|REGION:||Forestania Greenstone Belt, Western Australia|
|OWNERSHIP:||Earl Grey Lithium Project – 50% Kidman Resources Ltd and 50% SQM; Van Uden Project – 80% Kidman Resources Ltd / 20% Tianqi); Western Areas / Kidman/ SQM – Farmin for Lithium Rights – up to 70%|
|PRODUCT:||Gold & Lithium|
|PROJECT STATUS:||Exploration & Development|
- 54% increase in Earl Grey combined Mineral Resource Estimate
- Estimated to contain 189 million tonnes of 1.50% Li2O or 7.03 million tonnes of Lithium
Carbonate Equivalent; 91% of Resource classified as Measured or Indicated
- Confirms Earl Grey as one of the world’s most significant hard rock lithium deposits
- Expected to be at the low end of the global hard rock cost curve
- JV activity progressing rapidly; proposed refinery site to be announced in next quarter
- High level of interest from various parties seeking lithium hydroxide off-take
Lithium Exploration and Resource Update.
In March 2018, Kidman Resources Limited updated a 54% increase in the combined Mineral Resource Estimate (MRE) for the Earl Grey Lithium Deposit (Earl Grey). Following a
comprehensive 12-month Resource Definition and Exploration drill program, Earl Grey is now estimated to contain 189 million tonnes of 1.50% Li2O, or 7.03 million tonnes of Lithium Carbonate Equivalent (LCE). This is a high confidence estimate with 91% of the estimate classified as Measured and Indicated.
Priority lithium targets include:
- Twinings Group
Priority gold drill targets include:
- Blue Vein
- Van Uden Group
Additional gold targets at:
- Gold City
Kidman has identified multiple targets below historical pits, offering potential for growing the resource inventory
The Mt Holland Gold Field covers southern sections of the Archaean Southern Cross – Forrestania Greenstone Belt. The belt extends over 300km and generally strikes NNW (Stallman and Twining, 1997). Regional mapping identified two distinct lithostratigraphic units within the Belt. They are, 1) an ultramafic metavolcanic suite, and 2) a sequence of overlying immature clastic metasediments. These units are regionally folded with a north plunging synform, a steep east and shallow west limbs (East and West ultramafic-mafic domains) with a core of Package One ultramafic-mafic-sedimentary rocks) (Harvey 2001).
The greenstones are predominantly mafic and ultramafic flows generally intercalated with banded iron formations (BIF), cherts, and clastic sediments. Regional metamorphism is recorded at amphibolite grade, with local areas of retrograde chlorite metamorphic facies. The Belt is enclosed by syntectonic granitoids.
The Eastern Domain mafic-ultramafic basal rocks comprise a thick sequence of tholeiitic basalts with minor high-Mg basalts and exhalative sediments. The basal rocks overlie a granitoid basement, and are overlain by the Bounty sequence. The Bounty sequence is approximately 600m thick and consists of komatiitic peridotite flows and basalts which are intercalated with BIFs. This sequence is host to the Bounty Au mine and the Ni mineralisation within the Forrestania Belt. A dolerite sill overlies the Bounty sequence and is the basal unit in of the uppermost ultramafic suite, which also contains tholeiitic basalts and miner exhalative sediment horizons.
The basal rocks of the Western Domain consist of clastic metasediments which lie upon a younger intrusive granitoid (west). Stratigraphically above the basal metasediments are a thick package of (from bottom to top) komatiitic high MgO olivine orthocumulate; then a low MgO pyroxenite with locally developed dolerite-gabbro differentiates and intercalated flow sediments; then finally a unit of high MgO basalts with intercalated flow sediments (Harvey 2001).
The Central Domain consists mainly of pelitic and psammitic schists (+-garnet), thin BIF lenses and bands of graphitic schists. Two major shear zones in the Forrestania Belt separate the three domains. The Mt Holland Shear defines the Central and Eastern Domains. Likewise, the Van Uden Shear separates the Central and Western Domains. Additional shear zones are recorded as parallel and crosscutting stratigraphy dominantly orientated north south; and north north-west to south southeast (Harvey 2001).
Lastly, NNE striking sets of Proterozoic dykes cut the three domains.
Ten historic open pit gold mines (Darjeeling, Jasmine, Earl Grey, Bounty, Bounty North, Bounty East, Bounty South, Bush Pig, Razor Back, and Blue Vein) and one underground gold mine (Bounty) exist within the tenement package. Gold mineralisation at the Twinings, Bushpig, and Razorback deposits is focussed along the Mt Holland shear. Mineralisation at the Bounty package and at Blue Vein occurs within a sub-parallel shear along a BIF which separates two mafic units.
Substantial progress has been made in the exploration of lithium-bearing pegmatites in the Mt Holland Project in WA.
A significant amount of time has been spent reviewing the extensive exploration catalogue for the district, which has not been explored for lithium and other strategic metals since the mid-1980s.
