Authier Lithium Project JORC Mineral Resource Upgrade
- Authier North resource included in new global resource model for Authier
- 88% of the new Mineral Resource in the Measured and Indicated categories
- Potential to expand the resource through further drilling
- Expanded Mineral Resource incorporated into an optimised Pre-Feasibility Study
The expanded, JORC 2012 compliant Mineral Resource estimate has been updated to include the Northern Pegmatite which was not previously incorporated in the Mineral Resource. In addition, the Authier Main pegmatite has been increased due to refinement of the lithium solids model.
The Mineral Resource has been estimated and reported in accordance with the guidelines of the Australasian Code for the Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC Code 2012). A summary of the estimation methodology and competent person statement is included in this announcement.
The Company recently commenced a Phase 3 diamond drilling program with the objectives of collecting up to 5 tonnes of core for a metallurgical testing program, geotechnical, infill and resource expansion objectives.
JORC Mineral Resource Estimate Overview
The Authier project area comprises 20 mineral claims totalling 674.89 hectares, and extends 3.4 kilometres in an east-west, and 3.1 kilometres in a north-south direction, respectively. The mineral claims are located over Crown Lands. The tenure is all in good standing and there is no known impediment to obtaining a licence to operate. The claims are subject to a number of underlying vendor royalties.
The Authier project is situated 45 kilometres north-west of the city of Val d'Or, a major mining service centre, situated in the Province of Quebec. Val d'Or is located approximately 500 kilometres north of Montreal. The project is easily accessed by a rural road network connecting to a national highway a few kilometres east of the project site.
Mineralisation is hosted within spodumene-bearing pegmatite intrusions. The Authier project hosts two separate mineralised pegmatite systems, including:
- Authier Main - 1,100 metres long striking east-west, with an average thickness of 25 metres (ranging from 4 metres to 55 metres), dipping at 40 degrees to the north. The deposit outcrops in the eastern sector and then extends up to 10 metres under cover in the western sector. Drilling in the main Authier pegmatite resource totals 19,513 metres in 137 diamond holes; and
- Authier North - 300 metres long striking east-west, with an average thickness of 7 metres (ranging from 6 metres to 8 metres), dipping at 15 degrees to the north. Drilling in Authier North total 13 holes for 670 metres.
Both Authier and Authier North deposits remain open in all directions. A magnetic geophysical survey has demonstrated that Authier mineralisation is hosted within a strong east-west trending magnetic low anomaly. Future exploration will focus on identifying extensions of know mineralisation within this structural feature.
The lithium mineralisation at the Authier project is related to multiple pulses of spodumene bearing quartz-feldspar pegmatite. Higher lithium grades are related with high concentrations of mid-to-coarse spodumene crystals (up to 4 cm long) in a mid-to-coarse grained pegmatite facies.
The Authier project has been subject to more than 27,000 metres of drilling. The project was initially drilled by Raymor Resources between 1991 and 1999, and then by Glen Eagle between 2010 and 2012. Sayona has completed two phases of drilling totalling 8,084 metres in 49 holes (includes 13 holes for 670 metres at Authier North). Holes were typically drilled perpendicular to the strike of the mineralised pegmatite to provide high confidence in the grade, strike and vertical extensions of the mineralisation.
Prior to Sayona's two drilling programs, NQ size diamond core was halved, 1.5 metre sections were assayed for Li2O content at an ALS laboratory in Vancouver using Inductively Coupled Plasma Mass Spectrometry. Glen Eagle had a rigorous "good industry practise" quality control process, including routine assaying of standards, duplicates and blanks. During the preparation of the Glen Eagle 43-101, SGS recommended that Glen Eagle twin 3 historical drill holes. The program demonstrated strong correlations with historical drill assays.
During Sayona's two diamond drilling programs of 8,084 metres, HQ diameter holes were drilled at near 100% core recovery, and 1.0 metre sections were assayed for Li2O content at an ALS laboratory in Vancouver using Inductively Coupled Plasma Mass Spectrometry. The Company's quality control program included regular assaying of standards, duplicates and blanks. In addition, the program has had oversight of SGS Canada's internal quality controls.
The independent resource estimate was undertaken using reported intercepts calculated using arithmetic averages, no top-cut, and a 0.45% Li2O cut-off grade calculated from the December 2017 Company's Pre-Feasibility Study ("PFS") - see ASX release, "AUTHIER OPTIMISED PRE-FEASIBILITY STUDY DEMONSTRATES EXCELLENT RETURNS - DEFINITIVE FEASIBILITY STUDY UNDERWAY", 11 December 2017.
