Highlights
- Existing JORC 2012 Mineral Resource Estimate of 12.8 Mt at 0.38% copper, 0.14 g/t gold, 2.2 g/t silver & 120 ppm molybdenum
- Yeoval Project (EL8538) covers ~290 km², with over 60 historic copper-gold mine workings along 20 km strike length
- Recent assessment of data highlights additional drilling required at Yeoval and Cyclops prospects
- Typical porphyry Cu-Au style mineralisation at Yeoval with disseminated and vein-hosted chalcopyrite, molybdenite and bornite
- Cyclops Prospect hosts significant copper-gold porphyry potential
- During 2022, Godolphin advanced a two-hole 900m diamond-drill program, which targeted areas north and south of the current Inferred MRE to test for extensions to copper-gold mineralisation. The first hole was drilled at Cyclops prospect, approximately two kilometres north of the Yeoval MRE. The second hole was drilled 350m south of the Yeoval MRE. Assay results confirmed that the drill program intersected multiple zones of highgrade copper mineralisation with coincident gold, silver and molybdenum. Mineralisation remains open along strike, plus up and down dip.
- During the December 2022 quarter, historical drillholes from the Yeoval and Goodrich prospects were relogged to inform upcoming exploration initiatives; both contained copper sulphide mineralisation and porphyry style alteration in unsampled drill core. This work set the platform for exploration programmes across target areas of Cyclops Prospect, Yeoval East Prospect, Goodrich Prospect, and more recently Vaughans Ridge Prospect identified during December 2023 quarter.
- Surface sample results reported during March 2024 quarter include:
- A reconnaissance field trip to a new prospect at Dilga Creek returned excellent copper and gold assays from surface grab samples: up to 1.74% Copper from historic workings in granodiorite
- Mapping and assays from surface rock chip samples taken from Vaughans Ridge support an emerging Iron-Copper Skarn style target
- High resolution ground magnetic surveys have been completed across the Cyclops, Yeoval East and Goodrich Prospects, assisting with the definition of drill targets.
- See Yeoval Resource Update, reported by Ardea in ASX announcement 15 August 2019, utilising a 0.2% Cu cut off; ASX 19 October 2022 Announcement September 2022 Quarterly Report; ASX 19 December 2023 Announcement Yeoval Cu-Au Projects RC drilling completed and new targets identified at Vaughans Ridge; ASX 22 March 2023 Announcement Exploration Update: Strong Copper-Gold Assay Results in Rock Chip Samples from Yeoval and Copper Hill East Projects.
Cyclops Prospect Highlights
- Cyclops Prospect at Yeoval hosts significant copper potential as identified in drillhole GYDD0014:
- 18m @ 0.52% Cu from 118m, including:
8m @ 1.01% Cu from 118m
- 18m @ 0.52% Cu from 118m, including:
- Cyclops copper mineralisation occurs as chalcopyrite ± bornite within chlorite-magnetite-epidote-quartz altered lodes associated with northwest striking shear zones
- RC drilling during December 2023 quarter at Cyclops included intersections of over 1% copper such as:
- GYVRC005 18m@ 0.41% Cu from 32m including:
6m @ 1.21% Cu from 32m
- GYVRC005 18m@ 0.41% Cu from 32m including:
- Mapping initiatives at the Vaughans Ridge Prospect identified highly prospective geology and a vast area of typical skarn style alteration, with gossanous silica, iron oxide and pyrite
Goodrich Prospect Highlights
- Rock chip assays from historic workings at the Goodrich Prospect returned high grade copper and molybdenum with elevated gold, silver, lead and zinc and indicate the nature and tenor of the mineralisation style
- Goodrich prospect rock chips include:
- GRR0366 – 1.54% Cu, 0.15g/t Au, 7.67g/t Ag
- GRR0368 – 0.15% Cu, 3,320ppm Mo, 0.23% Pb
- A two-hole diamond drill program at the prospective Goodrich Prospect, confirmed near surface, high-grade copper mineralisation
- Two styles of mineralisation were intersected, including broad zones of disseminated Cu-Au mineralisation and narrow high-grade vein-hosted Cu +/- Au-Ag-Mo were intersected
- GGDD001 extended the known vertical extent of Cu mineralisation by approximately 30m, as well as the strike length of the mineralisation by approximately 60m to the south-east of the historic Goodrich mine
- GGDD002a identified a new, broader zone of shallower disseminated sulphide mineralisation further to the southeast of the historic Goodrich Mine
- At Goodrich:
- Sulphide mineralisation is generally of the disseminated style, again within grey, variably altered porphyritic granodiorite rock
- High-grade molybdenum (Mo) mineralisation is associated with an interpreted fault breccia with chloritic/epidote alteration
Overview
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 the project. These trend in a north-easterly direction along a 20 km strike length. The project also includes the recently granted neighbouring tenements EL8964 and EL8990.
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.
A Mineral Resource Estimate was disclosed in the Godolphin Prospectus, 29 October 2019.
Resources
Previous owner Ardea Resources completed a Mineral Resource Estimate update in August 2019.
| Category | Tonnes (Mt) | Cu (%) | Au (g/t) | Ag (g/t) | Mo (g/t) |
|---|---|---|---|---|---|
| Inferred | 12.8 | 0.38 | 0.14 | 2.20 | 120 |
| Total | 12.8 | 0.38 | 0.14 | 2.20 | 120 |
|
Based on a 0.2% Cu cut-off Refer to Godolphin Prospectus, 29 October 2019, for JORC statement |
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Background
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, 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).
Geology
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.
The mineralisation style is considered to be a porphyry gold-copper style and consists of chalcopyrite, bornite and molybdenite veins.