Munglinup Project: Graphite-nickel
The Munglinup project is a highly prospective graphite-nickel sulphide tenement position in the Albany-Fraser Range province of Western Australia.
The Munglinup Project consist of seven tenements, E74/517, E74/518, E74/523, E74/531, E74/538, E74/544 and E74/545, covering 579 km2 in the Albany-Fraser Range province of Western Australia. See Figure 1.
The project tenements are located immediately adjacent to the Halbert’s graphite deposit (1.9Mt @ 19.2% total contained graphite), currently being developed by unlisted Gold Terrace Pty Ltd, and include intersections of up to 34.9% total graphitic carbon (TGC) within a target horizon of over 25km. The project is also highly prospective for nickel sulphide, as it is situated in the Lake Johnston ultra mafic greenstone belt within 15km of First QuantumMineral Limited’s (TSX: FM) Ravensthorpe nickel mine and 40km of Poseidon Nickel Limited’s (ASX: POS) Maggie Hays and Emily Ann nickel sulphide deposits.
Graphite prospects
Renascor has identified multiple drill-ready targets for coarse flake, high-grade graphite of the type located within the adjacent Halbert’s deposit. Halbert’s is among Australia’s highest-grade graphite deposits, with a reported JORC-compliant measured and indicated resource of 1.47Mt at a fixed carbon content of 18.2%[1]. Sixty-seven percent (65%) of the recoverable graphite from Halbert’s is reportedly coarse flake (+150 micron), with 33% classified as jumbo flake (+300 micron)[2]. Gold Terrace Pty Ltd, an unlisted company, recently purchased the Halbert’s deposit for approximately $2.5 million cash consideration.
The regional structure that hosts the Halbert’s deposit, the Halbert’s Shear Zone, extends through Renascor’s new project area over approximately 25km strike extent. See Figure 2. Limited previous drilling within this structure, on E74/518 in Munglinup Central (to the immediate south of the Halbert’s graphite deposit) intersected high-grade graphite, including narrow graphite zones containing up to 34.9% TGC[3]. To the immediate north of the Halbert’s deposit, the Halbert’s Shear Zone extends for approximately 20km to the north on newly acquired E74/517 and E74/531. A recently completed electromagnetic (VTEM) survey over this northern extension has identified several prospective conductive targets that Renascor considers high priority targets for Halbert’s-style graphite deposits, including the Shiraz and Pinot graphite prospects.
Shiraz prospect
The Shiraz prospect is defined by an extensive, +2 km-strike conductive zone, which is coincident with the interpreted northern continuation of the regional Halbert’s shear zone. Two parallel confined conductors each of approximately 800 metres strike-length are defined in “late-time” VTEM data for the southern portion of the zone. See Figure 3. Renascor considers the Shiraz prospect to be a high priority target for near surface, large tonnage graphite of the type located at the Halbert’s graphite deposit to the south.
Pinot prospect
The Pinot prospect is located immediately to the northeast of Halbert’s graphite deposit and appears as a large, +1 km-strike late time conductor. Based on interpretation of available aeromagnetic data, Renascor considers that the conductor is situated at the intersection of a prominent northeast trending fault and the offset northward continuation of the controlling Halbert’s regional shear structure. Geological mapping of the Halbert’s project area indicates that the northeast trending fault may have significant control on development of graphite mineralization in the Harris’ and McCarthy zones of the Halbert’s project. See Figure 4.
Nickel prospects
In addition to its graphite potential, Renascor considers the project area to offer similarly high-priority nickel sulphide prospects. The project tenements are situated in an untested area that is considered to be the southern extension of the Lake Johnston Greenstone belt, the structural setting for Poseidon Nickel Limited’s Maggie Hays and Emily Ann nickel sulphide deposits, located approximately 50km to the north of E74/544. See Figure 1. In 2013, Lithex Resources Limited (ASX: LTX) commissioned a review of the project’s nickel sulphide potential by Western Mining Services Pty Ltd. See Lithex Resources ASX release dated 9 September 2013. The Western Mining Services review concluded that, on a regional scale, the Munglinup project tenements host significant strike length of nickel sulphide prospective ultramafic rocks within an underexplored strike extension of the Lake Johnston Greenstone belt, a known nickel sulphide mineralised province. Limited nickel exploration drilling undertaken by Lithex within E74/518 supports the nickel sulphide prospectivity, with four (of four) holes drilled in a reconnaissance, graphite-targeted drill program in 2013 intersecting widespread hydrothermal veining and alteration, with associated low level copper, potassium and lead anomalism. According to Western Mining Services, the anomalous mineralisation from the Lithex drilling is consistent with the distal expression of a nickel sulphide deposit. See Figure 4. Accordingly, Renascor considers that conductive zones within the identified Greenstone belt offer high potential for nickel sulphides, in addition to graphite.
The Western Mining Service review also interpreted the likely continuation of the Halbert’s Shear to the north and south of Halbert’s graphite deposit, and outlined the possibility that this represents the off-set continuation of the Lake Johnston ultra mafics and nickel sulphide belt. From the recently completed EM survey completed over this area, Renascor has identified several conductors that it considers high priority targets for nickel sulphide mineralisation. As part of its upcoming drill program later this year, Renascor expects to include these targets for initial testing. In addition, the wider tenement area, including, in particular E74/538, contains several known occurrences of outcropping ultra mafic rocks and near-surface geochemical anomalies over areas that have not been subject to detailed EM surveys. In particular, E74/538 contains an historical nickel occurrence at Young River (see Figures 1 and 2), with extensive ultramafic outcrops. Renascor considers the coincidence of a major shear zone and ultramafic host sequence as necessary pre-cursor for nickel sulphide prospectivity. As part of its forward work program, Renascor expects to conduct follow-up reconnaissance work, including airborne of ground EM surveys, in order to general additional nickel sulphide targets.
[1] As reported in Geological Survey of Western Australia (GSWA) Mineral Resources Bulletin 26, in 2015, graphite mineralisation in the Main Halbert’s zone has a “resource estimate subsequently upgraded to a JORC compliant measured and indicated resource by Clifford (2009) to 1.47Mt at a fixed carbon content of 18.2% TC (total carbon) over a strike length of 555m to an average depth of 55m. This resource calculation for Halbert’s Main Zone was based on an in situ ore density of 1.91 t/m3 with a fixed carbon cutoff of 5% TC, and a minimum true thickness of 1.0m for tabular graphite bodies.”
[2] Mineralisation Report in Support of Application for Mining Lease for M74/24, October 2009.
[3] GSWA Bulletin 26. See also Lithex Resources Limited ASX release dated 5 July 2013