copper/gold project

The Clermont Copper/Gold Project (EPM 17968) is situated around the town of Clermont in central Queensland. The project is prospective for porphyry and stratabound bulk tonnage copper/gold deposits along with mesothermal gold deposits. 

The project area covers numerous prospects including the Rosevale Project and the historic Peak Downs Copper Mine.

The three main targets comprise:

  1. Rosevale Porphyry Corridor, which has potential for porphyry-related copper, gold and molybdenum; 
  2. Structurally controlled gold (vein) mineralisation (western and eastern parts of tenement); and 
  3. VMS-related base metal mineralisation associated with the historic Peak Downs copper mine.

On 5 August 2021, Diatreme announced a farm-out with Metallica Minerals Limited (ASX:MLM) under which Metallica can earn a 25% interest in the project by sole funding exploration expenditure of A$300,000 by 31 December 2021.

Metallica can earn an additional 26% interest by sole funding exploration expenditure of an additional A$700,000 by no later than 12 months after 31 December 2021. After spending this amount, Metallica has the right to sole fund the first A$1 million of joint venture expenditure to earn an additional 24% interest. Should Diatreme and Metallica make the decision to mine, Diatreme will be granted a 1% net smelter royalty.

On 26 October 2021, Metallica requested an extension to the initial expenditure stage, which was agreed by Diatreme and extended to 29 April 2022. 

The key terms of the MOU comprise:

• Metallica to invest a minimum of $300,000 on exploration expenditure no later than 29 April 2022 to earn a 25% interest in the project;
• Should Metallica commit to continue to invest in the project, by investing a further $700,000, Metallica will gain an additional 26% interest;
• Metallica will then have the right to invest a further $1 million in the joint venture to hold a 75% interest;
• The partners will then be entitled to contribute further funding to the project on a pro-rata basis.


On 29 April 2022, Metallica announced it had met the MOU’s expenditure commitments to earn 25% of the project and had made the decision to move to the second stage, increasing its interest to 51% through spending an additional $700,000 on exploration prior to 27 April 2023.

Metallica has drilled two diamond holes at Clermont, RDD019 and RDD020, totalling 1,030.4m. The two holes were drilled to test a possible copper gold exploration target withing the Rosevale Porphyry Corridor.

Porphyry style alteration was intersected in both drill holes, with potassic and phyllic alteration observed in both and with the intensity of alteration increasing with depth. Sulphide mineralisation in the form of iron pyrite, chalcopyrite and molybdenum was also observed in the core removed from both holes.

On 13 July 2022, Metallica reported assay results for the two diamond drill holes. Anomalous copper was recorded in both drill holes, with grades ranging from 5ppm Cu to 1,840ppm Cu in hole RDD019 and 2ppm to 3,460ppm Cu in RDD020. Molybdenum grades ranged from <1ppm Mo to 312 ppm Mo in RDD019 and from <1ppm Mo to 87ppm Mo in RDD020. Gold grades ranged from <0.01 to 0.11 Au in RDD019 and from <0.01 ppm Au to 1.75 g/t Au in RDD020.

The assay data showed a distinct increase in copper mineralisation with hole depth, with the highest copper assays recorded at the base of each hole. The same trend was also evident with silver assays in RDD020. The highest recorded gold assays occurred in the bottom 30m of RDD020, with the highest gold intercept of 2m @ 1.69 g/t Au recorded in hole RDD020 from 475m.

Geochemical modelling, especially of the tin and tungsten assays, indicated that both drill holes possibly intersected the porphyry immediately above or adjacent to the expected location of the more mineralised core.

This work indicated that a potential porphyry target may be located beneath the depth of the current drilling and extending one of the holes to test this was warranted. Hole RDD020 will be extended by an additional 500m to 1,000m to determine if the copper, gold and silver grades continue to increase with depth and if the intensity of the alteration also increases.

On 4 July 2023, Metallica announced assay results for the extension to diamond drill hole RDD020 drilled in April and May 2023. Under the terms of the MOU with Diatreme, on the completion of this drill hole, Metallica has met the expenditure condition to move to a 51% share of the Clermont Project. Further information is available from Metallica’s ASX release dated 4 July 2023.

The Peak Downs Copper Mine was worked between 1863 to 1877, with 17 000 tonnes of copper reported to have been produced from the mining and smelting operations on site. The Peak Downs mine workings lie within the Bathampton Metamorphics and exploited supergene mineralisation from VMS related mineralisation.

