Key Highlights

  • Six hydrogeological bores totalling 1,378 metres were completed: 764 metres of monitoring bores and 614 metres of production bores.
  • Three production bores and three monitoring bores were built at Windabout and Emmie Bluff for pump testing and groundwater monitoring.
  • The rig now moves to Oakden for about 5 to 6 shallow RC holes totalling 300 to 400 metres around historical hole OK36.
  • OK36 intersected 3m at 1.15% Cu from 39m in Tapley Hill Formation black shale, a historical result Coda intends to verify.

Coda Minerals Limited (ASX:COD) has finished its hydrogeological drilling programme at the 100%-owned Elizabeth Creek Copper-Silver Project in South Australia and is moving its drill rig to exploration work. The six-hole programme added bores at the Windabout open-pit and Emmie Bluff underground prospects, and the rig will now turn to the Oakden prospect to test shallow historical copper mineralisation.

Six Bores Built at Windabout and Emmie Bluff

The programme comprised one production bore and one monitoring bore at Windabout and two production and two monitoring bores at Emmie Bluff. Total drilling came to 1,378 metres, made up of 764 metres of monitoring bores and 614 metres of production bores. At Emmie Bluff, PB26EB0001 reached 410 metres and MB26EB0001 reached 479 metres, while PB26EB0002 and MB26EB0002 ended at 126 and 158 metres. At Windabout, PB26WIND0001 was drilled to 78 metres and MB26WIND0001 to 127 metres. Drilling ran from 21 July to 24 October 2026.

Each bore was completed and constructed as designed. Pump testing will draw water from each of the three production bores for up to 48 hours at a time, with the groundwater response logged in the monitoring bores. Testing starts as soon as practicable after onsite earthworks, which include large turkey's nest dams to control saline water run-off. Coda expects that work to begin later in 2026, following the Oakden programme.

How the Water Data Feeds Approvals and the PFS

The pump-test data will go into the regional hydrogeological model being built for the Mining Lease Application and environmental approvals pathway. The model is intended to help Coda anticipate impacts on surrounding water users and groundwater-dependent ecosystems, although surveys so far have not identified any such ecosystems at Elizabeth Creek. The same model supports the ongoing Pre-Feasibility Study through dewatering and depressurisation planning for the open-pit and underground workings, underground geotechnical parameters and the site water balance.

The water balance result will partly decide the next field steps. If water availability is flagged as a concern, a further programme to define water resources and plan a production bore field may be needed. If it is judged low, that programme may be deferred to the Definitive Feasibility Study.

None of the holes was designed to test for mineralisation. MB26EB0001, located north-west of DD25EB0038, served a secondary exploration purpose but did not intersect Tapley Hill Formation black shale. It was drilled well outside the Emmie Bluff Mineral Resource outline, so the result has no bearing on that estimate, and it has been added to the geological model to help refine exploration targeting south of Emmie Bluff.

Oakden Exploration Programme

Oakden lies about 15 kilometres south-south-west of the MG14 Mineral Resource and the historic Cattle Grid open pit. The programme follows historical drillhole OK36, which intersected 3m at 1.15% Cu from 39m in relatively shallow Tapley Hill Formation black shale. Coda notes that detailed assay and QA/QC information for the result is not available, and a key purpose is to test its reliability and repeatability.

The first phase will be about 5 to 6 shallow RC holes for around 300 to 400 metres near OK36. The holes are designed to confirm the historical intersection, test continuity at distances of roughly 50 to 200 metres and confirm the interpreted geometry of the Tapley Hill Formation. Depending on results, Coda will consider a second phase of about 12 to 22 holes across the broader interpreted corridor. CEO Chris Stevens described the programme as a focused, low-cost test that would establish whether mineralisation extends beyond the original intersection.

Elizabeth Creek Resource Base

Elizabeth Creek's aggregated Mineral Resources total 65.5 million tonnes, with 705,800 tonnes of contained copper, 33,000 tonnes of contained cobalt and 28 million ounces of contained silver. Emmie Bluff accounts for 40.2 million tonnes at 1.3% Cu, 1.9% copper equivalent, and Windabout for 17.7 million tonnes at 0.8% Cu. The drilling reported here adds groundwater infrastructure around those deposits and sets up the first test at Oakden.