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.
The recent focus of exploration activity at the Mandilla Gold Project has been targeting fresh rock within the Emu Rocks Granite (Mandilla Syenite), where a combination of reverse circulation and diamond drilling continues to delineate a large gold system. The Company progressed substantial exploration activity at Mandilla during the financial year.
Several campaigns of drilling were undertaken representing 20,208m of reverse circulation (RC) drilling and 1,042m of diamond drilling. This represents a significant investment in exploration drilling and demonstrates the Company’s belief in the geological potential of the Mandilla Gold Project.
Campaign 1 – Released 31 July 2019
During July 2019, the Company released results of a drilling campaign undertaken with the objective of gaining a better understanding of the geological setting of gold mineralisation at both the Mandilla East and Mandilla South Prospects. The campaign was co-funded through a grant provided by the Department of Mines and Petroleum, Western Australia under its Exploration Incentive Scheme.
Three diamond holes were drilled for a total of 580 with 153 metres of reverse circulation (RC) pre-collars. This targeted the main Mandilla East zone, extensions to the north of Mandilla East and targeted Mandilla South (Figure 2)
Best results at Mandilla East included:
- 2 m @ 3.79 g/t Au from 65.8 m
- 7 m @ 0.71 g/t Au from 183 m
Best results at Mandilla South included:
- 37 m @ 1.05 g/t Au from 69 m
- 4 m @ 0.89 g/t Au from 152 m
- 1 m @ 15.42 g/t Au from 179 m
The result at Mandilla South represented the first bedrock drilling undertaken at this target. This result was important in that demonstrated the potential for continued mineralisation along the western margin of the Emu Rocks Granite and it extended significant gold anomalism in the granitic intrusion a further 1.2 kilometres from the main Mandilla East zone.
Campaign 2 – Released 16 October 2019
During October 2019, the Company completed an RC program for a total of 36 holes for an aggregate 5,964m. A map of Mandilla identifying the location of the drill holes included in this campaign is set out in Figure 3.
The program was designed to increase the mineralisation footprint at Mandilla East on a 40 x 40 metre spacing. Four of the 36 holes were also designed to test for mineralisation at Mandilla South following on from the success of diamond drill-hole MDD005.
Key results from this program included:
- 45 m @ 4.25 g/t Au from 103 m
- 93 m @ 3.11 g/t Au from 49 m
- 94 m @ 1.17 g/t Au from 101 m
- 112 m @ 1.5 g/t Au from 41 m
- 99 m @ 1.47 Au from 36 m
- 163 m @ 1.75 g/t Au from 37 m
The results at Mandilla East demonstrated a broad steep south westerly dipping gold mineralised envelope. The mineralisation extended for over 500m along strike and remains open to the north and south and at depth.
Campaign 3 – Released 12 December 2019
In October 2019, the Company completed a campaign involving the drilling of 55 shallow (“slimline”) reverse circulation (“RC”) holes for 2,235 metres. The programme was designed to penetrate a short distance into fresh rock to test various extensional targets at Mandilla, with the objective to expand the footprint of significant mineralisation. A map of Mandilla identifying the location of the drill holes included in this campaign is set out in Figure 4.
The average depth of these holes was 41m. Assay results from all holes were reported in the ASX release dated 12 December 2019. Best results from the program included:
- 25 m @ 2.2 g/t Au from 24 m
- 4 m @ 2.31 g/t Au from 45 m
- 4 m @ 4.43 g/t Au from 38 m to EOH
The slimline RC program demonstrated the potential for a second zone of mineralisation up to 800 along strike closer to the western margin of the Mandilla Syenite intrusion. Additionally, this program also demonstrated a potential 400m extension of the mineralisation at Mandilla East to the north.
Three RC pre-collars for a 3-hole diamond drill program were also completed and reported as part of this campaign MDRC165 reported an intersection of 37m @ 1.64g/t from 104m.
