Impact, IGO reveal ‘compelling’ EM conductor at Broken Hill
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Impact and IGO have identified a large and strong electromagnetic conductor that has jumped straight onto their priority target list for the Broken Hill project.
The 420m by 85m conductor located at a depth of about 350m was discovered through the joint venture’s extensive and ongoing EM survey over the project and is located about 1,000m from drill hole PSD002 that intersected massive sulphide with similar electrical conductance to the new conductor.
Importantly for Impact Minerals (ASX:IPT) and IGO Limited (ASX:IGO), the conductor lies within a major shear zone that is interpreted to be a possible feeder zone for the extensively mineralised nine-kilometre long Moorkai Trend.
Such feeder zones are prime targets for massive sulphide mineralisation.
IGO is spending an initial $6m on exploration at Broken Hill over four years to earn a 51% stake in the project. A further $12m in expenditure over another four years will take its stake up to 75%.
“It is fantastic to have made an early breakthrough on the major EM survey at Broken Hill with our joint venture partner IGO,” Impact managing director Dr Mike Jones said.
“The EM conductor lies within a major structure that may have been a feeder zone for the entire Moorkai Trend and in an area with no previous exploration.
“It is a very compelling target, and we look forward to receiving more results from the EM survey as it progresses.”
The new EM conductor within the Platinum Springs prospect has been modelled to have a high conductance of about 8,000 siemens that when combined with its dimensions, is considered prospective for massive sulphide mineralisation.
This is supported by its proximity to PSD002 that returned a 0.6m interval grading 11.5 grams per tonne (g/t) platinum, 25.6 g/t palladium, 1.4 g/t gold, 7.6% copper, 7.4% nickel and 44.3 g/t silver from a depth of 57.1m down-hole.
Down-hole EM surveying of the 2016 well indicated the intersected massive sulphide had a high conductance greater than 5,000 siemens and similar to that modelled for the new conductor.
Platinum Springs is located at the southern end of the 9km long Moorkai Trend, which is the only part that has received detailed historical exploration on top of the high-grade rock chip samples collected across its entire length.
However, this returned limited success due to the apparent discontinuous and erratic nature of the mineralisation and poor understanding of controls on its distribution at that time.
Work by Impact has since identified high grades of nickel-copper-PGM’s in a channel-like structure at the base of the ultramafic unit that has yet to be followed up.
This was identified in close-spaced drilling using the company’s proprietary ratio for PGM mineralisation and was the first coherent zone of mineralisation defined in the area in over 30 years of exploration, which led to the development of a new geological framework within which to understand the Moorkai Trend.
The joint venture is continuing the EM survey, which is expected to take another three months to complete.
Once this is completed, they will then assess this conductor and any others that might be found for further work.
This article was developed in collaboration with Impact Minerals, 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.