The PFS has confirmed the technical and financial viability of constructing a simple, low-strip ratio, open-cut mining operation and processing facility producing spodumene concentrate. The Authier deposit will be mined by open cut methods enhanced by the shallow and thick nature of the mineralisation, allowing spodumene ore to be processed from the commencement of mining. The PFS demonstrated a LOM strip ratio of 6.95:1 (waste to ore) providing a low mining cost. The Company believes with further drilling it can expand the size of the resource and provide better definition of the orebody.
A concentrator plant to process 700,000 tpa of ore feed using conventional flotation technology suitable for a pegmatite orebody. The plant will produce a 6% Li20 concentrate suitable for feedstock to lithium carbonate conversion plants.
The resource estimation was based on an Inverse Distance Squared interpolation using Micromine software. The parent block dimensions used were 3 metres x 3 metres x 3 metres with sub-blocks of 1.5 metres x 1.5 metres x 1.5 metres in accordance with the drill spacing and pegmatite body geometry.
The resource has been estimated and reported in accordance with the guidelines of the Australasian Code for the Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC Code 2012). The Global JORC compliant resource estimate at 0.45% Li2O cut-off grade is tabulated (see link below).
Authier Main Deposit
Approximately 98 % of the resource is formed by the Authier Deposit (main Authier pegmatite). On 14 June 2017, an independent JORC Mineral Resource (2012) estimate for the Authier pegmatite deposit was reported. The resource was revised during the preparation of the updated PFS. The lithium mineralization solid was revised and expanded in certain areas.
The remaining 2 % of the global resource is contained within the Authier North pegmatite with the following distribution at a cut-off grade of 0.45 % Li2O.
This updated Mineral Resource forms the basis of an updated Ore Reserve which has been prepared as part of the PFS.
The Measured Mineral Resource was defined within areas of close spaced diamond drilling of less than 35 metres by 35 metres, and where the continuity and predictability of the spodumene bearing pegmatite was high. The Indicated Mineral Resource was assigned to areas where drill hole spacing was less than 60 metres by 60 metres. The Inferred Mineral Resource was assigned to areas where drill hole spacing was greater than 60 metres by 60 metres generally in the edges of the known mineralisation mostly in the down-dip extensions beyond the last drill holes in each section.
The following solid and cross-sections, Figures 3 to 8 (see link below), demonstrate the strong geological and grade continuity of the deposit.
The JORC compliant Mineral Resource estimate is based on 0.45% Li20 cut-off grade. The cutof grade was calculated in the PFS. Figure 6 and Table 3 (see link below) demonstrate the grade and tonnage sensitivity to variation in the cut-off grade. Typically, the tonnage and grade variation is not significant to between 0.3% and 0.6% Li20 cut-off grade estimates, reflecting the low coefficient of variation in the grade of the deposit.
Authier Deposit Optimisation Potential
The Company believes there is further potential to optimise the main resource area including:
- Infill drilling within the main deposit where there is no resource due to lack of drilling density (shown as block circles on Figure 7 in link below), especially in the east and west, and toadd the resource base; and
- Converting inferred resources into a higher resource classifications by further higher density drilling (shown as blue on the diagram).
Authier Project Resource Expansion Potential
The mineralisation in Authier and Authier North remains open in all directions (see Figure 8 in link below). The Company has recently commenced the Phase 3 drilling program with the following objectives:
- Collecting up to 5 tonnes of drill core for a pilot metallurgical testing program. The pilot program data will be used for inputs into the process plant design in the Definitive Feasibility Study ("DFS");
- Infill definition drilling within the main resource zone where the mineralisation is not well defined and is currently treated as waste. This has the potential to reduce the waste to ore ratio;
- Potential expansion of Authier Main pegmatite by testing extensions along strike at shallow levels.
- Potential expansion of the northern pegmatite zone which intersected 7m @ 1.36% Li20 from 15 metres in the last drilling program; and
- Completion of geotechnical drilling. This will enable finalisation of the pit wall slopes for the DFS.
To view tables and figures, please visit:
About Sayona Mining Ltd
Sayona Mining Limited (ASX:SYA) (OTCMKTS:DMNXF) is an Australian-based, ASX-listed (SYA) company focused on sourcing and developing the raw materials required to construct lithium-ion batteries for use in the rapidly growing new and green technology sectors.
The Company's primary focus is the development of the Authier Lithium deposit in Quebec, Canada however exploration for additional lithium deposits is also ongoing in the Authier region and in the Pilbara of Western Australia where the Company has an extensive lithium exploration package of tenements.
Sayona Mining Ltd