The Thunderbox Operations are centred on the Thunderbox Open Pit and CIL gold treatment plant; located 45km south of the town of Leinster in Western Australia and immediately adjacent to the sealed Goldfields Highway. The Thunderbox processing facility has an annual capacity of 2.5 Mtpa and incorporates a single-stage crusher, a SAG mill and a ball mill as well as conventional CIL leaching and elution circuits.


    Thunderbox mineralisation is hosted in an intermediate intrusive porphyry, in the hangingwall of the Thunderbox Shear Zone. The shear zone is over 200m wide and the mineralisation is predominantly confined to the intrusive porphyry, which is upto 80m in width. The mineralisation is cut and offset by a major fault known as the Gap Fault. This fault is what separates the two key domains, Zone A and Zone C.



    During the third quarter of FY2015 the Saracen Board approved the development of our 100% owned Thunderbox Operations following the completion of the feasibility study. The development of Thunderbox has seen the Company achieve its medium term vision of becoming a mid-tier gold producer with gold production doubling to approximately 300,000 ounces per annum by FY2017. Pre-strip mining of Thunderbox pit commenced in July 2015.


    • Completion of the feasibility study for the Thunderbox Operations - Stage 1;

    • Feasibility study showed robust project economics for Stage 1 over an initial 4.5 year mine life;

    • Board approval for the development of Stage 1, a large open pit on the Thunderbox deposit delivering 597,000 ounces with all in sustaining costs of A$1,032/oz;

    • Gold Hedging program of 140,000 ounces at an average price of A$1,520/oz entered into with Macquarie Bank Limited (MBL) to underpin the initial capital investment;

    • Project capital requirements of A$65 million is fully funded from existing cash reserves and free cashflow generation from our  Carosue Dam Operations;

    • Project loan facility of A$33 million with MBL available as a standby;

    • Project development to commenced in August 2015 with prestrip mining in Zone “A”;

    • Mill production commenced in January 2016 following a plant refurbishment period of 4 months;

    • Project statutory approvals complete with full permitting acquired in 2015;

    • Key personnel in place comprising much of the same team who successfully completed the Carosue Dam refurbishment and resumption of mining in 2009;

    • Commencement of mining coincided with the completion of the Whirling Dervish open pit, allowing a seamless integration between operations;

    • Various opportunities to extend the Project life beyond Stage 1, including a bulk underground mine at Thunderbox and satellite open pit opportunities.


    Managing Director, Raleigh Finlayson, said:

    “The development approval for the Thunderbox Operations is a significant milestone for the Company that will see Saracen produce gold from multiple operations for the first time in our history. More importantly, this will realise our vision of joining the likes of Northern Star, Regis, OceanaGold and Evolution as mid-tier gold producers, with production in excess of 300,000 ounces per annum following the commencement of Thunderbox production in FY2017.