In early 2017 Intermin executed a binding Heads of Agreement to purchase a 100% interest in the Anthill gold project located 54km northwest of Kalgoorlie-Boulder in Western Australia. The project is located on the highly prospective Zuleika Shear and contains a global JORC (2004) Indicated and Inferred Mineral Resource Estimate completed by SRK Consulting in 2011 of 160,700oz.
Mineralisation is open in all directions and to date has been defined extending from surface to ~200m vertical depth. Follow up drilling of very high grade intercepts within the Resource will be prioritised to improve structural interpretation and to assess potential for definition of a larger higher grade Resource. Significant downhole intercepts >5g/t Au from historic RC drilling include:
4m @17.89g/t Au from 89m and 2m @ 24.75g/t Au from 109m (CXRC004)
3m @ 31.25g/t Au from 134m (CXRC006)
1m @ 88.90g/t Au from 76m, 5m @ 19.25g/t Au from 159m and 1m @ 31.10g/t Au from 197m (CXRC007)
1m @ 24.10g/t Au from 237m (CXRC010)
In addition, recent aircore drilling returned significant shallow mineralisation outside the Resource envelope providing immediate new drill targets to be tested in mid-2017.
Preliminary metallurgical testwork conducted in 20112 on oxide, transitional and primary samples indicate favourable total gold recoveries of 93 – 99%. Work is currently underway to verify technical database, upgrade the Resource to JORC (2012) compliance and generate priority Resource extension targets.
The Anthill gold project is located directly within the regionally significant Zuleika Shear zone and is immediately along strike from operating high grade gold camps including Bullant (+1.0Moz), Broads Dam (+4.0Moz), Kundana (+7.0Moz) and Frogs Leg (+1.5Moz) all owned and operated by major gold producers (Figure 1). The project consists of one granted Mining Lease (M16/531) and one Miscellaneous License for haulage (L16/92) covering an area of 700 Ha.
Previous operators of the project include Plutonic Operations Ltd, Homestake Gold of Australia Ltd, Placer Dome Asia Pacific and Metaliko Resources Limited who conducted over 700 RAB, reverse circulation (“RC”) and diamond drill holes within discontinuous exploration programs since 1986.
The deeper parts of the mineralisation zone are only tested by a small number of drill holes and its depth extent remains open. A drilling plan with the current Resource outline location highlighting a north-south and east west section is shown below.
The project is located in part of the Depot Domain of the Kalgoorlie Terrane and there is no outcrop as it is blanketed by sheet wash material. Interpretation of aeromagnetic and drilling data indicate the project area is underlain by metamorphosed sedimentary and felsic volcanic–volcaniclastic rocks including komatiite basalt intruded by felsic, albite-rich, quartz-poor porphyritic rock. There is also an interpreted dolerite intrusion closely related to known mineralisation. Anthill is located on a bifurcation of the important Zulekia Shear where a zone of quartz stockwork hosted gold mineralisation was discovered under a soil anomaly.
Further south the Zuleika Shear is an important structural control on the localisation of several gold deposits including the Blue Funnel and West Black Flag deposits hosted in ultramafic rocks, the Zuleika deposit hosted in altered mafic rocks and closer to the Anthill project area the Hawkins Find and Ant Hill deposits hosted in sulphide bearing porphyry intruded into metamorphosed ultramafic rocks (talc–chlorite–carbonate schist).
As with mineralisation at Anthill, the larger high grade deposits along the Zuleika Shear, are hosted within massive, planar quartz–carbonate veins and within lesser, sheared, bleached, carbonate–chlorite–sericite–pyrite–pyrrhotite altered mafic rock and granodiorite. A zone of strong carbonate alteration has been delineated at Anthill and represents the key mineralisation target for Resource extension.
Significant visible gold has been logged in historic drill holes corresponding to very high grades and a relationship with a quartz-carbonate vein set dipping at 20° to the south is prominent. There are however, more complex mineralisation controls evident, a fact further complicated by the use of multiple drilling grids.
Intermin entered an agreement to purchase a 100% interest in the Anthill gold project from Echo Resources Ltd (ASX: EAR) (“Echo”) in the March Quarter 2017. Key terms of the acquisition include:
- Intermin to pay Echo $300,000 in cash on or before 30 June 2017;
- Intermin to pay Echo a gold production royalty of $5/oz for the first 100,000 ounces mined from the project.