite. A thin hornfels characterised by needle hornblende crystals is often observed in adjacent country rocks to the pegmatite intrusives. Tantalite generally occurs as fine disseminated crystals commonly associated with fine-grained albite zones, or as coarse crystals associated with cleavelandite.
The geological model developed is based on lithological logging of pegmatites within a mafic host, with occasional cross cutting minor pegmatitic dykes.
Drilling Techniques
Drilling supporting the Mineral Resource is diamond core drilling (DD). The North Aubry deposit database includes 124 diamond drill holes for 11,240 of drilling. The Mineral Resource is based on assay data from 87 DD holes for 8,053 metres of drilling.
Drilling has been mostly angled to achieve the most representative intersections through mineralisation, though some historical drilling was vertical. Drilling within the resource area has typically been conducted on a 30m by 30m grid.
Sampling Techniques
Channel sampling assays (historical and Ardiden) were considered for the reporting of the Exploration Target. Sampling was undertaken by Ardiden on known exposures, and through mechanical excavation to expose bedrock immediately beneath the shallow soil cover. Figures 9, 10 and 11 (see the link below) present the georeferenced mapping of the trenches and known exposures.
Historical Drilling prior to Ardiden ownership in Support of Mineral Resource Estimate
DD core was typically sampled on 1m intervals across zones of interpreted mineralisation.
Ardiden drilling in Support of Mineral Resource Estimate
DD core was typically continuously sampled at 1m intervals from the collar to the 10m past the end of mineralisation. Where required by changes in lithology, mineralisation or alteration, core samples may be shorter or longer than the typical 1m. Core was cut into half with one half sent for analysis and the other half stored in the core library at the project site.
Sample Analysis Method
All samples (historical and Ardiden) were analysed by Actlabs in Thunder Bay, Ontario Canada a SCC (Standards Council of Canada) accredited laboratory. The assay technique used for all Ardiden sampling was FUS-Na202 with a 0.01% detection limit. The assay technique is considered to be robust.
Quality control procedures included the insertion of certified standards and blanks into the sample stream. Standards and duplicates were submitted in varying frequency throughout the exploration campaign and internal laboratory standards, duplicates and replicates are used for verification.
Resource Estimation Methodology
Block model construction was completed using 12mE x 12mN x 2mRL size parent blocks, and sub-blocking to a minimum of 3mE x 3mN x 0.5mRL. The parent block size approximates half the average drill spacing in the region of closer spaced drilling (central west) and the minimum sub-block size was chosen to enable accurate representation of the wireframe volumes with the block model. Samples were composited to 1m intervals weighted by bulk density based on assessment of the raw drill hole sample intervals and positive correlation evident between Li2O grades and bulk density. No high-grade cuts were used for Li2O based on statistical review of the composite grade data.
The following linear regression based on Li2O grades and bulk density measurements for 72 core samples of pegmatite was used to calculate bulk density values for all samples prior to compositing.
Bulk Density = 0.0684*Li2O + 2.6626
Li2O grades and the insitu bulk density for the main mineralised zones were interpolated using ordinary kriging. The structural domains of each mineralised zone were estimated separately using soft boundaries between the structural domains. A two-search pass strategy was employed, with successive searches using more relaxed parameters for selection of input composite data, and a greater search radius. Blocks within the southern structural domain of the lower zone and the small mineralised zone located down dip were estimated using the inverse distance cubed algorithm due to the sparsity of data for these domains.
The resource model was validated both visually and statistically prior to final reporting.
Cut-off Grades
The pegmatite wireframes were generated using logged pegmatite lithologies and a minimum downhole width of 2m.
The Mineral Resource is reported using a 0.4% Li2O cut-off which approximates a conservative cut-off grade used for potential open pit mining as determined from preliminary and indicative modelling.
Mineral Resource Classification
The Mineral Resource has been classified in the Indicated and Inferred categories, taking into consideration numerous factors including drill holes spacing, estimation quality statistics (kriging slope of regression), number of informing samples, average distance to informing samples in comparison to the semivariogram model ranges, and overall coherence and continuity of the modelled mineralisation wireframes.
A grade tonnage curve (all classes of resource is presented as Figure 7 in the link below).
Eventual Economic Extraction
The North Aubry pegmatite deposit has not previously been mined for any mineral. Consideration of the results of metallurgical test work, which was announced on 9 February 2017 ("Seymour Lake: Preliminary Test Work Shows Potential to Produce High-Grade Lithium Concentrate Grading Up To 7.73% Li2O"), was given in determining the potential for eventual economic extraction of the estimated resource. The Heavy Liquid Separation (HLS) test work produced lithium concentrate up to 7.73% Li2O with minimal gangue minerals. These results were supported by the ASX announcement on 26 April 2017 ("Seymour Lake: Additional Metallurgical Test Work Confirms Ability to Produce Exceptionally High-Grade Lithium Concentrate"). The second round of HLS test work produced lithium concentrate up to 7.23% Li2O.
The economic potential was supported by ASX announcement on 23 June 2017 ("Seymour Lake: DMS Metallurgical Test Work Continues to Produce High-Grade Lithium Concentrate"). The DMS test work indicates that lithium concentrates of up to 6.43% Li2O can be produced from Dense Media Separation techniques, achieving a recovery of up to 91% at a very coarse crush size of 9.5 mm.
Further, consideration was made with the ASX announcement dated 31 August 2017 ("Flotation Test Work Produces High-Grade Lithium Concentrate"). Test work indicates that lithium concentrates of up to 6.16% Li2O can be produced from a single stage flotation, achieving a recovery of up to 76% at a coarse grind size of 150 microns. Variability test work is currently underway with a range of samples from across the North Aubry resource area, and a suitable processing flowsheet will be developed further for this project.
