Mandilla Gold Project
Anglo Australian – 100%
The Mandilla Gold Project is situated in the northern Widgiemooltha greenstone belt in the western part of the Kalgoorlie geological domain, some 70 kilometres south of Kalgoorlie. The location of the project in relation to Kalgoorlie and other nearby gold projects is set out in Figure 1.
The Project lies on the western margin of a porphyritic granitic intrusion, the Mandilla Syenite. The granite intrudes volcanoclastic sedimentary rocks in the project area which form part of the Spargoville Group.
Significant NW to WNW-trending structures along the western flank of the project are interpreted from aeromagnetic data to cut through the Mandilla Syenite and may be important in localising mineralisation at Mandilla East. A second sub-parallel structure appears to host Mandilla South. Both prospects are covered by existing Mining Leases.
The Mandilla Gold Project is covered by existing Mining Leases.
A map of the Mandilla Gold Project, illustrating key locations and geological features, is shown in Figure 2.
On 27 May 2021, AAR announced a maiden Mineral Resource Estimate (MRE) for the Mandilla Gold Project (MGP).
The MRE, which was prepared by independent consultants Cube Consulting in accordance with the JORC Code (2012 Edition), covers the Mandilla East and Mandilla South deposits and totals 15.6Mt at 1.0 g/t Au for 500.4koz of contained gold (see Tables 1 and 2 below).
The completion of a substantial maiden MRE represents a significant milestone for AAR, providing a strong foundation for its plan to develop a long-term gold business in the Kalgoorlie region based on its Mandilla and Feysville Projects (see Figure 1).
The MRE was estimated using a 0.39 g/t Au cut-off and is constrained within pit shells using a gold price of AUD$2,500 per ounce.
The MRE is summarised in Table 1 below, with a more detailed breakdown provided in Table 2.
The locations of the optimised pit shells at AUD$2,500 per ounce gold price are set out in plan view in Figure 3 below, along with the drill collar locations defined by reported gram x metre intervals.
Section 1, as illustrated in Figure 4 below, shows the Mineral Resource within the optimised pit shell at the Mandilla East Main Zone. The overall strip ratio for the pit optimisation is less than 7:1. The outcome of the optimisation also demonstrated a robust pit shell that was relatively insensitive to a reducing gold price.
The gold mineralisation at the MGP appears as a series of narrow, high-grade quartz veins with observable visible gold, with gold grades within these veins of up to several hundred grams per tonne, surrounded by lower grade alteration haloes. Structural logging from diamond core drill holes shows that the majority of the quartz veins are dipping gently (20° to 30°) to the south/south-southeast.
Of note in Figure 4 is a zone of unclassified mineralisation (shown as transparent) at depth, which includes 5m @ 4.23 g/t Au from 264.7m in MDRCD232.
Section 2 as illustrated in Figure 5 below also shows the Mineral Resource within the optimised pit shell at the Mandilla East main zone. This section is 80m south of Section 1 above.
The high-grade zones of mineralisation (coloured purple) coincide with more intense quartz veining.
Top-cutting (grade capping) was applied to restrict the influence of these higher grades during estimation, with a top-cut of 21g/t used within the fresh rock and 12g/t used within the transitional zone. A distance limited threshold was also applied so that the uncapped grades were used for blocks within 10m of the grades above the cap and capped grades used beyond this distance. Cube Consulting considers this an appropriate method to satisfactorily represent the informing data.
Section 2 also demonstrates significant unclassified mineralisation (transparent) beneath the optimised pit shell.
Section 3, as illustrated in Figure 6 below, is located a further 120m south of Section 2 above. MDRCD191 appears on this section and it is the deepest hole drilled to date at the MGP. An interval previously reported as 76.5m at 1.21g/t Au from 296m also included 1m at 42.09g/t Au from 321.1m. MDRCD191 was still in mineralisation towards the bottom of hole, reporting 0.4m at 13.42g/t Au from 410.9m.
The unclassified mineralisation (transparent) is the modelled mineralisation that falls outside the AUD$2,500oz optimised pit shell. Whilst only limited deep drilling has been completed at the MGP to date, , alteration, quartz veining and gold mineralisation has continued to be observed at depth.
Across the 3 sections presented (including Sections 1 and 2 as discussed above) a continuous zone of mineralisation has been modelled at depth which currently sits outside the pit optimisation and hence is unclassified and not reported within the MRE. Mineralisation at depth may be exploitable by way of underground mining, though the economic viability is yet to be evaluated.
Mandilla Gold Project Summary
Mandilla remains the primary focus of AAR, the extensive drilling effort which has included 638 reverse circulation (RC), 10 reverse circulation with a diamond core tail and 36 diamond drill-holes have all been included in the maiden Mineral Resource Estimation.
There are an additional 69 RC and 15 diamond drill-holes that have been drilled and not included in the MRE.
Additional exploration at the MGP is planned for the remainder of calendar year, 2021, this is to include an independent geological appraisal to better understand the controls affecting gold mineralisation, rotary air blast (RAB), RC and diamond drilling.
AAR intends to continue to grow its flagship Mandilla Gold Project to generate the necessary critical mass of inventory to support a central processing hub at Mandilla with satellite ore transported from Feysville.