A gravity survey has provided further evidence that the Whaleshark project is prospective for IOCG, adding further weight to Miramar’s decision to focus on the emerging Gascoyne Mineral Province.

Modelling of the detailed gravity data collected during 2022 identified a discrete gravity anomaly within the neck of the Whaleshark granite which is cross-cut by a northwest-trending structure interpreted from aeromagnetic data.

Miramar Resources (ASX:M2R) has already received Western Australian state government Programme of Work approval for up to two diamond holes to test the gravity anomaly and has also submitted an application for co-funded drilling under the Exploration Incentive Scheme.

While exploration at Whaleshark is still at a very early stage, its prospectivity for IOCG (iron oxide copper-gold) mineralisation lends credence to the company’s belief that the Gascoyne province is prospective for a range of commodities.

This is highlighted by a detailed aeromagnetic and radiometric survey carried out in late 2022 at the Bangemall project which outlined several magnetic and/or radiometric anomalies on the Dooley Downs tenement that are indicators of rare earths mineralisation.

“We have a number of fantastic discovery opportunities right across our project portfolio but the Gascoyne region has really heated up over the last 12-18 months,” executive chairman Allan Kelly said.

“Now that we have completed regional-scale targeting on our granted projects, we are looking forward to focussing on our more advanced targets this year.

“We’re excited about the potential at Whaleshark and/or Bangemall with a new IOCG, REE or Ni-Cu-PGE discovery a real possibility at these project sites.”

Whaleshark gravity survey

Beside being cross cut by the northwest-trending structure, the gravity anomaly at Whaleshark is also coincident with surface geochemical anomalism seen in mobile metal ion soil analysis carried out in 2021 and geochemical anomalism seen in “interface” aircore drilling conducted during 2022.

Additionally, the gravity anomaly is also adjacent to a bulge and increase in the magnetic anomaly in the surrounding banded iron formation which may be caused by an accumulation of magnetite +/- IOCG mineralisation.

The company’s modelling indicates the source of the gravity anomalies could be as shallow as 80-100m below surface and therefore just beyond the reach of the shallower aircore drilling.

It added that the juxtaposition of a gravity and magnetic anomaly is a classic signature of many large IOCG deposits, whilst the scale of the combined geochemical and gravity target is similar to the large Ernest Henry IOCG deposit in Queensland.

Drilling will begin once a heritage survey over the proposed drill sites is completed.

Other Gascoyne exploration

Miramar plans to test the Eden Bore target identified by its detailed magnetic and radiometric survey with systematic soil and/or auger sampling, followed by drilling.

Eden Bore is a large circular magnetic anomaly at the contact between Edmund and Collier Basin rocks that is coincident with a strong thorium and uranium anomaly.

It is also planning a reconnaissance site visit of the Mount Vernon target, where limited historical exploration work identified anomalous nickel-copper and platinum group elements in sampling and drilling.

Once this is completed, it will carry out a systematic sampling program to test the late-time electromagnetic anomalies identified by a detailed magnetic and electromagnetic survey flown over the target in early 2022.




This article was developed in collaboration with Miramar Resources, a Stockhead advertiser at the time of publishing.


This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.