The North Aubry Mineral Resource daylights at surface and extends to a depth of around 100m below natural surface level. Preliminary and indicative modelling suggests traditional open pit mining methods could be utilised, with the nearby trans-Canada railway providing a suitable transport solution for concentrate exports.
EXPLORATION TARGET FOR NORTH, CENTRAL AND SOUTH AUBRY
Ardiden estimates a combined Exploration Target range of approximately 3Mt to 5Mt at 1.2%Li2O to 1.6%Li2O for the two prospect areas of Central and South Aubry, as well as extensions to North Aubry. The potential quantity and grade is conceptual in nature, and there has been insufficient exploration to estimate a Mineral Resource and that it is uncertain if further exploration will result in the estimation of a Mineral Resource.
The Exploration Target has been reported in accordance with the JORC Code, 2012 Edition on a qualitative basis taking into consideration numerous factors including regional and local context, data support, surface mapping and sampling and historical data. All factors that have been considered have been included in Appendix 1.
The Exploration Target is conceptual in nature and should not be construed as a Mineral Resource that may or may not be defined as a result of further drilling and sampling.
Basis for Exploration Target
Extensive historical data collection, for academic and prospective purposes, has allowed an extensive assessment of the geology of the Seymour Lake project.
In 2002, Linear Resources undertook some surface work, including expansion of pre-existing trenches and lithogeochemical sampling, and drilled 1866 m in 32 holes. This work is publicly available at the website of the Ontario Geologic Survey as AFRI# 52I08NW2004.
In 2008, in an effort to advance the property, 200 metre spaced grid lines at Seymour were refreshed and an Enzyme Leach soil survey undertaken at a 50-metre sample spacing along the lines. At total of approximately 640 samples were collected, which successfully indicated several potential areas of additional pegmatite-hosted lithium-tantalum-beryllium mineralization, both close to the known occurrences and at kilometric distances from them.
In 2009, concurrent with the drilling, Linear crews extended the grid to the south, and mapping, prospecting, lithogeochemical sampling, and extensions to the Enzyme Leach soil survey were completed.
Although the 2009 drilling did not clarify the exact relationship between the Enzyme Leach soil anomaly profiles and patterns to the distribution of pegmatite lenses, the samples do show a very large area of anomalous lithium responses, both close to and at kilometric distances from the known showings, this strongly indicates that there must be additional undiscovered pegmatite sources within the grid area. Several recce lines completed well to the south of the current grid also returned anomalous lithium, and need to be followed up. Till sampling in this area by the OGS also detected strongly anomalous lithium, further supporting the Enzyme Leach soil anomalies.
By combining the 2002 and 2009 sample sets, lithogeochemical sampling of the supracrustal rocks (i.e. mafic volcanic, not pegmatites), both "fresh" and sheared or altered, also indicate at least five significant untested areas of very strong lithium enrichment (complimented by anomalous rubidium and caesium) located immediately SE of the South Aubry showing, where an approximately 200 m long anomaly suggests there are significant extension of the sills in this direction. Furthermore, a third anomaly, approximately 800 m long is located to the west of the South Aubry, suggesting excellent potential for the subsurface extension of the Lower horizon and even the Main horizon if the geometry flexes over to a westward dip.
The Central Aubry prospect is located approximately 500m south of the North Aubry prospect and about 200m north of the South Aubry prospect and is comprised of two main exposures. Ardiden mapping of the Central Aubry prospect shows strong presence of spodumene mineralisation over the majority of the exposures surface.
BASIS OF GRADE AND TONNAGE RANGE DETERMINATION
The assumed average grade ranges (of 1.2% to 1.6% Li2O) of the Exploration Target was largely based on benchmarking the mineral assemblages seen in the surface exposures with those logged during diamond drilling at North Aubry and the results of the Ardiden trenching and rock chip sample program which was last as reported to the ASX on 21 September 2016)
The Exploration Target has been reported in accordance with the JORC Code, 2012 Edition on a qualitative basis and taking into consideration numerous factors including regional and local context, data support, surface mapping and sampling and historical data All factors that have been considered have been included in Appendix 1.
PROPOSED EXPLORATION ACTIVITIES DESIGNED TO TEST VALIDITY OF THE EXPLORATION TARGET
Ardiden is currently designing a further Diamond drill programs over the North, Central and South Aubry prospects that will be undertaken over the next 12 months, to confirm parts of the estimated Exploration Targets. It is anticipated that this drilling will provide the necessary data to estimate a Mineral Resource for parts of these three prospects by late 2018.
CONCLUSIONS
The definition of the maiden Mineral Resource estimate for Lithium at North Aubry demonstrates the true world class potential and the overall prospectivity of the Seymour Lake project, to host both multiple high-grade lithium deposits.
Ardiden now looks to rapidly expand and advance the North Aubry deposit in order to commence lithium production as soon as practicable.
The Company looks forward to providing further updates as they come to hand.
To view tables and figures, please visit:
http://abnnewswire.net/lnk/66A356N9
About Ardiden Ltd
Ardiden Limited (ASX:ADV) is an emerging international diversified exploration and development company possessing a mature multi-element asset portfolio, with a near term development pipeline, focused quality projects located in the established mining jurisdiction of Ontario, Canada.
Contact
Investors:Brad Boyle
Ardiden Ltd
Tel: +61-8-6555-2950
Media:
Nicholas Read
Read Corporate
Mobile: +61-419-929-046
Related Companies
Related Industry Topics: