Alvo Minerals has identified a high-conductance off-hole conductor and multiple untested targets at its Touro copper-zinc prospect in Brazil. An environmental licence now allows Phase 2 drilling across roughly 500 metres of previously inaccessible strike.
- 590-660 siemens off-hole conductor identified at Touro
- Conductance is about 10 times the original surface FLEM response
- Metal Factor anomaly extends at least 500 metres south of drilled ground
- Phase 2 drilling cleared across approximately 500 metres of strike
- Entre Rios downgraded after no significant mineralised intercept
Touro’s strongest conductor remains untested
Alvo Minerals Limited (ASX:ALV) has found what may be its most compelling drill target yet at the Touro prospect, where a downhole electromagnetic survey has modelled an off-hole conductor with estimated conductance of 590-660 siemens. That response is about 10 times stronger than the original surface FLEM signal, although the conductor itself has not yet been drilled.
The interpretation matters because stronger conductance can be associated with more massive sulphides. Alvo says drilling in hole PDT-132 appears to have passed through mineralisation between shallower disseminated sulphides and the deeper, higher-conductance zone. The company has therefore ranked the deeper conductor as a priority target rather than treating the latest hole as a complete test of the system.
New modelling expands the Touro corridor
Alvo’s preliminary 3D model combines DHEM, induced polarisation and structural logging across the 1.8-kilometre Touro corridor. Drilling to date has focused on roughly 1.1 kilometres of that trend, while the reinterpretation has identified additional targets along strike and down-dip.
A Metal Factor anomaly, which combines high chargeability and low resistivity, appears to extend at least 500 metres south of the previously drilled area. Alvo interprets that continuation as potentially linked to disseminated sulphide mineralisation, with faults possibly offsetting the anomaly. Further surface geochemical sampling is planned to test that interpretation.
Licence removes access barrier for Phase 2 drilling
The company has received the environmental licence needed to drill into about 500 metres of central Touro strike that was previously inaccessible. Alvo says Phase 2 planning will prioritise the highest-conductance electromagnetic targets and the strongest Metal Factor anomalies.
Existing drilling has already confirmed mineralisation continuity, including 9.3 metres at 0.7% copper and 1.6% zinc from 55.3 metres in PDT-117, and a narrower 2.3-metre interval at 0.8% copper, 0.4% zinc, 57 grams per tonne silver and 0.43 grams per tonne gold from 126.9 metres in PDT-124. The northern PDT-132 hole returned 0.8 metres at 0.46% copper and 2.33% zinc, plus 5.7 metres at 0.11% copper and 0.54% zinc, within a broader 10-metre mineralised interval.
Esperanza advances while Entre Rios falls back
At nearby Esperanza, preliminary DHEM modelling has produced off-hole plates of 1,300-1,500 siemens in holes PDZ-128 and PDZ-130. Alvo says conductance at those levels is materially stronger than the surface responses and is comparable with mineralised conductors seen elsewhere at Palma, including the C3 deposit. Additional surface FLEM is planned before the next drill test.
The exploration picture is less encouraging at Entre Rios. A single hole intersected strong hydrothermal alteration but no significant assay interval, while the targeted conductors were associated with barren, pyrrhotite-dominant sulphides and no meaningful off-hole conductor was detected. Alvo has consequently downgraded the prospect pending further work.
Drilling must convert geophysical promise
Palma’s existing C1, C3 and C4 deposits carry a JORC 2012 resource of 7.6 million tonnes at 2.0% copper equivalent, but Touro remains an exploration prospect rather than a mineral resource. The reported equivalent grades also rely on assumed metal prices and recoveries based on testwork elsewhere at Palma; no metallurgical testwork has been completed on Touro, Esperanza or Entre Rios material.
The next meaningful test is therefore straightforward: whether Phase 2 drilling intersects massive sulphides where the model predicts them. Until those holes are drilled and assayed, the 590-660 siemens response is an enticing target, not yet an additional body of copper and zinc.
Bottom Line?
The licence turns Touro’s strongest targets from geophysical anomalies into drillable propositions, but the investment case still depends on assays from the deeper conductor and the newly opened strike.
Questions in the middle?
- Will drilling intersect massive sulphides within the 590-660 siemens off-hole conductor?
- Does the Metal Factor anomaly continue into economically meaningful mineralisation across the additional 500 metres of strike?
- Can Esperanza’s unusually strong conductors produce mineralisation comparable with the C3 deposit?