The focus of this historic work was primarily on the mined tantalum-rubellite bearing pegmatite 10km south of the Bounty Mine and pegmatite intersections in drill holes to the north. Spodumene was noted in many of these pegmatites, along with tantalum- and tin-bearing minerals. The geochemistry of these intersections indicated high levels of fractionation and enrichment in strategic metals, comparable to the pegmatites hosting mineralisation at Greenbushes and in the Pilbara fields.
Within the Mt Holland District three basic varieties of pegmatite have been recognised historically. These include;
- Complex zoned pegmatite containing spodumene and albite in addition to coarse perthite and quartz
- Albitic aplite rich in black tourmaline and commonly containing cassiterite;
- Coarse cleavelanditic albite veins with minor apatite and spodumene
These pegmatites appear to be abundant on the eastern margin of the Forrestania Greenstone belt, where several of Kidman’s tenements occur. Amongst these are the known Bounty Li-bearing pegmatites and the voluminous but currently untested Texas pegmatites.
Despite the presence of lithium and other strategic metals in the district, targeted prospect-scale exploration was never undertaken due to a previous lack of demand for these commodities. The discovery of the massive Greenbushes deposit meant the supply of lithium in the 1980s was easily met by this easily accessible and plentiful deposit, and the commercial utilisation of the product was then in its infancy.
With the acquisition of a dataset spanning 40 years of exploration, Kidman Resources has set about consolidating over thirty databases into one consistent and structured dataset that can be interrogated for the purpose of thoroughly testing this highly prospective region of the Forrestania Greenstone Belt.
Issues have arisen in the past with grandfathering of datasets; this has meant valuable information has been collected by multiple exploration companies, most of which have used a different structures and coding systems, and the understanding the value of the ground they are sitting on is lost or not recognised. Kidman Resources has taken considerable time to evaluate this information and the data that has it has uncovered shows the rich potential of the district.
Widespread systematic exploration at the Mt Holland area was first undertaken during the 1960s Poseidon nickel boom. The 1970s saw a drilling programme 4km south of the current Bounty Main open pit which encountered a thin zone of gold mineralisation. Successive drill programmes resulted in the 1985 Bounty gold deposit discovery. Mining commenced at in 1988, with production continuing through until April 2002. By April 2002, Bounty was estimated to have processed a total of 8.8 million tonnes (“Mt”) at an average mill head grade of 5.12 g/t Au to a vertical depth of 1,065 m below surface.
Previous ownership of the Bounty project area is summarised below:
1960s Amax Exploration (Australia) Inc. in joint venture with Amoco Minerals (Australia) Company conducted nickel sulphide exploration throughout the Forrestania Belt; 1980 – 1985 Harmark Pty Ltd (“Harmark”) acquired the Bounty tenements and entered into a joint venture with Minerals Estate Ltd and Aztec Mining Co. Ltd. (“Aztec”) in 1984. Aztec subsequently became manager/operator of the joint venture; 1985 – 1994 exploration drilling by Aztec intersected the Bounty gold deposit, with production commencing in 1988; 1994 – 1996 Posgold Limited (“Posgold”) acquired Aztec’s stake in the Bounty operation; 1996 – 1997 Harmark, who was now operating as Forrestania Gold NL (“Forrestania Gold”), acquired Posgold’s stake to assume 100% ownership of the Bounty project; 1997 – 1999 LionOre International Ltd (“LionOre”) acquired Forrestania Gold; 1999 – 2001 Viceroy Australia Pty Ltd (“Viceroy”) through its subsidiary Bounty (Victoria) Pty Ltd acquired the Bounty project; 2001 – 2004 Viceroy was placed into administration and the mining operation closed. Viceroy had entered into a hedging contract during 1999 as part of its financing requirements.
The subsequent rise in the gold price resulted in a significant loss that was compounded by rising operational costs. Viceroy subsequently placed its Australian subsidiaries into Voluntary Administration on 24 June 2001. The administrators closed the Bounty gold mining operation in February 2002 after they were unable to meet the debtor’s demands. In 2002 a ‘goodbye cut’ was completed in March, processing continued until April 2002; and 2004 – 2007 Montague announced that its tenement applications over the former Bounty mine and surrounding area had been granted. Montague subsequently entered into a MoA with Nickel Australia. 2007 – 2008 On the 31st July 2007, Montague Resources Australia Pty Ltd was put into Administration pursuant to a Default Event under the Loan Agreement (loan contract dated 14 December 2006 made between Troika Capital Pty Ltd ACN 059 728 282 and Montague Resources Australia Pty Ltd). 28 July 2008, Montague enters into a Deed of Company Arrangement Convergent Minerals Limited. 1 August 2008 Convergent Minerals reaches agreement with the Creditor of Montague and proceedings start to remove Montague from administration. 17 November 2008 transaction with Troika Capital Pty Limited renegotiated and completed. November 2008 Convergent Directors appointed to Montague and process commenced to get Montague out of administration.