Key Highlights

  • Orpheus drilled 18 rotary mud holes totalling 3,600m at the Erudina Uranium Prospect, with downhole logging completed in 16 holes.
  • Nine logged holes recorded peak results above 100 ppm eU3O8, including two above 400 ppm.
  • Two north-south corridors of at least 2.2km in strike, Siccus East and Siccus West, were defined by redox changes in the Eyre Formation.
  • Siccus North and Siccus South remain under interpretation, with future drilling timing yet to be determined.

Orpheus Uranium Limited (ASX:ORP) has completed its first drilling program at the Erudina Uranium Prospect, part of the broader Frome Project in South Australia, and reported that the results refined four target areas now named Siccus North, Siccus East, Siccus South and Siccus West. The program comprised 18 rotary mud holes totalling 3,600m, announced on 22 October 2026.

Erudina lies within the Callabonna Sub-Basin and the underlying Frome Embayment. Exploration targets sandstone-hosted uranium associated with redox transitions in the Tertiary (Eocene) Eyre Formation, with potential to extend assessment into the overlying Miocene Namba Formation and underlying Cretaceous sediments.

Drilling Results and Logging

Downhole geophysical logging was completed in 16 of the 18 holes. Nine of the logged holes recorded peak results exceeding 100 ppm equivalent uranium oxide (eU3O8), including two above 400 ppm, with the highest single-hole readings of 416 ppm in CURE0004 and 406 ppm in CURE0012. Six holes targeted oxidised sand packages in which depleted uranium grades were expected.

Appendix intervals include 1.44 m at an average of 197.2 ppm eU3O8 in CURE0004 from 189.23 m, and a shorter 0.56 m interval at 206.2 ppm from 170.65 m. Holes with a maximum of 100 ppm or more are treated as significant, and all drilling was vertical.

The regional program tested an updated interpretation of historical drilling to rank redox corridors. Orpheus said geological observations were largely consistent with that interpretation, and the work was designed partly to constrain the settings in which mineralisation could occur, since roll-front deposits can form narrow, sinuous fronts. Uranium carried in oxidised groundwater may be deposited where it meets reducing conditions, and the presence of oxidised sediments within a generally reduced basin sequence supports that mechanism, according to the company.

Siccus East, West and the Deeper Concept

At Siccus East, current and historical holes identified a priority corridor interpreted to extend about 2.2 km along strike and up to 250 m wide. Initial field logs of CURE0017 and CURE0018 show oxidised Eyre Formation sediments in one hole and reduced sediments in the other. At Siccus West, contrasting redox conditions between CURE0007 and CURE0008 support a redox boundary between the holes.

Orpheus stressed that these dimensions describe the area selected for investigation rather than a demonstrated mineralised body, and that not every redox boundary is mineralised. Drilling at the project also remains relatively widely spaced compared with known deposits. The company considers the footprints comparable in scale with known Callabonna Sub-Basin deposits, including Heathgate's Four Mile East, Pannikan and Pepegoona projects and Boss Energy's Honeymoon and Gould's Dam.

Siccus North is a potential northern continuation of the corridors, and Siccus South is an early-stage concept. A deeper unit in CURE0007, possibly a Cretaceous unit containing diamictitic material or a thicker basement weathering profile, remains unresolved; the hole was abandoned at 227 m because of water loss. Heathgate's Four Mile West, hosted in a Mesozoic diamictite, provides regional context, although no stratigraphic correlation has been established.

Next Phase and Operating Experience

The next phase will integrate and validate data, rank the four areas and develop follow-up drilling to test the link between redox boundaries and mineralisation. The longer-term objective is an Exploration Target, subject to further drilling and, if results warrant, a JORC-compliant resource. Timing of future programs will be set in the context of Orpheus's broader uranium portfolio. Managing Director Clinton Dubieniecki said the results supported key geological and geochemical predictions and gave a clearer basis for further exploration.

The campaign was the first drilling in the area in roughly 15 years. A weather event interrupted it, additional work was required to source water, and mobilising the drilling team from interstate called for flexible rostering. Orpheus said the experience provides a firmer basis for future programs across its portfolio.

Where the Program Leaves Frome

In summary, the 18-hole program converted a historical-data model into four named target areas, with two corridors of at least 2.2km in strike defined by redox contrasts and nine holes peaking above 100 ppm eU3O8. Orpheus cautions that its redox interpretation is preliminary and conceptual, and that a redox front does not by itself confirm uranium mineralisation.

Frome remains in the Advanced Exploration category of the company's project pipeline, alongside its other South Australian sedimentary-style uranium assets.