High-grade copper and rare earth elements (100% TAR)

The Mt Craig Copper Project (MCCP) spans more than 850km2 covering 40km of prospective strike centered around a major structure – the Worrumba Anticline. High-grade copper and ionic adsorption clay (IAC) style rare earth elements (REE’s) were discovered at the MCCP during 2021 drilling. During 2022 Taruga completed a 2,156m Rotary Air Blast (RAB) drilling program (59 holes) at Morgans Creek, testing for strike extensions of clay hosted REEs discovered in 2021 reconnaissance drilling.


  • Exceptional clay-hosted REE grades of up to 9,082ppm (0.91%) TREO1 with multiple holes mineralised from surface and to end of hole (EOH)
  • New assays extend mineralised strike by 300%, from 1.4km to 4.3km (open)
  • Very high basket average of 34% MREO (Nd + Pr + Dy + Tb), which is significantly higher than the peer average of 25% MREO, with high levels of Dysprosium and Terbium 
  • High-grade sediment hosted copper discovered by Taruga at Wyacca in 2021 RC-drilling, including 11m @ 1.5% Cu from 85m (WCRC021), 7m @ 1.8% Cu from 85m (WCRC017) and 5m @ 2.4% Cu from 17m (WCRC006)
  • High value magnetic rare earth elements (Nd + Pr + Dy + Tb) discovered by Taruga at Morgan’s Creek in 2022 drilling, including:
  • 43m @ 1,687ppm TREO from surface to EOH (40% MREO) from MCRB044 (Hydrothermal Hill) including:
    • 5m @ 3,343ppm (0.33%) TREO from 12m, with 1m @ 9,082ppm (0.91%) TREO from 13m (44% MREO)
    • 14m @ 2,979ppm (0.30%) TREO from 29m to EOH, with 2m @ 7,052ppm (0.71%) TREO from 29m (42% MREO)
  •  40m @ 1,582ppm TREO from surface to EOH (41% MREO) from MCRB045 (Hydrothermal Hill) including:
    • 17m @ 2,636 (0.26%) TREO from 11m, including 
    • 5m @ 4,930ppm (0.49%) TREO from 19m with 1m @ 6,234ppm (0.62%) TREO from 21m
  • REE testwork and indicates an ionic adsorption clay (IAC) style with a high concentration of readily soluble REE’s. In the weathered zone, average recoveries of:
    • total rare earth element oxide (TREO2) has increased from 68% TREO to 72% TREO
    • high-value magnetic rare earth element oxides (MREO3: Nd + Pr + Dy + Tb) has increased from 70% MREO to 75% MREO
    • heavy rare earth element oxide (HREO) has increased from 53% HREO to 62% HREO
  • Average recoveries in the clay zone remain unchanged at 85% TREO and 93% MREO
  • Fresh rock REE recoveries have also increased, and indicate a high REE solubility of 47% of the TREO and 50% of the MREO in the fresh rock zone 
  • Copper and REE Mineralisation centred around a major structure, the Worrumba Anticline, which strikes for over 40km and remains largely untested
  • Significant historical drilling results at Birthday Ridge including 23.4m @ 0.61% Cu from 3.4m 

Project overview

The Mt Craig Copper Project (MCCP) is prospective for a range of mineralisation styles, including polymetallic skarn, sediment-hosted copper and REE’s. Prospective Mineralisation Styles at MCCP:

  • Central African Copperbelt style sediment hosted Cu
  • Magnesian Skarn (Cu-Co-PGE)
  • Ionic Adsorption Clay (IAC) style REE’s
  • MVT style Cu-Pb-Zn
  • Kipushi style (Cu-Zn-Pb-Ag-Au)

The MCCP is situated within the Adelaide Fold Belt (AFB), and lies at the intersection of the G2 and G8 structural corridors (lineaments). The G2 and G8 lineaments mapped by O’Driscoll led to the discovery of Olympic Dam, and reflect the deep lithospheric structure of Australia, hosting the majority of South Australia’s major base metal deposits. 

