Lake Mackay JV




To align with IGO’s strategic focus on clean energy metals IGO prioritises the exploration of terranes prospective for magmatic nickel sulphide and sediment hosted copper deposits.

The Company has acquired exploration access to extensive belt-scale land positions across Australia and in Greenland, and all are highly prospective for multiple Tier-1 base and precious metals discoveries (Figure 1).

Figure 1 - Location Map of IGO's Belt-Scale Exploration Projects and Operations

Lake Mackay is a joint venture between IGO, Prodigy Gold NL and Castile Resources Pty Ltd (in parts), with IGO having earned up to a 70% interest over a holding of 15,630km2of tenements that straddle the state border between Northern Territory and Western Australia.


The Lake Mackay Project tenure is primarily in the Northern Territory, north and northeast of the community of Kintore (Figure 2). The project has the potential to deliver a wide range of mineralisation styles. This potential is demonstrated by the discovery of multiple mineralisation styles by IGO and Prodigy Gold, including:

  • The Grapple and Phreaker (copper-gold-silver ± cobalt) prospects
  • The Grimlock and Swoop (nickel-cobalt-manganese) prospects
  • The Arcee gold prospect.

Significant previously ASX reported drill intersections from the Lake Mackay discoveries include:

  • 7m grading 3.2% Cu, 3.3g/t Au, 37.7g/t Ag, 0.9% Pb, 1.3% Zn and 0.08% Co (Bumblebee)[1]
  • 4m grading 0.8% Cu, 7.9g/t Au, 20.7g/t Ag, 1.1% Zn, 0.5% Pb and 0.1% Co (Grapple)[2]
  • 14m grading 0.84% Cu, 0.14 g/t Au and 4.1 g/t Ag (Phreaker)[3]
  • 8m grading 4.9 g/t Au (Arcee)[4]; and
  • 4m grading 0.6% Co and 0.49% Ni (Grimlock)[5]


Figure 2 - Lake Mackay Project with active prospects (including active drill targets)


The Lake Mackay Project is an IGO first-mover opportunity, in an underexplored belt-scale region considered to be prospective for copper and gold. The project had not had any systematic geochemical exploration prior to IGO’s involvement, and no modern airborne EM completed until IGO’s 2018 survey. The regional ultra-low detection fine-fraction soil sampling programs completed by IGO, combined with ground moving loop EM surveys, has defined the targets that have led to most of the known base and precious metal prospects in the region.

Grimlock is IGO’s most advanced prospect at Lake Mackay. This laterite nickel-cobalt-manganese prospect has been drilled with ten wide-spaced, shallow RC drill holes and each hole has intersected >0.1% Co and >0.1% Ni (Figure 3) [6]. Bench-scale atmospheric leach extraction test work indicated that metallurgical recoveries from high grade cobalt-nickel-manganese duricrust (1.94% Co, 0.47% Ni and 51.9% Mn) are very high with recoveries of >97% of contained cobalt, >99% of the manganese and >85% of contained nickel[7].


Figure 3 - Grimlock Prospect showing drill results <0.1% Co[8], surface extent of prospective lateritic units and TMI1VDRTP image showing the location of the mineralisation along the rim of a heart shaped intrusion


Access to Lake Mackay was restricted through most of 2020 due to the COVID-19 pandemic, but aircore/slimline RC drilling was recently completed at the Grimlock and Swoop nickel-cobalt-manganese laterite prospects, and the Grapple and Goldbug prospects.  All drilling results are pending.

Diamond drilling will be completed at the Phreaker (Figure 4), Raw and Customisable prospects (Figure 2) in CY2021.

An infill soil sampling program was also recently completed across the Western Australian tenement, with assay results still pending. The CY2021 drilling program may also test the extension of the Arcee Gold Prospect and any new soil anomalies that are generated from the recent soil sampling.


Figure 4 - Long Section of the Phreaker Prospect showing RC drill results[9] & planned diamond drill targets


  IGO Lake Mackay Project

ASX Announcement, 6 October 2015, ABM Resources – Announcing the Bumblebee Gold-Copper-Silver-Lead-Zinc-Cobalt Discovery

ASX Announcement, 18 September 2017, Prodigy Gold – Lake Mackay JV – Grapple Prospect Drilling Update

ASX Announcement, 17 July 2019, Prodigy Gold – More Copper and cobalt intersected at Lake Mackay and promising new prospect identified

ASX Announcement, 16 October 2019, Prodigy Gold – Lake Mackay JV Update: New Gold Prospect Identified

ASX Announcement, 30 May 2019, Prodigy Gold – Lake Mackay JV Update: High Grade Cobalt intersected at Grimlock 

ASX Announcement, 30th May 2019, Prodigy Gold NL –, “Lake Mackay JV Update: High grade Cobalt intersected at Grimlock”

7 ASX announcement 12th December 2019, Prodigy Gold NL – “Lake Mackay JV Update: Grimlock Returns +97% Co and Mn Extractions in Leach Testwork”

ASX Announcement, 30th May 2019, Prodigy Gold NL –, “Lake Mackay JV Update: High grade Cobalt intersected at Grimlock”

ASX announcement 17th July 2019, Prodigy Gold NL – “More Copper and Cobalt intersected at Lake Mackay and promising new prospect identified”



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