Campaign 4 – Released 12 February 2020
A 16-hole RC drill campaign for an aggregate 2,750m was commenced in late December and was designed to in-fill the core of the main Mandilla East zone. The RC drilling met with considerable success, further demonstrating the thick high-grade nature of the mineralisation. This campaign was able to extend the main Mandilla East zone to the South. The location of the drill holes are presented on Figure 5 below. Best results included:
- 45m @ 2.33g/t Au from 82m
- 21m @ 4.53g/t Au from 89m
- 42m @ 1.85g/t Au from 45m
- 41m @ 1.36g/t Au from 59m
- 21m @ 2.39g/t Au from 85m
- 15m @ 3.47g/t Au from 54m
- 14m @ 3.18g/t Au from 31m
Campaign 5 – Released 19 June 2020
In June 2020 Anglo Australian released the results from 9,106 m of RC drilling and 445m of diamond tails. This RC and diamond drilling campaign tested the main Mandilla East mineralised zone, tested for extensions to the north and south of Mandilla East and followed up previous bedrock mineralisation drill results at Mandilla South.
This was the most significant single campaign completed to date at the Mandilla Gold Project and it continued to deliver successful results, demonstrating further extensions along strike to the north and south of Mandilla East and also delivered a 500m long bedrock mineralised zone at Mandilla South.
At Mandilla East, diamond drilling demonstrated the extension of mineralisation to a vertical depth of 230m below surface with best intersections including:
- 95m @ 8.31g/t Au from 163.1m plus 24.1m @ 2.11g/t Au from 216.35m
- 6m @ 1.49g/t Au from 182.5m
Extensions along strike to the north and south of Mandilla East were demonstrated with the bedrock mineralisation extending from 500m to over 1,000m of strike. A map of Mandilla identifying the location of the drill holes included in this campaign is set out in Figure 6 below. Best intersections included:
- 26m @ 8.29g/t Au from 76m
- 21m @ 3.7g/t Au from 35m
- 17m @ 3.71g/t Au from 59m
- 9m @ 5.89g/t Au from 76m
- 38m @ 1.34g/t Au from 38m
- 14m @ 2.19g/t Au from 34m
A total of 12 holes were drilled at Mandilla South and represented the most significant bedrock drilling to date at the Mandilla South target. This program successfully delineated a 500m long mineralised footprint and combined with detailed magnetic imagery collected by the Company provides an opportunity for Anglo Australian to delineate a mineralised zone of similar scale to Mandilla East. Best intersections included:
- 27m @ 1.79g/t Au from 168m plus 10m @ 1.76g/t Au from 123m
- 16m @ 1.65g/t Au from 188m plus 31m @ 0.53g/t Au from 131m
A high-resolution drone magnetic survey (DroneMag) was completed in March 2020. Areas of low magnetic susceptibility have been demonstrated previously to closely correspond with reported mineralised intervals, such as at Mandilla East. Accordingly, magnetic low domains in detailed magnetic data appears to outline gold related alteration and assists in both validating current geological interpretations and generating new exploration targets.
Figure 8 below shows the extensional targets to the north and south of Mandilla East. These extensional targets correspond with areas of low magnetic response that are also associated with identified structures. Initial RC drilling confirmed the Mandilla East extensions directly to the north and south. A second zone in the south-east was also located oriented along a NW striking structure. A NNW trending target to the north of Mandilla East is still to be fully tested as previous drilling targeted a zone further west on a north-westerly orientation.
Follow-up drilling is planned to test targets highlighted in the DroneMag (as depicted in Figure 8) and to in-fill the new north and south extensions to further extend the mineralisation at the Mandilla Gold Project. Additionally, the Mandilla South target appears to be of similar scale to that of Mandilla East with only limited RC drilling to date. Follow-up diamond and step-out RC drilling is planned at Mandilla South. This drilling will also investigate the potential for a mineralised corridor between Mandilla East and Mandilla South.
Mandilla Gold Project Summary
Following the most extensive exploration drilling effort ever undertaken at Mandilla during the 2020 financial year, the Company has delineated a potential large bulk scale gold mineralised system. The bedrock mineralisation now represents over 1,000m of strike extent at Mandilla East and remains open along strike in both directions. More recently and post year end, the mineralisation has been defined to over 350m of vertical depth.
At Mandilla South the bedrock mineralisation has been defined to over 500m of strike, Mandilla South remains very lightly drilled and presents a potential scale of mineralisation similar to Mandilla East.