Wilcherry Project, South Australia (Alliance 100%)
The Wilcherry Project is located within the Gawler Craton, northern Eyre Peninsula, 120 km to the NNW of Whyalla and 40 km north of the township of Kimba, South Australia.
Weednanna Gold Deposit
- Weednanna is a high grade shallow gold system with outstanding economic potential
- 181,000 oz gold resources @ 5.1 g/t gold
- Scoping Study positive and supports a new 250,000 tpa gold plant on site
- Significant exploration upside exists to increase the size of the Mineral Resource and there also exists near-regional potential for new gold discoveries (Wilcherry Gold Camp)
Weednanna is the most advanced gold prospect at the Wilcherry Project. High grade gold is associated with sulphide replacement of magnetite along a granite and calc-silicate contact (gold skarn).
The Mineral Resource Estimate at Weednanna is 1.097 Mt @ 5.1 g/t gold for 181,000 oz gold (refer Alliance’s ASX announcement dated 6 September 2018).
The dimensions of the Mineral Resource area are 1,100 m (north-south), 500 m (east-west) and from surface to a maximum depth of 200 m. The bulk (83%) of the Mineral Resource occurs within 120 m of surface, where there is a higher drilling density, representing a gold endowment of 1,253 ounces per vertical metre.
Significant potential exists to increase the size of the Mineral Resource as the majority of the gold shoots are open at in at least one direction.
There is also potential for the discovery of new gold shoots outside of the Mineral Resource.
The results the Scoping Study for Weednanna confirm a positive and robust gold project, including the construction of a new 250,000 tpa gold processing plant and tailings storage facility for a total capital cost of approximately $44 million, including $8 million open pit pre-strip (refer Alliance's ASX announcement dated 18 April 2019).
Preliminary metallurgical testwork from Shoots 1, 2, 3 and 4 indicates the gold mineralisation is amenable to conventional grinding and cyanide recovery techniques with gold recovery >92%.
Alliance also owns an 80 person accommodation village on leasehold land located in the township of Kimba, which will house the plant construction workforce at the appropriate time.
Mineral Resource Blocks (gold) below optimised Pit Shells, looking west
Regional Gold Potential – Wilcherry Gold Camp
Within a 10 km radius of Weednanna there is >25 km strike length of magnetic iron formations that are known to host gold, highlighting the potential of the district for further discoveries of gold.
Refer Alliance’s ASX announcements dated 7 May 2018, 30 July 2018 and 13 August 2018.
Background and Previous Exploration
The Project area is predominantly overlain by a shallow veneer of transported cover that has prevented exploration by early prospectors. Drilling by modern explorers has identified significant mineralised systems hosted within Palaeoproterozoic calcareous and iron-rich metasediments which are intruded by Hiltaba Suite Granites that are responsible for widespread gold, uranium and base metal mineralisation in the Gawler Craton. The recent discovery of high grade tin, which had previously not been recognised in the district, suggests a more complex mineralised history than previously thought.
The Project area has been explored since the 1970’s by companies including Pan Continental Mining, Asarco and Marumba Minerals for uranium and Broken Hill Type base metals associated with the Paleoproterozoic Hutchison Group metasediments. This resulted in the discovery of the Menninnie Dam lead-zinc-silver deposit (not part of the Project) and the Telephone Dam lead-zinc-silver occurrence.
During the 1980’s The Shell Company of Australia and WMC continued to explore the area for lead and zinc. Shell (later Acacia) in joint venture with Aberfoyle then refocussed exploration onto copper and gold utilising calcrete sampling to identify and prioritise target areas for drill testing.
In 1997 Acacia, identified a strong gold-in-calcrete anomaly at the Weednanna which is coincident with a prominent NNW-trending magnetic anomaly. Successive drilling campaigns identified gold mineralisation associated with skarn alteration and brecciation in the contact aureole of the adjacent granite. Weednanna is now known to be a magnetite breccia in carbonate altered rocks forming a skarn near the contact with a granite intrusion and containing elevated gold, bismuth, tin, uranium, lead and zinc.
In 2002, Aquila Resources acquired the Project tenements to explore for IOCG deposits similar to Olympic Dam. In 2006, Trafford Resources Ltd (Trafford) acquired the Project tenements from Aquila.
Trafford and IronClad Mining Limited (IronClad) made a substantial investment on the Project, including but not limited to, defining Direct Shipping Iron Ore (DSO) in magnetite skarns, banded iron formations and near surface iron oxide deposits. Trafford established Mineral Resources totaling 224 Mt @ 28.8% iron in seven mainly hematite deposits, with 2.9 Mt @ 55.5% iron being either DSO or Dry Magnetic Separation product (source: Trafford Annual Report 2014).
In 2012-13, drilling programs by IronClad to test an outcrop of high grade hematite at the Zealous prospect, 13km NE of Wilcherry Hill, intersected high grade tin (cassiterite) hosted by a magnetite skarn which has been weathered to goethite and limonite. The best intercepts from these programs returned 7m @ 3.28 % Sn from 52m in 12ZLRC007 and 5m @ 2.29 % Sn from 128m in 13ZLRC001. The host rocks are Palaeoproterozoic sediments adjacent to a granite footwall.
The discovery of high grade tin in this region potentially represents a new and significant tin province in South Australia.
Refer to Tyranna ASX Announcement dated 2 August 2016 for further details.