Embracing the cyclical nature of the mining sector
Projects & Royalties
2.5 % NSR
LGN Holdings (BVI) Inc.
Shear-hosted gold (Birimian greenstone belts)
Within the same belt as the 7.0 Moz Morila Au mine
0.91 Moz Au (Ind+Inf)
Next Phase of Work:
Marvel Gold Limited (ASX:MVL)
US$1.45M in milestone payments + 2.5 % NSR
The 100km2 Tabakorole Project is situated in South Western Mali, 280km from Bamako and 17km South of the village of Garalo. Tabakorole hosts a resource (calculated at a 0.6g/t Au cut off grade) of 910,000 ounces contained Au for 1.2 g/t Au, comprised 290,000 ounces at 1.2g/t Au in the 'indicated' category and 620,000 ounces at 1.2g/t Au in the 'inferred' category from the oxide and fresh zones (Table 1). The mineral resource estimate was prepared in accordance with the JORC Code and was commissioned by the Company's joint venture partner, Marvel Gold Limited (https://marvelgold.com.au/) and reported as at 30th September 2020. Drilling results include 44m @ 3.29g/t Au and 16m at 9.31g/t Au (Table 2). The FT Prospect remains open along strike and down dip.
A number of targets have been defined for follow up exploration with potential for resource expansion, notably recent air-core (‘’AC’’) and diamond (‘’DD’’) drilling has confirmed that gold mineralisation continues at least 600m to the north-west along strike of the FT Prospect, which remains open along strike and at depth. There are also areas throughout the existing resource that are constrained due to a lack of drilling data.
Additional targets include the 2.5km long FT South target, a geophysical anomaly sub-parallel to the FT prospect historic resource, and the FT East target, defined by a 2.6km long gold in soil anomaly. Drilling undertaken after the historic resource in 2010, 2011 and 2014 returned results including 18m@ 6.05g/t Au and 24 m at 2.53 g/t Au were not followed up by the previous operator.
The shear zone, up to 200m wide, is part of the Massagui Belt which hosts Barrick Gold's (NYSE : GOLD) Morila gold mine (6.0Moz Au).
Table 1: Tabakarole project JORC compliant mineral resource (2020)
Grade (g/t Au)
Metal (Oz Au)
Table 2: Selected Tabakorole drill intersections
Grade (g/t Au)
Intersections based on 0.5g/t Au cut off and ⩽ 2m non-cumulative internal waste
A major Au soil anomaly was delineated from results of a regional soil sampling programme with grid spacing of 500m x 100m following initial discover by BHP in the early 1990s during a regional soil sampling programme. Since 2003, 28,912m of diamond, 31,943m of RC, 6,577m of auger and 60,676m of air core drilling have been completed along with 1,400km of airborne geophysics.
In 2014, Legend completed a 741 m infill RC drilling programme. The 14 drill holes were positioned to provide intersections in oxide mineralisation in areas where sulfide grades had been extrapolated into the oxide zone. The drilling confirmed continuity and grade of oxide mineralization of the FT deposit. Later in 2014 a detailed and infill termite mound sampling programme on an area of approximately 3km by 2km on the Npanyala exploration permit was also completed.
During 2020, under joint venture, 520 line kilometres of ground magnetics have been completed, covering the north of the licence with 9 priority magnetic anomalies identified with a combined strike length of over 8km. 2,042m of AC drilling were completed in Q2 2020 with down the hole intercepts including 1.05g/t Au over 12m from 9m, 0.77g/t Au over 21m from surface and 6.2g/t Au over 6m from 14m depth defining a 600m northwest extension to the FT Prospect. Results from an eight-hole, 1,544m, diamond drill programme, completed in August 2020 focussed on infill drilling along the FT Prospect, with down the results returning 4.7g/t Au over 14m and 1.2g/t Au over 31m.
Next stages will include joint venture funded preliminary metallurgical testwork.
Mineral Resource Estimate
International Resource Solutions Pty Ltd of Perth, Australia, prepared the MRE in accordance with JORC Code as detailed in Table 2 below.
Table 2: Tabakorole Mineral Resource Grade-Tonnage
Cutoff (Au g/t)
Multiple Indicator Kriging (“MIK”) with change of support was selected as the most appropriate method for estimating the gold resource contained in the Tabakorole deposit. A total of two grade estimate domains have been developed within the mineralised zones and based on the geological description in the previous sections and an approximate lower cut-off grade of 0.3 g/t gold.
A block size of 20mE x 25mN x 10mRL was selected as an appropriate block size for estimation based on the drill spacing (50m strike spacing or better), the geometry of mineralisation and the likely potential future selective mining unit (SMU) (appropriate for potential open-pit mining). An SMU dimension of 5mE x 12.5mN x 5mRL was selected as appropriate for support correction investigation. An indirect lognormal support correction was applied to emulate mining selectivity for the above SMU dimension.
The MIK grade estimates consist of a series of proportions and grades above the pre-defined cut-off grades estimated into a ‘panel’ or large blocks. The proportions and grades are derived from a targeted SMU block size via change of support process. As such, while the proportions and grades at a certain cut-off for any given panel may be known, its position within the panel is not. To assist with a more intuitive presentation of the model grades, the MIK grade estimates have been localised to SMU dimension blocks using a process identical to that of Localised Uniform Conditioning. The SMU sized blocks have been assigned a single grade so that the panel MIK grade estimate grade tonnage curve has been replicated.
Raw sample intervals from the drill hole database were flagged by the estimation domains and composited to 2m downhole intervals for the purposes of equalising sample support and as an input to grade estimation.
The impact of higher-grade gold outliers was examined on composite data using log probability plots and cumulative statistics. This is particularly relevant in the case where extreme grade values may exist however MIK estimation as implemented at Tabakorole is independent of top cutting and was therefore not applied to the final grade estimate.
Grade and indicator variography were developed based on the downhole composites. Indicator variography was input to the MIK estimates while grade variography was used for the change of support analysis applied to the MIK estimates.
The proposed development scenario for the deposit is as an open cut (pit) mine. No additional mining dilution has been applied to the reported MRE.
Very limited metallurgical test work has been done and this was only completed on oxide material. The test work was carried out by Peacocke and Simpson in Zimbabwe in October 2015 on a 100kg sample collected using auger drilling over an area of 20 x 25m centred around hole 06TKDDH-059. The process yielded a total of 90.6% recovery using a conventional cyanidation process. Due to the limited coverage and selective nature of sampling the results from this test work are not considered representative of the deposit. Marvel has advised the Company that it plans to complete a preliminary program of metallurgical test work using material collected from drill core in the future. No other additional modifying factors have been considered as part of this resource estimate.
Resource classification was based on geological confidence and a spatial review of estimation result parameters which reflected the quality of the estimate for each block. At the Tabakarole deposit, areas that had high confidence estimate values, had sufficient drilling density (≤50m section spaced drilling) or were proximal to 50m spaced drill lines were classified as Indicated Resources. The remainder was classified as Inferred.