Overview
Tungsten exploration within an intrusion related mineral system.
The Marks Hill Project is a tungsten exploration project in central New South Wales, approximately 50 kilometres south-east of Cowra.
Exploration Licence EL9724 covers a north-south corridor of historical tungsten occurrences associated with granitoid intrusions of the Wyangala intrusive complex. Mineralisation has been identified at Reids Flat, Marks Hill, Taylors and Dryburgh, where tungsten-bearing quartz veins and greisen alteration occur near granite-sediment contacts and structurally controlled zones.
Project highlights
- 100% held Exploration Licence EL9724
- Prospective for tungsten, with associated tin and copper mineralisation
- Four established prospect areas along an interpreted mineralised corridor
- Historical mining, underground sampling and limited drilling at Marks Hill
- Greisen-hosted tungsten-tin targets at Reids Flat and Taylors
- Known occurrences remain incompletely tested by modern exploration
- No Mineral Resource has been estimated for the Project
Geological setting
Marks Hill is located within the Lachlan Orogen, where Ordovician metasedimentary rocks have been intruded by several phases of the Wyangala intrusive complex.
Mineralisation is interpreted as an intrusion-related tungsten system associated with shallow intrusive margins, granite cupolas, greisen alteration and structurally controlled quartz veins. Wolframite is the principal tungsten mineral reported across the Project, with scheelite and cassiterite occurring locally.
Two related styles of mineralisation have been recognised:
- Greisen-hosted tungsten and tin mineralisation developed within or adjacent to altered granite.
- Structurally controlled quartz vein mineralisation hosted by metasedimentary rocks near intrusive contacts.
Historical exploration indicates that faulting and fracturing have influenced the position and preservation of the mineralised systems.
Principal prospects
Marks Hill
Marks Hill is a historical tungsten-copper mine developed on several steeply dipping quartz veins. Wolframite is the principal tungsten mineral, with scheelite and sulphides including chalcopyrite and pyrite also reported.
Historical records indicate that the principal veins were initially mined for copper near surface and became comparatively copper-poor and more tungsten-bearing at depth. Cassiterite was also identified in the deeper workings. This distribution was interpreted as vertical mineralogical zoning from a shallower copper-iron assemblage to a deeper tungsten-tin assemblage.
Historical underground sampling and drilling returned locally elevated tungsten and copper values within narrow vein structures. Reported results include individual tungsten assays exceeding 11% WO₃ and copper values above 7,000 ppm from selected historical samples. These results are indicative of locally high-grade mineralisation but are not representative of average grade, and continuity between the sampled structures has not been established.
Reids Flat
Reids Flat contains greisen-hosted tungsten-tin mineralisation developed along a shallow granite-metasediment contact.
Historical mapping and surface sampling identified an altered contact zone containing tungsten-bearing greisen and quartz veins.
The geological interpretation suggests that parts of the prospective contact may continue beneath sedimentary cover, but the target has not been effectively tested by drilling.
Reids Flat is considered one of the Project’s priority exploration areas because it provides an opportunity to test a broader greisen system beyond the narrow vein-style mineralisation historically mined elsewhere in the district.
Taylors
Taylors comprises tungsten-tin mineralisation associated with greisenised intrusive rocks and quartz veins near granitoid contacts.
Historical workings and surface sampling identified wolframite-bearing veins, with minor cassiterite also reported. Historical channel and shaft sampling returned variable tungsten values, including locally elevated grades, but mineralisation appears discontinuous and no drilling has been documented at the prospect.
Dryburgh
Dryburgh contains tungsten-bearing quartz veins and greisen alteration within metasedimentary rocks near an interpreted intrusive contact.
Historical explorers considered the geological setting potentially indicative of a concealed granite cupola. Limited drilling returned only weakly anomalous tungsten values and did not establish significant mineralisation. The prospect therefore remains a conceptual target requiring further geological assessment before additional drilling is considered.
Exploration strategy
ABC proposes a staged programme to validate the historical information and systematically test the principal targets within EL9724.
Initial work is expected to include:
- Compilation and verification of historical sampling and drilling information
- Confirmation of historical workings, sample locations and drillhole collars
- Detailed geological and structural mapping
- Targeted multi-element geochemical sampling
- Assessment of shallow granite contacts and interpreted intrusive cupolas
- Trenching and continuous channel sampling where surface mineralisation is confirmed
- Follow-up drilling of priority targets
The initial priorities are expected to include testing the greisen-hosted system at Reids Flat and assessing the continuity of quartz vein-hosted tungsten and associated copper mineralisation beneath and adjacent to the historical Marks Hill workings.
Important information
The exploration results referred to on this page are historical. Documentation of sampling procedures, analytical methods, survey control and quality-assurance practices is incomplete, and the results have not been independently verified through modern exploration programmes.
Historical samples were commonly collected selectively from visibly mineralised veins and workings and should not be regarded as representative of average grade. Vein thickness and continuity are variable, and the extent and potential economic significance of the tungsten, tin and copper mineralisation remain to be established. No Mineral Resource has been estimated for the Marks Hill Project in accordance with the JORC Code 2012.
