Yeoval Porphyry gold-copper-molybdenum-rhenium project (100% Godolphin)
The Yeoval Project is located approximately 70 km northwest of Orange in central New South Wales. The tenement EL8538 covers an area of approximately 290 km². The area is underlain by granites, granodiorites and volcanics, and more than 60 historic mine workings occur within EL8538. These trend in a north-easterly direction along a 20 km strike length. The project also includes the recently granted tenement EL8890.
Another tenement, ELA5780, that abuts the southern boundary of EL8538, is currently under application.
The Yeoval Project area is readily accessible via sealed and unsealed roads and is adjacent to the Molong – Dubbo railway infrastructure. The Project area is within easy reach of the Mitchell Highway to the east.
Ardea has carried out limited soil auger and rock chip sampling, and the tenement is considered prospective for a porphyry gold-copper-molybdenum mineral systems.
A Mineral Resource Estimate was disclosed in the Godolphin Prospectus, 29 October 2019.
The Yeoval Project has numerous minor scale copper and gold historical workings, with the most significant workings located in the Yeoval, Cyclops and Goodrich Prospects.
The tenement (EL8538) covers an area of ~290 km², was granted in 2017 to Ardea Exploration Pty Ltd. Godolphin is exploring for a large tonnage porphyry gold-copper system in the Yeoval area.
The Yeoval prospect is a typical porphyry copper system. The many gold-copper showings in the Yeoval district have been explored almost continuously since the 1960s, though mostly at shallow levels only. Previous explorers have included Noranda, BHP\Newcrest and CRAE.
Previous companies have explored a total of 38 prospects to varying degrees, with much of the work centred on the Yeoval and Goodrich prospects. Of these 38 prospects, 14 have been drilled, including 12 with RC drilling and 7 with diamond drilling. A total of 86 RC holes and 35 diamond drill holes have been completed.
Most of this exploration was carried out prior to the Discovery 2000 airborne magnetics and radiometrics becoming available for parts of the Lachlan Fold Belt including the Yeoval district.
Malachite Resources was the only explorer in recent years to hold all tenure over the Yeoval district, and over a five year period, Malachite conducted a comprehensive exploration program at Yeoval, mainly searching for porphyry style gold-copper deposits, but also high-grade gold vein systems (e.g. Thunderbolt).
Yeoval Project is located in the Cowra Zone of the Lachlan Orogen and contains Devonian granite and granodiorites of the Yeoval Batholith. East and north of the intrusive complex are Silurian and Devonian aged sedimentary and volcanic rocks.
A number of strike-extensive north-south trending fault structures have been mapped in the region, primarily in the Ordovician and Silurian lithologies lying to the east of the Yeoval Batholith. The Batholith itself trends northerly, in a general sense controlled by the north-south faulting. Internally, granodiorite, which forms the eastern third of the Batholith, trends north-north-easterly. Numerous north-westerly trending faults transect the Batholith. These structures also occur in the older lithologies in the south of the licence area.
Interpretation of the local geology has been aided by the regional airborne geophysical data, which was commissioned by the NSW Geoscience Mapping Accord and flown in 1991. Numerous northwest fault sets have been defined from mapping and aeromagnetic interpretation. Detailed magnetics flown by a number of companies have enabled enhancement of the geological and structural interpretation of the Yeoval area.
Copper, gold and other base metal mineralisation is widespread in the region and the main mineralisation styles include Porphyry style gold-copper mineralisation associated with Devonian calc-alkaline intrusions e.g. Yeoval, Skarn mineralisation hosted by mafic units in the Cuga Burga Volcanics, low sulphidation epithermal gold mineralisation in Middle Devonian volcanics and structurally controlled quartz-copper ± gold vein mineralisation in Ordovician to Devonian sedimentary rocks and volcanics.
Ardea completed a Mineral Resource Estimate update in August 2019.
|Category||Tonnes (Mt)||Cu (%)||Au (g/t)||Ag (g/t)||Mo (g/t)|
Based on a 0.2% Cu cut-off
The mineralisation style is considered to be a porphyry gold-copper style and consists of chalcopyrite, bornite and molybdenite veins.
The Mineral Resource Estimate was based on 7,319 metres of historical drilling, consisting of eight RC holes (793 m) and 37 diamond holes. Drilling was carried out in two stages between 1972 & 1975.
No metallurgical or geotechnical studies have been completed on Yeoval drill samples, however as this deposit is considered to be similar other central NSW porphyry copper deposits.
Due to the extensive mining history, encouraging drill results and current Resources, Yeoville is considered to have a good potential for further discoveries and\or extensions of known mineralisation.
Ardea completed an approximate 2 km soil auger program in the southwest corner of the tenement area with results showing elevated copper values (200 ppm to >500 ppm) which warrant follow-up.
The next stage of exploration is expected to consist of reviewing historic data to compile conceptual geological models, extend soil sampling to the south of existing Godolphin soil sampling in the Vaughan’s Ridge area, and designing a drill program around the current Yeoval Resource. The initial expenditure commitment is expected to be around A$0.18M to A$0.34M.