The AFB has hosted over 800 historical copper mines or workings, and multiple polymetallic mines since the 1840’s. Copper-gold associations are common within the AFB, with many of the old copper mining ventures not recognising the presence of gold and other metals such as REE’s which were not assayed for. Modern exploration has continued to uncover significant large-scale, polymetallic, base and precious metal potential around historical mining regions within the AFB, which have undergone limited exploration and development since initial mining ceased in the late 1800’s.


Wyacca is host to approximately 15 locally significant historical artisanal mines operated in the 1800’s, where high-grade oxide ore was extracted from the outcropping gossans within the Tindelpina Shale Member (TSM). Limited exploration drilling completed by various companies between the 1960’s and 2012 returned low-grade sniffs of copper mineralisation, and it was assumed that the IP and EM responses were due to the pyritic shales of the Tapley Hill Formation.

However, high-grade sediment hosted copper was discovered by Taruga in 2021 (Figures 3 & 4) at Worrumba 19 and Powder Hill prospects. Structurally controlled high grade copper mineralisation which has a gravity and magnetic high signature will be the target of future drilling at Wyacca.

Morgan’s Creek

Morgan’s Creek (Morgan’s) sits at the southern end of the MCCP, approximately 34km south of Wyacca. A large diapiric breccia outcrops at Morgan’s and contains large dolerite and gabbro intrusions which have produced a large skarn alteration system. Morgan’s Creek geology includes large exposures of highly reactive trap rocks such as the Skillogalee Dolomite and the Yednalue Quartzite, which are known to host significant copper mineralisation in the region, including the Burra Monster Mine (Cu). There are several historical artisanal mines at Morgan’s which initially drew attention to the area, along with the favourable geology and structural setting.

Taruga drilling in 2021 intercepted low grade sediment-hosted copper mineralisation at Morgan’s Bore prospect, with 23m @ 0.2% Cu from 20m including 8m @ 0.4% Cu, along with low grade copper sulphide mineralisation in a skarn alteration system at Hydrothermal Hill which included 20m @ 0.23% Cu from 158m.

Further drilling intercepted significant high value magnetic rare earth elements, despite these not being targeted. Drill results included 27m @ 1050ppm total rare earth element oxides (TREO) from 21m, including 10m @ 1996ppm TREO, 6m @ 1,210ppm TREO from 9m, and 3m @1,715ppm TREO from 39m. Metallurgical testwork indicated an ionic adsorption clay style of mineralisation with a very high concentration of readily soluble rare earth elements, which supports a simple and low-cost metallurgical flowsheet critical to the economics of REE deposits. Indicative recoveries included average recovery of 85% of the TREO and 93% of the magnetic rare earth elements (MREO).

Further exploration drilling targeting both the copper and the REE mineralisation at Morgan’s is planned for July 2022, along with further REE metallurgical test work.

Birthday Ridge 

Historical data review and compilation revealed high-grade historical trenching results from surface exposures at Birthday Ridge:

  • 0.3m at 12% Cu (Birthday Ridge) 
  • 1.2m at 3.8% Cu (Birthday Ridge) 
  • 1.6m at 3.7% Cu (Birthday Ridge) 
  • 3.7m at 2.4% Cu including 1.2m at 5.8% Cu (Birthday Ridge) 
  • 1.6m at 2.3% Cu (Birthday Ridge) 
  • 1.5m at 4.8% Cu (Napoleon)
  • 1.5m at 3% Cu including 0.6m at 6.4% Cu (Napoleon) 
  • 1.8m at 1.9% Cu (Napoleon)

7.9m at 1.7% Cu including 4.3m at 2.5% Cu and 0.6m at 5.1% Cu (Napoleon) 

Historical drilling at Birthday Ridge discovered significant shallow sediment-hosted copper mineralisation over 2km of open strike (Figure 6), which has not been followed up by modern exploration.   Most holes either started in or ended in mineralisation, and it is believed that only the leached-zone has been tested thus far. Historical drilling results at Birthday Ridge included:

  • 23m @ 0.6% Cu from 3m (GLC 45)
  • 8m 0.8% Cu from 3m to EOH (GLC 47)
  • 21m @ 0.3% Cu from 3m to EOH (GCL 53)
  • 44m @ 0.2% Cu from surface (GCL 15B)

Napoleon (Cu – Ag – Zn)

The Napoleon Prospect is defined by a NW trending, 3km x 1km copper in stream sediment anomaly of >50ppm Cu which lies perpendicular and coincides with the Worrumba Anticline at its south-eastern margin as shown in Figure 7. The prospect has had limited drilling (7 drill holes in total). The Napoleon geochemical anomaly is associated with a strong magnetic anomaly along the Worrumba anticlinal axis in the SE and a coincident gravity and magnetic anomaly in the NW as shown in Figure 10 which is covered by a stream sediment anomaly of >50ppm Cu. At least 12 small scale copper workings have been recorded historical ally within the prospect area with limited drilling only being carried out around these workings.

