Dalaroo Metals has identified coincident geophysical and geochemical features at its Watheroo Cu-Ni-PGE prospect, including a modelled chargeability response of approximately 18 mV/V. The results support plans for deep RC drilling, but the anomalies remain unproven and could have non-mineralisation sources.
- 6,300m DDIP survey completed across three lines
- Modelled chargeability response reaches approximately 18 mV/V
- Anomalies coincide with magnetic, resistivity and soil geochemistry features
- Deep RC holes of approximately 300m planned
- IP responses remain non-diagnostic and require drilling confirmation
Dalaroo Metals Ltd (ASX:DAL) has moved its Watheroo Cu-Ni-PGE prospect closer to its first deep drill test after a 6,300-metre induced polarisation survey outlined coincident chargeability, resistivity and magnetic features beneath a large surface geochemical footprint.
The strongest modelled chargeability response reached approximately 18 mV/V on one survey line, while observed survey data recorded values of up to 19.4 mV/V. Dalaroo said the results refine several priority targets within its 100%-owned Watheroo Project in Western Australia’s mid-north Wheatbelt, with reverse-circulation holes of approximately 300 metres planned subject to funding, landowner access and statutory approvals.
IP Survey Defines Deep Drill Targets
The survey covered three east-west profiles, with lines roughly 300 metres apart and stations at nominal 100-metre spacing. Its most prominent feature was a steeply dipping chargeability response near a sharp resistivity boundary and a break in the airborne magnetic signature.
That combination matters because Dalaroo is exploring for magmatic nickel-copper-PGE sulphides associated with a buried mafic-ultramafic intrusive system. The company’s interpretation is also supported by a 7-kilometre by 3-kilometre magnetic footprint, mapped olivine gabbro and serpentinite, and soil results including peak values of 284 parts per million copper, 176 parts per million nickel and up to 10 parts per billion each of platinum, palladium and gold.
Geophysical Evidence Comes with Important Limits
The survey is encouraging as a targeting exercise, but it is not a discovery announcement. Induced polarisation responses are not diagnostic of sulphides and may also arise from graphite, clay-rich rocks, weathering products or saline groundwater. Dalaroo’s own disclosure says drilling is required to establish the source of the anomalies.
Data quality also varies across the survey. Conductive soils reduced signal amplitudes at depth in places, creating noisier decay curves and lower repeatability. The company cautioned that these conditions may overstate calculated chargeability amplitudes, while sensitivity declines with depth. The resistivity inversion on the line containing the approximately 18 mV/V modelled response produced a relatively high RMS misfit of 26.78%, compared with 8.72% and 8.52% on the other two lines.
Drilling to Test the Watheroo Model
Dalaroo intends to prioritise targets where chargeability overlaps the interpreted magnetic and resistivity boundary, elevated Cu-Ni-PGE and sulphur geochemistry, intrusive contacts, and extensions of the response at depth or along strike. A conductive and chargeable zone remains open to the south and at depth beyond the current survey coverage, although that apparent continuation is also subject to the limitations of the inversion.
The company also plans approximately 360 additional soil samples, supported by stream-sediment sampling, rock-chip work and geological mapping. If drilling proceeds, downhole electromagnetic surveys may be considered to search for conductors beyond the immediate holes. The key test now is whether the attractive convergence of datasets survives contact with the drill bit, rather than whether another geophysical model can make the target look larger.
Bottom Line?
Watheroo has reached a credible drill-targeting stage, but the investment case still turns on whether the IP responses represent sulphide-bearing rock rather than conductive geology or modelling effects.
Questions in the middle?
- When will Dalaroo secure the funding, access and approvals needed for the planned deep RC program?
- Will drilling confirm sulphide mineralisation at the magnetic and resistivity boundary?
- How much of the apparently open response to the south and at depth can be validated beyond the current survey coverage?