Previous gold mining activity in the region included mining of placers in Permian conglomerates and from Tertiary and Cainozoic alluvial deposits. Gold was discovered in gullies to the south of Clermont township in 1861 and by 1862 mining extended from McDonalds Flat in the southeast to Hurley's Lead in the northwest. The main centres of alluvial mining were in the area adjacent to the Clermont township.

Between 1877 and 1901, recorded gold production amounted to 5,458 kg from deep leads and other alluvial sources and only 308 kg from quartz lodes. Production from the Clermont Goldfield during the period 1862 to 1901 is documented as 8 200 kg of gold. Mining activity declined after 1910 and by the 1920s had almost ceased. In 1931 a new lead, discovered at Miclere, sparked a revival of mining, which continued through to the mid 1950s.

During the 1980s and early 1990s small to medium-scale alluvial mining was carried out at McDonalds Flat, Bathampton, and Expedition Creek. Total gold production for the Clermont area to 1993 is estimated to be about 14,000 kg. Three main targets have been identified:

  • Rosevale Project (gold, copper-molybdenum);
  • Mesothermal gold reefs; and
  • Peak Downs copper mine.

exploration overview

The Rosevale Porphyry Corridor (RPC) has the potential to host a large buried porphyry copper - gold - molybdenum mineralised system. This prospect was discovered by Diatreme in 2008 and work has included deep diamond core drilling which has assisted in identifying porphyry related copper/molybdenum and breccia hosted silver/lead/zinc/gold mineralisation.

Exploration over Clermont has resulted in an improved understanding of the geology and mineralisation of the Rosevale Porphyry Corridor. This work has highlighted drill-ready porphyry copper targets. At the Gollan Prospect toward the northern end of the Rosevale Porphyry Corridor, Diatreme has defined from drilling a wide zone of haematite-bearing propylitic alteration of the intrusives, located in a zone of abundant secondary carbonate copper on surface. The geological setting is reminiscent of the high grade Ridgeway deposit at Cadia NSW.

Exploration in 2012 resulted in the discovery of the Savannah Prospect to the southeast of the Rosevale Porphyry Corridor. Mapping and rock chip results from Savannah have return significant results of up to 25ppm gold, 80ppm silver, 1.8% copper, 1.4% lead, and 1.4% zinc over a strike length of 1.4km.

A number of structural trends are known within the tenement area and the Anakie Inlier generally, but the most significant of these are the faults and shear zones that have associated silicification with gold mineralisation. Gold mineralisation in the Clermont area occurs in a number of geological environments. Quartz reefs in the Anakie Metamorphics sequence are known to contain gold mineralisation and deposits of this type accounted for some historical gold production.

Most of the past exploration on the known gold bearing quartz vein systems within the Anakie Metamorphics has shown these to be small. These veins are the likely source of at least some of the alluvial gold deposits in the Clermont area. However the amount of alluvial gold at Clermont is not in accordance with the known gold bearing quartz vein and shear occurrences.

This is the case immediately south of Clermont where there is no significant known source for the amount of gold that was mined from the rich Wild Cat lead and other leads in this area. This suggests that, either there are undiscovered gold bearing quartz veins in this area, or another hard rock source exists for the gold. It is the potential for an alternative hard rock source for the gold found in some of these alluvial deposits near Clermont that has driven gold exploration in the district.

rosevale project

Copper was mined at the Peak Downs Copper Mine following its discovery in 1862 and during the period to 1877, 17,000 tonnes of copper (100,000 tonnes @ 17% copper) is reported to have been produced from the mining and smelting operations on site.

The Peak Downs mine workings are situated 6km south of Clermont. with The copper mineralisation appears to be of a volcanic hosted massive sulphide type with a basic volcanic association that has a supergene cap. Mineralisation principally consists of pyrite and chalcopyrite associated with a narrow banded siliceous iron formation.

A number of historic resource estimates have been estimated for Peak Downs that require further work to be JORC compliant. These estimates indicate Peak Downs contains approximately 30,000 tonnes of copper close to surface that would be capable of being mined and processed by a conventional heap leach solvent extraction - electrowinning (HL SX-EW) mining operation.

Further drilling and bulk sample test work is required for the resource to be JORC compliant and for feasibility studies to be carried out. Copper has been mined historically from many smaller underground mining operations throughout the Clermont tenement and these have been the subjected to numerous exploration programmes to date over the Clermont tenements.

Further exploration is warranted over Clermont particularly over the Rosevale Porphyry Corridor, and Peak Downs for copper, Savannah for gold and base metals and at the Palm Trees Prospect (near the historic McDonalds Flat mines) for gold.

Peak DOwns project