Trenching carried out historically by Gold Copper Exploration Pty Ltd reported best results of 1.5m at 3% Cu including 0.6m at 6.4% Cu, 7.9m at 1.7% Cu including 4.3m at 2.5% Cu and 0.6m at 5.1% Cu and 1.5m at 4.8% Cu confirming significant copper mineralisation at surface.

Drilling reported best intersections of 27.5m at 0.2% Cu from 3.3m in GLC 58 and 13.3m at 0.2% Cu from 16.3m in GLC 59 although the drilling did not target either of the stream sediment or geophysical anomalies which remain untested. The true potential of Napoleon will only be realised from detailed exploration and drilling.

  • 1.5m at 4.8% Cu 
  • 1.5m at 3% Cu including 0.6m at 6.4% Cu 
  • 1.8m at 1.9% Cu 
  • 7.9m at 1.7% Cu including 4.3m at 2.5% Cu and 0.6m at 5.1% Cu 

Hawk Prospect (Au – Cu)

A significant gold in soil anomaly covering 1000m x 500m (Figure 11) with anomalous gold and copper drill results shown in section in Figure 12 was identified from soil sampling and shallow drilling at the Hawk Prospect in the NE of MCCP as shown in Figure 2. Hawk Prospect is associated with a high-intensity magnetic anomaly which is yet to be explained. Two vertical holes and one angled hole were drilled which were most likely drilled at convenient locations and reported best intercepts of 10m at 0.2g/t Au including 4m at 0.3g/t Au from 52m and 20m at 245ppm Cu from 64m in hole HKRC01 and 46m at 270ppm Cu from 2m in HKRC03.

The Company considers the drilling to be inadequate in testing the true gold potential of the source of the gold in soil anomaly and will follow up with mapping and sampling to better understand the mineralised potential of the anomaly and historical hole positioning.

Iron King (Cu-Fe-Au)

Iron King sits at the flexure point of the Worrumba Anticline, and is characterised by a prominent outcropping lode of hydrothermal magnetite surrounded by historical artisanal copper and precious metal workings. Iron King is home to the deepest mine shaft identified to date at the MCCP, which recent measurements indicated extends more than 100m depth. The geology of the Iron King prospect indicates a large skarn system is present, and magnetic and gravity geophysics shows a large coincident grav-mag anomaly extending to significant depths beneath the outcropping exposures. There has been no recorded drilling at Iron King, which remains a priority drill target once Native Title clearance is obtained for this area. 

Figure 1. MCP Project outline showing priority exploration targets, the main structural feature being the Worrumba Anticline, and the Analytical Signal magnetics image.

Figure 2. Morgans Creek RAB drilling showing significant intercepts and max TREO grades. Also, lab assay status, the mapped Yednalue quartzite unit, previous Taruga 2021 drilling, and high-resolution ground magnetics TMI image.

Figure 3. Regional Morgans Creek RAB drilling showing significant intercepts and max TREO grades. Also, lab assay status, the mapped Yednalue quartzite unit, previous Taruga 2021 drilling, and high-resolution ground magnetics TMI image.

Figure 4. Cross Section A-A’ colour coded by TREO grade. Note multiple holes on section either end in mineralisation or have assays pending. The base of mineralisation has not yet been found.

Figure 5. Cross Section B-B’ colour coded by TREO grade. Note multiple holes on section either end in mineralisation.

Figure 6. Pie chart showing percentages of individual rare earth element oxides for all 2022 RAB drilling over 250ppm TREO.

Figure 7. Pie chart showing percentages of heavy and light rare earth element oxides for all 2022 RAB drilling over 250ppm TREO.